The Biopsychosocial Model of Addiction Monica C

CHAPTER 6

The Biopsychosocial Model of Addiction Monica C. Skewes*, Vivian M. Gonzalez$ *University of Alaska Fairbanks, Fairbanks, AK, USA, $University of Alaska Anchorage, Anchorage, AK, USA

OUTLINE

Biopsychosocial vs. Biomedical Models of Addiction 61 Spouses and Intimate Partners 67 Other Individual Difference Variables that Influence Conceptual Models of Addictive Behavior 62 Substance Use 67 Biopsychosocial Model of Addiction 62 Ethnicity and Culture 67 Gender 67 Biological Factors and the Development of Environmental Influences on Substance Use 67 Addictive Behaviors 63 The Biopsychosocial Model and Addiction Psychosocial Factors and the Development of Treatment 68 Addictive Behaviors 64 Natural Recovery 68 Risk Factors in Children 64 Medication 68 Personality and Temperament 64 Classical and Operant Conditioning 64 Psychosocial Factors in the Treatment of Addiction 69 Outcome Expectancies 65 Readiness to Change 69 Self-efficacy 66 Self-efficacy 69 Social Influences on Substance Use 66 Summary 69 Families 66 Peers 66

BIOPSYCHOSOCIAL VS. BIOMEDICAL Contemporary medical disease models acknowledge the MODELS OF ADDICTION influence of social, psychological, and behavioral dimensions of addiction; however, these dimensions The biopsychosocial model of addiction posits that are viewed as relatively less important in the etiology biological/genetic, psychological, and sociocultural and treatment of addiction. The medical disease model factors contribute to substance use and all must be taken favors reductionism, whereby underlying biomedical into consideration in prevention and treatment efforts. causes for addiction are primarily implicated in the This model emerged in response to criticisms of the etiology/cause of the disorder, and mind–body dualism, biomedical model, which has historically dominated where the mind and the body are viewed as separate the field of addiction studies. The traditional biomedical and as not significantly affecting one another. Despite model was developed and is espoused by medical scien- widespread favor among many scientists and healthcare tists for the study of disease, and its proponents also practitioners, evidence from research studies of addic- view addiction as a chronically relapsing brain disease tive behaviors does not support the medical disease with a genetic/biochemical cause. The biomedical or model of addiction; instead, a biopsychosocial model disease model of addiction views addiction as the mani- that gives equal importance to biological/genetic, festation of disturbances in measurable biochemical or psychological, and sociocultural factors better fits the neurophysiological processes in the afflicted individual. available data.

In 1977, psychiatrist George Engel authored a seminal the addictive problem and the responsibility for solving paper calling for the abandonment of the biomedical the addictive problem. The moral model holds that model of illness in favor of a biopsychosocial model. people who suffer from problems of addiction are Engel identified numerous problems with the biomed- responsible for both acquiring and solving the problem. ical model that would be alleviated by the adoption of People who become addicted are seen as morally weak a biopsychosocial model that recognizes biological, with poor willpower, and they must will their way psychological, social, and cultural influences on illness. through addiction in order to recover. There is little For example, the biomedical model views biochemical support for this model in the literature. The enlighten- abnormalities as the cause of any illness, and posits ment model holds that the person is responsible for that correcting the biochemical abnormality will cure developing the addiction, but is not responsible for the illness. However, in many disorders, a person may solving the problem. The enlightenment model is remain ill after the biochemical abnormality has been espoused by Alcoholics Anonymous and other 12-step corrected and, conversely, a person may never become philosophies, and requires people to seek recovery by ill even in the presence of an abnormality. For example, turning the problem over to a higher power. Only when infected with the virus that causes the common a higher power can cure addiction, and it is the person’s cold, some research participants become ill and some task to form and strengthen a relationship with a spiri- do not. The biomedical model does not account for the tual entity so that this entity can solve the addiction finding that, among people with similar genetic predis- problem. The medical/disease model emerged in positions or physiological problems, some people response to the moral and enlightenment models that develop an illness while others remain well. Engel placed blame on the addict for his or her problem. In surmised that psychological and sociocultural factors the medical model, the addict is responsible neither for must explain the differences in the disease state among the development of the problem nor for its resolution. people with the same biochemical abnormalities. This model posits a biological/genetic predisposition It has been well established that illness is not merely for addiction, an underlying disease process, and assumes the result of biochemical dysfunction or abnormality, as that the disease is progressive. The medical/disease some people become ill in the absence of an abnormality model fails to account for the finding that many people or dysfunction. The effects of stress on illness have been with problems of addiction do recover without profes- well supported in the literature, as has the role of expec- sional treatment. Finally, the compensatory model holds tation on illness and health. The placebo effect, where an that people are not responsible for developing the addic- inert ingredient can result in biochemical reactions for tive problem, but are responsible for their own recovery. the person who believes he or she is ingesting a drug, In the compensatory model, the role of multiple factors is evidence for the role of expectation in illness, and in the development of addictive behavior is noted supports Engel’s view of a connected mind–body expe- (including biological predisposition, early experiences, rience. There also is evidence for the importance of the and social and cultural variables), and the continued patient–provider relationship in healing; if psychosocial use of substances is viewed as a way to cope with stress. variables were not important, it would not make sense Of these four models, the compensatory model is the for rapport building and communication between the most similar to the biopsychosocial model. physician and the patient to have such strong influences on health outcomes. Moreover, if illness is caused only by the existence of a physical abnormality, then it should BIOPSYCHOSOCIAL MODEL OF be cured by correcting the deviance, but this is not ADDICTION always the case. Most illnesses, disorders, and syndromes, including disorders of addiction, are caused Science has not discovered a single factor that can by the interaction of numerous factors – biological, explain why some people are able to use substances psychological, social, cultural, cognitive, and environ- without progressing to addiction, while others abuse mental. Therefore, these factors must be addressed in or become dependent on substances. Instead, the avail- order to result in a recovered state. able evidence suggests that biological, genetic, personality, psychological, cognitive, social, cultural, and environmental factors interact to produce the substance CONCEPTUAL MODELS OF ADDICTIVE use disorder, and multiple factors must be addressed in BEHAVIOR prevention and treatment programs. The interaction of these factors to produce substance use problems is the A discussion of helping and coping by Brickman and core tenet of the biopsychosocial model of addiction. colleagues identified four models of addiction based on This model is a way to understand and explain the beliefs about attributions of responsibility for acquiring problem of addiction, but has not generated testable

I. THE NATURE OF ADDICTION BIOLOGICAL FACTORS AND THE DEVELOPMENT OF ADDICTIVE BEHAVIORS 63 hypotheses as have theories of behavior change like the consumption. Further, sons of an alcohol-dependent Health Belief Model or the Theory of Reasoned Action/ parent have decreased EEG alpha rhythms, also found Theory of Planned Behavior (TRA/TPB). The essence of in people with current alcohol dependence. Other the model is that the mind and the body are connected studies have found that the sons of an alcohol-dependent and both the mind and the body affect the development parent have lower language functioning, lower learning and the progression of addiction within a social and achievement, lower verbal intelligence, and other neuro- cultural context. Only by considering all of these factors psychological differences when compared to controls. can addiction be accurately conceptualized. There is evidence that children of an alcohol-dependent parent who become alcohol dependent themselves have a worse prognosis than alcohol-dependent people who BIOLOGICAL FACTORS AND THE are not the children of alcohol-dependent parents. For DEVELOPMENT OF ADDICTIVE example, the children of an alcohol-dependent parent BEHAVIORS show symptoms of alcohol problems earlier, have greater physical dependency on alcohol, and report Given the right environment, biological and genetic less control over their drinking. predispositions may increase the risk of substance use A genetic predisposition toward addiction does not problems. Adoption and twin studies have found that influence the substance of choice to which a person substance abuse is to some extent heritable. Male chil- may become addicted; instead, it is associated with an dren of an alcohol-dependent parent have four times increased propensity toward addictive behavior in the risk of becoming problem drinkers compared with general. It also is important to note that genetic factors the children of nondependent parents, while female may be protective against alcohol use disorders. People children of alcohol-dependent mothers evidence a three- of Asian descent are more likely to lack one isozyme of fold greater risk. It has been reported that 30.8% of a liver enzyme known as alcohol dehydrogenase that people with alcohol dependence had at least one aids in the metabolism of alcohol in the liver. People alcohol-dependent parent. Among adults with alcohol with this genetic variation have a flushing reaction to dependence, 27% have alcohol-dependent fathers and alcohol, characterized by flushed, reddish skin, and are 4.9% have alcohol-dependent mothers, compared with much less likely to ever develop alcohol problems. alcohol dependence among 5.2% of fathers and 1.2% of Research from the fields of genetics and biochemistry mothers of people without alcohol dependence. Among has identified other biological risk factors for addiction. twin pairs in which one twin was diagnosed with People with impulse control disorders, including people alcohol dependence, there is a significant difference in with substance abuse problems and gamblers, are statis- the proband concordance rate among monozygotic tically more likely to have the dopamine D2A1 gene (54.2%) and dizyogtic twins (31.5%). Calculated herita- than controls. This genetic polymorphism is associated bility ranges from 40–90% across studies, with more with reduced D2 receptor density and deficits in the chronic and severe forms of alcohol dependence dopaminergic reward pathway. Research has found showing greater estimates of heritability. However, it is that those with low D2 receptor density are more likely important to note that someone with a strong genetic to seek out pleasurable activities including alcohol use, predisposition to addiction still needs to engage in drug use, and gambling. This may translate into substance use before the addictive behavior becomes increased likelihood of experiencing problems associ- manifest. ated with addictive behaviors. Once alcohol is consumed, however, children of an Further evidence of the heritability of the risk for alcohol-dependent parent experience the effects of alcohol dependence can be found in animal studies. alcohol differently than the children of nondependent Researchers have been able to use selective breeding to parents. For example, research on subjective experiences develop strains of rats that differ in their liking of of alcohol intoxication and body sway while intoxicated alcohol. One strain of rat (C57BL/6) has been bred to found that sons of an alcohol-dependent parent respond prefer alcohol over water. These animals seek out less intensely to moderate doses of alcohol. When given alcohol, ingest it willingly, engage in efforts to get the same amount of alcohol as controls, sons of an alcohol, and become physically dependent on it, alcohol-dependent parent had less body sway and showing signs of tolerance and withdrawal. Other were less likely to report feeling intoxicated. Follow-up strains of rats have been bred to self-administer other studies have found that decreased subjective intoxica- drugs of abuse at high rates. The fact that an alcohol- tion predicted later development of alcohol use disor- preferring strain of rat has been developed is strong ders. Other studies have found that the children of an evidence of the influence of heritability on alcohol use alcohol-dependent parent are less sensitive to the negative behavior. Furthermore, studies have found deficits in consequences of alcohol, resulting in increased alcohol serotonin in particular brain regions of rats that have

I. THE NATURE OF ADDICTION 64 6. THE BIOPSYCHOSOCIAL MODEL OF ADDICTION been bred to like alcohol. Despite the strong evidence of in adulthood. Antisocial personality disorder is highly the role of genetic influence on alcohol use behavior, comorbid with substance abuse and dependence, and biology is still insufficient to account for the entirety of antisocial behaviors in childhood are strong predictors the problem. There still remain cases where people of substance problems in adulthood, independent of with no known genetic risk become addicted and cases a family history of substance abuse. where people with great genetic risk do not. The biopsychosocial model of addiction acknowledges that Personality and Temperament psychosocial variables also are needed to explain these occurrences and that these variables may interact with Addictive behaviors result from the interaction genetic and biological risks to cause addiction. between genetic predisposition and psychosocial variables, including personality and temperament. Person- ality variables that impact later substance use include PSYCHOSOCIAL FACTORS AND THE high novelty/sensation seeking, low harm avoidance, DEVELOPMENT OF ADDICTIVE negative affectivity, and reward dependence. Other BEHAVIORS temperament variables that predict later substance problems are low attention capacity, high emotionality, Researchers have discovered consistent predictors of low sociability, and impulsivity. A difficult temperament drug use initiation and subsequent use across multiple in childhood – defined as a high activity level, low flex- substances of abuse, including personality variables, ibility, low task orientation, mood instability, and social learning factors, and higher-order cognitive processes. withdrawal – has been shown to predict substance Substance abuse is highly comorbid with affective disor- abuse in adolescence. One research study found that ders and other psychiatric diagnoses, although some a difficult temperament in childhood was a stronger psychiatric problems (e.g. depression and anxiety) may predictor of later alcohol dependence than a family be effects of the substance use as well as causal factors. history of alcohol dependence. Regarding the Big Five Many (but not all) substance abusers have a history of factors of personality (neuroticism, extraversion, open- antisocial behavior, nonconformity, deviance, acting ness to experience, agreeableness, and conscientious- out, impulsivity, and low self-esteem; however, these ness), a family history of alcohol dependence is also can be the effects of substance misuse. Research positively associated with openness to experience and establishing the role of psychosocial factors in the devel- negatively associated with agreeableness and conscien- opment of addictive behaviors provides evidence that tiousness. Unconventionality and deviant behavior are addiction is a multifactorial problem, not a disease strong predictors of substance abuse across multiple solely caused by a measureable underlying physiolog- research studies. In addition to increasing risk for ical abnormality or deficit, and provides support for substance use, temperament may influence adolescents’ the biopsychosocial model of addiction. decisions when forming peer groups, which may then directly impact substance use. Adolescents who are more deviant and less conventional tend to select peers Risk Factors in Children who also are more deviant and less conventional, further Much research has been conducted on childhood enhancing their risk for substance abuse. variables that increase the risk for alcohol dependence and substance use disorders. Consistently found in the Classical and Operant Conditioning literature is evidence for an increased likelihood of addiction among children who are victims of abuse Classical and operant conditioning are learning and who exhibit externalizing behaviors such as those processes that affect animal behavior, including addic- seen in conduct disorder, attention deficit/hyperactivity tive behaviors among humans. Classical conditioning disorder, and oppositional defiance. In particular, anti- works to establish a link between reflexive, involuntary social and deviant behaviors such as aggression, behaviors and antecedent conditions, whereas operant hostility, vandalism, sadistic behavior, rebelliousness, conditioning concerns the modification of voluntary and association with deviant peer groups place one at behavior in response to its consequences. In classical risk for substance use disorders later in life. One study conditioning, an unconditioned stimulus (US) is paired found that problem drinkers exhibited more external- with a conditioned stimulus (CS), resulting in a condi- izing behaviors in childhood than did moderate tioned behavioral response (CR) to the conditioned stim- drinkers, and moderate drinkers exhibited more of these ulus. For example, Pavlov’s dogs learned to associate the behaviors than did light drinkers. Other research has sound of a bell (the CS) with food (the US) to produce found that tolerance of deviance in adolescence is salivation (the CR). After several pairings of the bell a strong predictor of alcohol and other substance abuse with food, the bell itself became sufficiently linked

I. THE NATURE OF ADDICTION PSYCHOSOCIAL FACTORS AND THE DEVELOPMENT OF ADDICTIVE BEHAVIORS 65 with food to produce salivation even in the absence of conditioned link between a cue and the behavior, by food. Among people engaging in addictive behaviors, altering the reinforcement for the behavior, or both. an unconditioned stimulus (e.g., drug paraphernalia) Substance use functions as positive reinforcement can become paired with a conditioned stimulus (the when the pleasant effects of intoxication are interpreted drug) to produce a conditioned response (psychomotor as rewarding to an individual. At the same time, people stimulation). People (such as an addict’s drug-using use substances to cope with unpleasant emotions, to social network), places (such as locations where drugs manage stress, and to alleviate negative symptoms of are purchased or used), and things (such as drug para- withdrawal. In these ways, substance use also functions phernalia, alcohol bottles, or substance-related words) as a negative reinforcement. The more frequently one are linked to the unconditioned stimulus (the substance) uses substances as a reward or as a way of coping and take on the role of conditioned stimulus, evoking with negative emotions or life events, the stronger the a conditioned response (e.g., craving). Encountering association becomes and the more difficult it is to extin- the conditioned stimuli associated with substance use guish the substance use behavior. This partially accounts (i.e., triggers) is a strong precipitant of relapse among for the finding that treatment is more difficult and people in recovery from substance use disorders. relapse is more likely among individuals who have In operant conditioning, behavior is reinforced via longer histories of substance use. It also has been punishment, positive reinforcement (reward), or nega- suggested that use of substances to cope leads to an tive reinforcement (the removal of an adverse conse- erosion of alternative coping behaviors, thereby making quence). Reinforcement is any consequence that continued substance use and dependence more likely. increases or decreases the likelihood that a behavior will be repeated. Among people engaging in addictive Outcome Expectancies behaviors, operant conditioning affects the probability that the behavior will recur. For example, smoking One area of research that has uncovered some of the behavior may be positively reinforced by pleasurable strongest and most reliable effects of psychology on sensations caused by nicotine and simultaneously nega- addictive behavior is that of alcohol outcome expectan- tively reinforced by the elimination of nicotine cravings. cies. Addiction is not merely a physiological response All drugs of abuse act on the central nervous system and to something that feels good and is rewarding; it is influ- initially produce pleasant feelings and a hedonic state, enced strongly by the labeling, interpretation, and but people differ in how reinforcing they find these feel- meaning that a person ascribes to a substance of abuse. ings to be. People who enjoy the sensations produced by Outcome expectancies are conditioned cognitions; this substance intoxication (i.e., find intoxication to be posi- refers to a person’s beliefs about the effects that using tively reinforcing) are more likely to use substances to alcohol (or another substance) will bring about. People the point of intoxication again in the future than are who develop substance use problems report that using people who do not enjoy the feeling of intoxication. a substance results in positive, desired effects such as One study found that the degree of perceived reinforce- the ability to avoid or escape negative mood states. ment following initiation of drug use was predictive of Common alcohol expectancies, as identified and des- the magnitude of the resultant drug problem. cribed by Alan Marlatt, include relaxation and tension Classical and operant conditioning work together to reduction, positive global changes in experience, sexual produce a behavior chain, or a sequence of behavior enhancement, social and physical pleasure, increased that can be understood in terms of both its antecedents assertiveness, and increased arousal and interpersonal (classical conditioning) and consequences (operant power. People may learn what they can expect from conditioning). Antecedents are also known as cues. alcohol from prior experience or vicariously; indeed, Once a behavior chain has been activated, each cue evidence suggests that one need not have experience serves as the reinforcer of the behavior that occurred with alcohol in order to form strong expectancies about previously as well as the antecedent of the behavior its effects. Watching others model the behaviors associ- that follows. Cued habitual behaviors are both classi- ated with intoxication (e.g., becoming louder, becoming cally conditioned and reinforced or punished via operant more socially confident and engaged, and developing conditioning. For example, encountering a liquor store looseness of speech) can teach an observer what the may serve as a classically conditioned cue for a problem effects of alcohol consumption are, thereby creating drinker, which results in craving. Craving may then outcome expectancies. Experience with drinking may serve as a cue to consume alcohol, and this behavior then reinforce previously held beliefs about the positive may then be negatively reinforced by alleviating stress effects of alcohol. Expectancies also influence motives to or negative mood. By determining and understanding drink – people who state that they expect alcohol to help the behavior chain involved in addictive behaviors, relieve tension are more likely to turn to alcohol when intervention can be aimed at breaking the classically stressed. Heavier drinkers report more positive alcohol

I. THE NATURE OF ADDICTION 66 6. THE BIOPSYCHOSOCIAL MODEL OF ADDICTION outcome expectancies and fewer negative outcome role against the development of substance abuse. expectancies than lighter drinkers. Parental monitoring (supervision) and consistent disci- pline are associated with lower risk for substance abuse Self-efficacy among children. Among women, becoming a parent also is associated with decreased risk for drinking Another psychological variable that influences the problems. development of substance use disorders is Bandura’s concept of self-efficacy. Self-efficacy is defined as an Peers individual’s belief in his or her ability to perform Peers influence adolescents’ values, attitudes, and a certain behavior in order to achieve a desired outcome. behavior in multiple domains, including substance Self-efficacy for substance use is developed when one abuse. Having a peer group that uses substances is observes a model obtain and use substances. For a strong predictor of adolescent substance use, as is example, an adolescent may develop self-efficacy for the perception that one’s peer group endorses substance smoking by observing peers purchasing cigarettes at use. When adolescents associate with peers who hold a location that does not check identification, lighting socially deviant attitudes and beliefs, the risk of a cigarette, and inhaling the smoke. The adolescent’s substance use increases. Friends’ smoking is among confidence in his or her ability to smoke is thereby the strongest predictors of adolescent smoking behavior. increased. However, self-efficacy also refers to one’s Peer group involvement is thought to impact substance belief that he or she is capable of handling a stressful use through interaction with other risk factors, including or challenging situation without using substances. family problems, stress, mental health, and self-esteem. Research has found that people are more likely to use Among adolescents who drink, the most important substances in situations where they feel unable to cope reasons for alcohol use were to socialize with friends, with the demands of the situation or negative affect. cope with tension and anxiety (especially regarding As one uses substances more and more often to cope interactions with the members of the opposite sex), with stress or other life problems, the use of other improve mood, and alleviate boredom. Male adoles- more adaptive coping strategies decreases, which then cents, who have higher rates of alcohol use than females, results in reduced self-efficacy for the use of these alter- also have higher rates of involvement with peer groups native coping skills. This also translates into decreased that maintain deviant attitudes. self-efficacy in one’s ability to refuse substances in the Peer influences on substance use behavior are not face of challenging life circumstances. only important during adolescence. Studies have shown that alcohol use among adults is likewise influenced by Social Influences on Substance Use peer drinking. College students’ alcohol use was found to be positively correlated with their friends’ alcohol Families use and with the students’ perceptions of their friends’ In addition to genetic factors, addictive behaviors are drinking. Often, college students who drink heavily transmitted between generations in families due to report that their peers drink at the same levels as they social influences. Social Learning Theory posits that do. Interventions for college students in which they are modeling influences behavior, and that adolescents given feedback about how much they are drinking in who observe substance use in their parents are more relation to normative drinking for peers of the same likely to use substances themselves. This assertion is gender and age demonstrate that high-risk drinkers supported in the research literature. However, there is are in fact consuming more alcohol than is normative evidence that modeling is not the only way in which for their peer group. Normative feedback interventions parental influence on adolescent behavior takes place – also demonstrate that heavy drinkers overestimate parents also influence adolescents’ behavior via norms what is normative drinking, such that they erroneously and perceived attitudes. Numerous studies have found believe most students drink as they do. These interven- support for the association between parental approval tions consistently have been shown to result in of substance use and adolescent use of alcohol, tobacco, decreased alcohol consumption and related problems and marijuana – adolescents whose parents have posi- for college students. Other research has found a positive tive attitudes toward substance use are more likely to correlation between alcohol use in adults and their use substances. Among college students, perceptions perceptions of their peers’ alcohol use. Heavy-drinking of parental approval of alcohol consumption were posi- adults report having larger drinking social networks tively associated with experiencing a drinking problem. than do light or moderate drinkers. Social networks Perceived parental approval of illicit drugs was found to are important influences on adult substance use as predict earlier first use of drugs and increased current well as adolescent substance use. Several studies have frequency of drug use. Families also play a protective found support for the assertion that greater alcohol

I. THE NATURE OF ADDICTION PSYCHOSOCIAL FACTORS AND THE DEVELOPMENT OF ADDICTIVE BEHAVIORS 67 involvement among one’s peer network is associated who reported greater drug exposure and use. Also, with heavier drinking among both men and women. ethnic minority students who reported having behavior, This relationship is independent of sociodemographic speech, and looks that are common in their ethnic group and individual difference variables and alcohol reported greater drug exposure and use, whereas White expectancies. students who viewed their behavior, speech, and looks as typical of their ethnic group reported lower exposure Spouses and Intimate Partners and use of drugs. Among Mexican Americans and Among adults, spouses and intimate partners are the American Indians, a stronger sense of ethnic identity most important and influential social connections was associated with decreased substance use. people have. Research has supported spousal concor- Gender dance in substance use behavior – wives and husbands tend to use the same substances, and heavy drinking Across cultures, males smoke more, use more drugs, or drug use in one partner predicts heavy use in the consume more alcohol, and have more alcohol and other other partner. Problem drinkers are disproportionately substance use disorders than females. Gender differ- more likely to be married to other problem drinkers. ences in alcohol consumption may be due to differences Marriage, however, also is a protective factor as it is in availability of alcohol and other substances; they also often associated with a decrease in drinking. may be partially attributable to adherence to traditional gender roles. Females who espouse more traditional Other Individual Difference Variables gender role attitudes drink less than their less conven- that Influence Substance Use tional counterparts, while the opposite holds true for males. Among women, but not men, becoming a parent Ethnicity and Culture also is associated with decreased risk for drinking prob- National surveys have documented racial/ethnic lems. Peer influence on smoking is stronger for females differences in rates of substance use, with certain ethnic than for males. Research has found that females respond minority groups (e.g. African Americans, American more than males to the reinforcing properties of Indians/Alaska Natives) reporting disproportionately substances and may develop drug abuse and depen- high rates of substance use and dependence. There are dence more rapidly than males. Other risk factors for numerous reasons for disparate rates of use and depen- addiction, such as childhood physical and sexual abuse, dence among ethnic minorities, including increased risk depression, intimate partner violence, and posttraumatic factors such as poverty, discrimination, microaggres- stress disorder may play a more important role in the sions, and stress among minority groups. Ethnicity initiation and maintenance of drug use among women also has been shown to moderate the associations than among men. One study found that women’s between the risk factors and substance use. One study tobacco use was more influenced by social factors than found that substance availability and perceived parental physiological dependence when compared with men’s approval differed among Whites, African Americans, tobacco use. Women also report a greater propensity to and Asians, resulting in ethnic differences in substance use substances to alleviate negative affect than men. use initiation and stated intentions to use substances. With regard to cigarette use, White adolescents were Environmental Influences on Substance Use most strongly influenced by adult and peer smoking; for African Americans, however, risk taking was Availability of substances has been shown to be a stronger predictor of smoking behavior than social a major factor in the initiation of substance use and the norms. Among Hispanics, the perception of adult and development of substance use disorders. In order for peer approval of smoking was the strongest predictor a genetic predisposition to result in addictive behavior, of adolescent tobacco use; among Asians, peer and one must interact with the agent of addiction family influence was not as important for the prediction (e.g., alcohol or drugs). Increased availability of alcohol of adolescent smoking as poor academic performance or drugs makes increased contact with substances and low self-esteem. possible. Rates of smoking are increased in areas with Other research has found that ethnic labels and ethnic no smoking area restrictions and are decreased when identity influence substance use. In a study of middle laws prohibiting indoor smoking are enforced. The school students, having a strong sense of ethnic pride prevalence of alcohol use and alcohol use disorders is was protective for African American, Mexican Amer- greater in neighborhoods with more bars and liquor ican, and mixed-ethnicity students, as these students stores, and research suggests that there are more bars reported less exposure to drugs and less drug use and liquor stores in ethnic minority neighborhoods, than those with lower levels of ethnic pride. The oppo- which may account for some ethnic group differences site was true for ethnically proud White students, in rates of alcohol-related problems. Socioeconomic

I. THE NATURE OF ADDICTION 68 6. THE BIOPSYCHOSOCIAL MODEL OF ADDICTION status also affects substance use behavior. Poverty is an circumstances, enhancing social support for sobriety, established risk factor for alcohol and drug problems, and establishing a lifestyle free of substance abuse is and low income is associated with alcohol dependence essential to long-term recovery. Recovery from addiction and comorbid psychiatric disorders. Research on neigh- requires a biopsychosocial approach with attention borhood disorganization, operationalized as high popu- paid to biological, psychological, and social aspects of lation density, physical deterioration, high crime rates, addiction. and the presence of illegal drug trafficking, has found that residing in disorganized neighborhoods strongly Natural Recovery increases the likelihood of adolescent substance use. Social engineering and public policy approaches to According to the biomedical model, addiction is substance-related problems have had some success, a chronically relapsing brain disease that will progress adding further support to the biopsychosocial model unless treated. The biopsychosocial model, on the other of addiction. For example, when alcohol was made hand, recognizes the occurrence of natural recovery. illegal during prohibition, national rates of drinking Natural recovery, or recovery in the absence of profes- and associated health consequences such as cirrhosis sional treatment, is one of the most common methods of the liver were reduced. There also are areas within of recovering from substance abuse problems. Studies the United States (e.g., villages in rural Alaska) where of the reasons for natural recovery have identified alcohol is illegal. For example, the Alaska State Local many precipitants to change, including a meaningful Option Law, implemented in 1981, allowed Alaska religious or spiritual experience, suffering a loss, Native communities to decide whether to permit support from family and friends, a personal injury or drinking and what kind of alcohol control policies to illness, or the substance-related injury or the illness of implement. Research shows that the rates of homicide another person. These reasons are external motivators, and accidental death are lower in communities that aspects of one’s social and cultural environment. In opted to ban the sale and importation of alcohol. Laws recovering from addiction, strategies that support regulating the sale of alcohol and tobacco to persons successful self-change include the establishment of under the minimum age limit have served to decrease social support for sobriety, adoption of new coping skills use of these substances. Between 1970 and 1975, 29 states and stress management techniques, and overall lifestyle lowered the minimum drinking age with negative changes such as changing one’s social network, restruc- effects on public health; rates of adolescent alcohol turing leisure time, and avoiding triggers that cause consumption, alcohol-related injuries, and automobile craving. One research study found that people with fatalities increased during this period. When the higher levels of motivation to change, greater commit- minimum drinking age was later increased, there were ment to change, more frequent and persistent use of reductions in adolescent alcohol consumption, alcohol- coping strategies, and more frequent use of self- related injuries, and automobile fatalities. Raising the reinforcement strategies were more likely to be success- minimum drinking age also resulted in decreased prev- ful in self-change of addictive behaviors. alence of alcohol abuse and dependence in the following years. Research on taxation of alcohol and tobacco Medication supports the use of taxes as a means to decrease alcohol and tobacco use. Among 18–20 year olds, increasing the Medication is the treatment of choice for disease price of alcohol resulted in decreased automobile fatali- under the biomedical model. There are several medica- ties. Such approaches to ameliorating addiction prob- tions that are helpful during substance abuse treatment, lems would not make sense and would not be effective but no medication has been shown to cure or prevent if the biomedical model of addiction was accurate. addiction, as would be expected under the biomedical model. For smoking, nicotine replacement therapies such as the nicotine patch, gum, and nasal spray have THE BIOPSYCHOSOCIAL MODEL been shown to double one’s chances of successfully quit- AND ADDICTION TREATMENT ting. These tools work by gradually reducing the smoker’s dependence on nicotine while extinguishing The most successful addiction treatment programs the smoking behavior, with the goal of slowly tapering incorporate strategies to enhance coping, reduce off the nicotine until one is free of the substance. For craving, manage triggers, and prevent relapse. Some opiate dependence, methadone and buprenorphine programs involve medication, but pharmacotherapy have been shown to be effective at reducing cravings often is not considered an essential part of recovery and avoiding withdrawal symptoms, but these medica- from problems of addiction. Instead, finding ways of tions have side effects and other consequences. People in managing difficult emotions, coping with negative life treatment for alcohol dependence may be prescribed

I. THE NATURE OF ADDICTION SUMMARY 69

Antabuse to classically condition them to develop an Self-efficacy aversion to alcohol, but this is only modestly effective under ideal circumstances. Naltrexone, an optiate Self-efficacy is a cognitive factor that is crucial to receptor agonist, when combined with medical manage- recovery from addiction. In order to refrain from using ment, showed evidence of being equally effective in substances, one needs to believe that he or she is capable treating alcohol dependence as an intervention that of managing difficult situations in other ways. Self- combined elements of several effective behavioral treat- efficacy can be built through experience and exposure ments. Treatment for substance dependence in general to different behavioral options. For example, when may benefit from anxiolytic or antidepressant pharma- a smoker foregoes a cigarette in favor of a brisk walk cotherapy to help manage the negative mood that to manage stress, he or she builds self-efficacy by previously was managed by alcohol or other substance proving to himself or herself that a response other use. Overall, medication can be a helpful adjunct to than smoking is possible for the individual, and that psychosocial treatment, but no medication has stress can be relieved in the absence of cigarette been shown to solve the problem of addiction, and smoking. The greater experience one has with using recovery in the absence of pharmacological treatment coping strategies other than substance use, the greater is common. his or her self-efficacy becomes.

SUMMARY

PSYCHOSOCIAL FACTORS IN THE In summary, there is a great deal of evidence support- TREATMENT OF ADDICTION ing the biopsychosocial model of addiction, which gives weight to biological, psychological, and social factors in Readiness to Change understanding the development and progression of substance use problems. Research supports the role of Of particular relevance to the treatment of addiction biological factors such as genetic predisposition in the is the psychological factor of motivation or readiness development of addictive behaviors. At the same time, to change. Research has found that motivation increases psychological and cognitive factors such as outcome the likelihood that someone will seek out treatment and expectancies, self-efficacy, and readiness to change and complete a treatment program or will be successful in social factors such as family, peer, and intimate partner changing his or her substance use in the absence of influences on substance use are equally important. In formal treatment. Greater motivation at treatment initia- order to prevent and treat addictive behaviors, attention tion also is predictive of better long-term outcomes. must be paid to the biological, psychological, and social According to the Transtheoretical Model, a leading factors that interact to produce and maintain disorders model of behavior change that was developed to explain of addiction. The evidence clearly indicates the impor- how people change addictive behaviors, readiness to tance of factors in all three realms, and successful change is a function of decisional balance, or the cogni- treatment programs will benefit from taking a bio- tive appraisal of the pros and the cons of changing. psychosocial view of the problem of addiction. People who rate the cons of changing their substance use as more salient than the pros of changing report being less motivated to reduce their substance use. SEE ALSO People for whom the pros of changing outweigh the cons of changing their substance use are more Behavioral Economic Factors in Addictive Processes, motivated to change and have greater success in Cognitive Factors in Addictive Processes, Contextual attempts to limit their consumption of substances. Read- Factors in Addiction, Disease Model, Families and iness to change can be impacted by processes of change Addiction, Gender Differences, Interpersonal Factors such as consciousness raising, dramatic relief, and self- and Addictive Disorders, Natural Recovery, Peer Influ- liberation. Motivational interviewing is one therapeutic ences on Addiction, Personality and Addiction style that has been shown to be especially effective Processes, Craving and Expectancies with substance users who are low in motivation to change and to bring about greater readiness to change. The extensive body of literature demonstrating the Glossary impact of readiness to change on subsequent substance Biopsychosocial the influence of biological, psychological (including use provides additional support for the biopsychosocial cognitions, emotions, and behaviors), and social (including culture model over the biomedical/disease model of addictive and environment) factors on the development, maintenance, and behavior. treatment of disease.

I. THE NATURE OF ADDICTION 70 6. THE BIOPSYCHOSOCIAL MODEL OF ADDICTION

Health Belief Model the Health Belief Model is an empirically sup- Engel, G.L., 1997. From biomedical to biopsychosocial: being specific ported theory of health behavior change developed to understand in the human domain. Psychosomatics 38, 521–528. and predict the use of health services. The model posits that health Griffiths, M., 2005. A ‘components’ model of addiction within behaviors are influenced by perceived susceptibility to and a biopsychosocial framework. Journal of Substance Abuse 10, perceived severity of disease, as well as perceived benefits and 191–197. barriers to changing behavior. In recent years, two additional Leonard, K.E., Blane, H.T., 1999. (Eds.) Psychological Theories of constructs (cues to action and self-efficacy) have been incorporated Drinking and Alcoholism. Guilford, New York. in the Health Belief Model to allow for the prediction of more Marlatt, G.A., 1992. Substance abuse: implications of a bio- general health behaviors. psychosocial model for prevention, treatment, and relapse Theory of Reasoned Action/Theory of Planned Behavior the Theory prevention. In: Gabowski, J. (Ed.), Psychopharmacology: Basic of Reasoned Action/Theory of Planned Behavior (TRA/TPB) is Mechanisms and Applied Interventions. American Psychological a combination of two psychological theories of health behavior Association, Washington, DC, pp. 131–162. change developed by Fishbein and Azjen to explain and predict Marlatt, G.A., Baer, J.S., Donovan, D.M., Kivlahan, D.R., 1988. human behavior. The models posit that the most important aspect Addictive behaviors: etiology and treatment. Annual Review of of behavior change is one’s intention to change. The intention Psychology 39, 223–252. comprises a person’s attitude toward the behavior and subjective Newcomb, M., Earleywine, M., 1996. Intrapersonal contributors to norms. Attitudes, in turn, represent a combination of behavioral drug use. American Behavioral Scientist 39, 823–837. beliefs, evaluations of behavioral outcome, normative beliefs, and Shaffer, H.J., LaPlante, D.A., LaBrie, R.A., et al., 2004. Toward the motivation to comply with recommendations. The model has a syndrome model of addiction: multiple expressions, common empirical support and allows for the prediction of human behavior. etiology. Harvard Review of Psychiatry 12, 367–374.

Further Reading Relevant Websites Borrell-Carrio, F., Suchman, A.L., Epstein, R.M., 2004. The biopsychosocial model 25 years later: principles, practice, and scien- http://www.cdc.gov – CDC tiﬁc inquiry. Annals of Family Medicine 2, 576–582. http://www.niaaa.nih.gov – NIAAA Engel, G.L., 1977. The need for a new medical model: a challenge for http://www.nida.nih.gov – NIDA biomedicine. Science 196, 129–136. http://www.nida.nih.gov/nidamed – NIDAMED Engel, G.L., 1980. The clinical application of the biopsychosocial http://www.samhsa.gov – SAMHSA model. American Journal of Psychiatry 137, 535–544. http://en.wikipedia.org – Wikipedia

I. THE NATURE OF ADDICTION