MODULE I: Basic Concepts in Drug Addiction José Pedro Espada Daniel Lloret Irles Module I: Basic Concepts in Drug Addiction Unit 1. How drugs work. 1.1. Drug concept. 1.2. Drug classification. 1.3. Effects of drugs. Unit 2. The state of the matter: How much drug use is there? 2.1. Epidemiology in addictions. 2.2. Prevalence of substance consumption in the school. Unit 3. From use to dependence. Diagnosis. 3.1. Consumption patterns. 3.2. Diagnostic criteria. Unit 4. Individual and social factors that modulate the initiation and maintenance of drug consumption. 4.1. Individual factors. 4.2. Macrosocial factors. 4.3. Microsocial factors. 4.4. Personal factors. 4.5. Integration of consumption risk factors. MODULE 1 BASIC CONCEPTS IN DRUG ADDICTION José Pedro Espada and Daniel Lloret Irles Universidad de Elche SUMMARY Since prehistoric times people have turned to drugs to lessen physical pain or alter their state of consciousness. Drug use was generally limited to people who had reached maturity or very particular situations. Currently, drug use and abuse is a very serious social and public health problem that generates great social concern. This is due to the widespread drug consumption in many sectors of the population, the decline in the age of usage initiation and the severity of the individual and community consequences of the phenomenon on the three levels considered in the current concept of health: physical, psychological and social. If a few years ago, speaking of the drug problem usually alluded to illegal drugs such as heroin, currently the concern has focused on the consumption of legal drugs such as alcohol and tobacco, which are considered the gateway to the consumption of other substances. Alcohol and tobacco are also considered the gateway to the use of substances whose consumption is increasing, cannabis and cocaine. During the last two decades, drug abuse prevention programs have evolved considerably. Pharmacological and psychological treatments have also progressively improved. Nevertheless, preventive and therapeutic action, given the continuous change and complexity of the phenomenon, is still insufficient. This chapter introduces some basic concepts in the addictions field. We review aspects such as the definition of drugs and addictive behavior, consumption patterns and the current status of the problem. Also presented are the criteria used to determine whether consumption or abuse of a substance is taking place. Finally, we review the main individual risk factors that favor substance consumption and integrate them into a comprehensive model. UNIT 1: HOW DRUGS WORK Drug consumption behavior is the same as all other maladaptive behavior: it is the result of a complex interaction of personal and environmental factors. 1 Basic Concepts in Drug Addiction Moreover, in this case, the added difficulty of the effects a given psychoactive substances has on the body must be considered. To understand the magnitude of the phenomenon it is necessary to know the basic physiological correlates of drug consumption. In this first unit general concepts on the pharmacodynamics and pharmacokinetics of drug consumption are addressed. The characteristics of the main psychoactive substances and their psychoactive effects and mechanisms are also presented. 1.1. Drug Concept The World Health Organization (WHO) defines drug as any substance which, introduced into the living organism can modify one or more of its functions . The presence of drugs in many civilizations goes back to time immemorial. Greeks and Romans deified wine with the figures of Dionysus and Bacchus, respectively. Historically, drugs have been linked to magical-religious rituals, celebrations and social events. Gradually their use became widespread in other contexts. Some of these substances are natural in origin, as is the case with tobacco or cannabis. Others are the result of chemical processes carried out using natural products, like what occurs with alcoholic beverages, which are obtained from the fermentation or distillation of grain or fruit juice. Drugs are also produced artificially. This is the case for drugs for psychiatric use or for synthetic drugs. 1.2. Drug Classification Several criteria have been used when classifying drugs. Based on compliance with laws, drugs are classified as legal (e.g., alcohol, tobacco, coffee, hypnotics, sedatives, inhalants, etc.) and illegal (e.g., opiates cannabis, cocaine, synthetic drugs, hallucinogens, etc.). There has also been a differentiation between soft and hard drugs, although currently that distinction is rarely used because of its scant utility and the fact that it can give rise to the erroneous interpretation that so-called soft drugs are not quite detrimental to health. Another classification criterion is based on the effect produced in the central nervous system (CNS). Thus, Chalout (1971) proposed a typology that distinguishes between drugs that are depressants, stimulants and perturbers of the CNS. Table 1 provides a complete account based on this criterion. The first group includes alcohol, opiates and psychotropic drugs such as hypnotics, anxiolytics and antipsychotics. Among the second group are major alertness stimulants (e.g., amphetamines and cocaine) and minor alertness stimulants (e.g., caffeine and nicotine), and mood 2 José Pedro Espada and Daniel Lloret Irles boosters (antidepressants). In the third group, consisting of psychedelic drugs, are hallucinogens, cannabis, synthetic drugs and solvents (e.g., glues, adhesives, etc.). Table 1. Classification of drugs according to their main effects 1. Central Nervous System Depressants a) Alcohol b) Hypnotics: Barbiturates and non-barbiturates c) Anxiolytics: diazepam d) Narcotic analgesics: i. Opium and derivatives: Heroin, morphine, codeine, etc. ii. Synthetic narcotics: methadone, etc. e) Antipsychotics (major tranquilizers) 2. Central Nervous System Stimulants a) Alertness stimulants. i. Major: amphetamines, cocaine ii. Minor: nicotine, xanthenes (coffee, tea, cocoa, etc.) b) Mood Boosters: antidepressants 3. Central Nervous System Perturbants (psychedelic) a) Hallucinogens: mescaline, LSD, etc. b) Derivatives of cannabis: marijuana, hashish c) Volatile solvents: glue, etc. d) Designer drugs: MDA, MDMA, etc. 3 Basic Concepts in Drug Addiction The definition of drug and addictive behavior is related to other basic terms. The first involves distinguishing between the use and abuse of a substance. We understand drug use to be drug consumption that does not negatively impact health. Drug consumption becomes abusive at the appearance of dependence, which is defined as the set of physiological, behavioral and cognitive manifestations in which the use of a drug is a priority for the individual. This term is usually linked to tolerance , or the need to consume more of a substance to achieve the effects of previous consumption. When a dependent person does not consume, withdrawal syndrome appears. It is a cluster of symptoms that affect an individual who is suddenly deprived of any toxin or drug on which he/she is physically dependent and which previously had been consumed on a regular basis. The quantity of symptoms, as well as their intensity and duration will depend on the type of drug, the length of time the person has consumed the substance and his/her physical and psychological state at the time of withdrawal. Physical dependence is a state of adaptation of the organism to the presence of the drug and is manifested by the appearance of intense physical discomfort (tremors, chills, insomnia, vomiting, pain in the muscles and bones, etc.) when consumption of the substance is stopped. This same physical discomfort occurs when the substance´s action on the organism is influenced by drugs designed to block its effects. Psychological dependence refers to the situation in which a person feels an emotional need and urge to consume a drug on a regular basis in order to feel good, be satisfied (obtain pleasure or avoid discomfort) although he/she does not need the substance physiologically. This may be associated with different contexts or social interactions. Addictions go beyond substance use. There are the so-called non-toxic addictions which involve dependency behavior with an evident syndrome of psychological withdrawal. There is, for example, addiction to gambling or pathological gambling and others such as technological addictions (internet, mobile, and video games), addiction to shopping, exercise or sex. These addictive behaviors share, if not all, some of the characteristics mentioned so far, with the peculiarity that there is not a mediating substance that produces physical changes in the subject. 1.3. Effects of Drugs 4 José Pedro Espada and Daniel Lloret Irles As already mentioned, drugs act on the central nervous system (i.e., they affect the individual's neurological functioning). The physiological correlates and effects vary according to each substance; there are specific mechanisms that involve precise receptors for each substance type. In this section we present some common aspects to the physiological effects of drugs. When a substance enters the body it first affects the neuronal receptors, which are structures located within a neuron or in its membrane and are characterized by selective binding to a substance and the physiological effect that accompanies the union. The presence of a drug in the body affects the presynapse, altering the production/ release of neurotransmitters. During the next step, the drug affects the synapses, by