Article Prevalence of Depressive Episodes With Psychotic Features in the General Population Maurice M. Ohayon, M.D., D.Sc., Objective: The study evaluated the prev- or guilt were also associated with high Ph.D. alence of major depressive episodes with rates of hallucinations (9.7%) and combi- psychotic features in the general popula- nations of hallucinations and delusions tion and sought to determine which de- (4.5%). The current prevalence of major Alan F. Schatzberg, M.D., Ph.D. pressive symptoms are most frequently depressive episode with psychotic fea- associated with psychotic features. tures was 0.4% (95% CI=0.35%–0.54%), Method: The sample was composed of and the prevalence of a current major de- 18,980 subjects aged 15–100 years who pressive episode without psychotic fea- were representative of the general popu- tures was 2.0% (95% CI=1.9%–2.1%), with lations of the United Kingdom, Germany, higher rates in women than in men. In all, Italy, Portugal, and Spain. The partici- 18.5% of the subjects who fulfilled the cri- pants were interviewed by telephone by teria for a major depressive episode had using the Sleep-EVAL system. The ques- psychotic features. Past consultations for tionnaire included a series of questions treatment of depression were more com- about depressive disorders, delusions, mon in depressed subjects with psychotic and hallucinations. features than in depressed subjects with no psychotic features. Results: Overall, 16.5% of the sample re- ported at least one depressive symptom Conclusions: Major depressive episodes at the time of the interview. Among these with psychotic features are relatively subjects, 12.5% had either delusions or frequent in the general population, af- hallucinations. More than 10% of the sub- fecting four of 1,000 individuals. Feelings jects who reported feelings of worthless- of worthlessness or guilt can be a good ness or guilt and suicidal thoughts also indicator of the presence of psychotic had delusions. Feelings of worthlessness features. (Am J Psychiatry 2002; 159:1855–1861) Depression is the most common mental disease and chotic features reported that the delusional patients were is the second leading cause of disability in Europe and the younger, more frequently had a past history of delusions, United States after heart diseases. Estimates of the previ- and more frequently had feelings of worthlessness (13). ous-year prevalence of major depressive disorders in the Another study did not find differences between psychotic general population have varied between 2.1% and 7.6%, and nonpsychotic depressed subjects in their clinical fea- and estimates of the previous-month prevalence have var- tures (age at onset, duration of the episode, frequency) ied between 1.5% and 6%, depending on the country stud- (14). In this study we report the prevalence of DSM-IV ma- ied and the classification system used (DSM-III, DSM-III- jor depressive episodes with and without psychotic fea- R, DSM-IV, or ICD-10) (1–8). However, these studies lim- tures in the general population of five Western European ited their analyses to broad diagnostic categories (major countries. We evaluated which depressive symptoms were depressive disorder and dysthymia) without describing more likely to be associated with psychotic features in the specifiers of the major depressive disorder. One study general population and the relative contributions of age, found that the lifetime prevalence of psychotic symptoms gender, and chronicity to the prevalence of major depres- in subjects who had ever met the criteria for major depres- sive episode with or without psychotic features. sion was 14% (0.6% lifetime prevalence of major depres- sive episode with psychotic features) (9). However, there Method are generally few data about the prevalence of associated psychotic features in subjects with major depressive disor- Sampling ders in the general population. A number of studies have The participants in the five countries were interviewed by tele- reported that psychotic depression differs from nonpsy- phone between 1994 and 1999 with the broader purpose of inves- tigating sleep habits, sleep-related symptoms, and psychiatric chotic depression in several respects (10–13). A clinical and sleep disorders (15). The United Kingdom, with approxi- study comparing patients with DSM-III-R major depres- mately 46 million inhabitants age 15 years or older, was the first sive disorder with psychotic features to those without psy- country to be studied in 1994. Germany, with 66 million inhabit- Am J Psychiatry 159:11, November 2002 1855 DEPRESSIVE EPISODES WITH PSYCHOTIC FEATURES ants age 15 years or older, was studied next in 1996; then Italy in occurrence of two diagnoses in accordance with the International 1997, with 46 million inhabitants 15 years or older; Portugal in Classification of Sleep Disorders and DSM-IV criteria. The inter- 1998, with 8 million inhabitants 18 years or older; and Spain in view ended once all diagnostic possibilities were exhausted. 1999, with 38.5 million inhabitants 15 years or older. (The mini- The system has been tested in various contexts; in clinical psy- mum age for Portugal was set at 18 years on the recommendation chiatry, overall agreement between the diagnoses of four psychia- of the ethics committee for the Portuguese survey.) The study was trists and those of the system ranged from 0.44 (kappa) with one approved by the ethical and research committee at the Canadian psychiatrist to 0.78 (kappa) with two psychiatrists (N=114 cases) university where the principal investigator (M.M.O.) was located (20). In another study that involved 91 forensic patients, most of at the time of the research and by ethics committees in each of the the patients (60%) met the criteria for a diagnosis in the psychosis countries where the surveys were conducted. The surveys were spectrum. The agreement between diagnoses obtained by the conducted with the help of the Teleperformance Group, a poll system and those given by psychiatrists was 0.44 (kappa) for spe- service company with several affiliates in Europe (British Poll Ser- cific psychotic disorders (mainly schizophrenia). Validation stud- vice [United Kingdom study], Teleperformance [German study], ies performed in sleep disorders clinics (Stanford University, Uni- Grandi Numeri [Italian and Spanish studies], and the poll com- versity of Regensburg, and Toronto Hospital) that tested the pany Action [Portugal]). All surveys were conducted under the su- diagnoses of the system against those of sleep specialists who pervision of the principal investigator (M.M.O.). used polysomnographic data gave kappas between 0.71 and 0.93 The target population was all noninstitutionalized residents for different sleep disorders (21, 22). age 15 years or older (or 18 years or older for Portugal). The same The duration of the interviews ranged from 10 to 333 minutes, two-stage sampling strategy was used for all five countries. In the with an average of 40 minutes (SD=20 minutes). The longest in- first stage, the population was divided by geographical distribu- terviews involved subjects with multiple sleep and mental disor- tion according to the official census data for each country, and ders. Interviews were completed over two or more sessions if the then telephone numbers were randomly drawn. In the second duration exceeded 60 minutes. stage, within each sampled household a member was selected as a function of age and gender by using the Kish method (16) to Variables maintain the representativeness of the sample and to avoid bias The exploration of depression began with questions assessing related to noncoverage error. whether the subject 1) was feeling sad, downcast, or depressed; Participants had to first grant their verbal consent before pro- 2) was feeling hopeless; and 3) had lost interest or lacked pleasure ceeding with the interview. For subjects younger than 18 years of in activities formerly considered pleasant. The subjects were age, the verbal consent of the parents was also requested. We ex- asked to rate these symptoms on an intensity scale (extremely, a cluded potential participants who had insufficient fluency in the lot, moderately, slightly, not at all, does not know) and asked national language, who had a hearing or speech impairment, or whether each symptom was present most of the day and nearly who had an illness that made an interview infeasible. every day. Subjects who answered positively to one of these The participation rate was 79.6% (4,972 of 6,249 eligible individ- symptoms were asked another series of questions that assessed uals) in the United Kingdom; 68.1% (4,115 of 6,047 eligible individ- 1) changes in appetite or weight; 2) insomnia or hypersomnia uals) in Germany; 89.4% (3,970 of 4,442 eligible individuals) in It- symptoms; 3) psychomotor agitation or retardation; 4) fatigue or aly; 83.1% (1,858 of 2,234 eligible subjects) in Portugal; and 87.5% loss of energy; 5) feelings of worthlessness or guilt; 6) difficulties (4,065 of 4,648 eligible individuals) in Spain. Overall, 18,980 sub- in concentration or thinking and difficulties making decisions; jects participated in the study. The overall participation rate was and 7) suicidal ideation. These symptoms were rated by the sub- 80.4%. This sample was representative of 205,890,882 inhabitants. jects on the same intensity scale that was used for the initial symptoms, and the subjects were asked whether the symptom Instrument was present most of the day and nearly every day. The subjects The Sleep-EVAL expert system (17, 18), software developed by also reported how long they had experienced depressive mood. the principal investigator (M.M.O.) to conduct epidemiological The subjects were also asked about current and past use of an- studies in the general population and to administer question- tidepressant medication and whether they were currently con- naires, was used to perform the interviews.