Background: With psychopathology rising during adolescence and evidence suggesting that adult mental health burden is often due to disorders beginning in youth, it is important to investigate the epidemiology of adolescent mental disorders.Method: We analysed data gathered at ages 11 (baseline) and 19 years from the population-based Dutch TRacking Adolescents' Individual Lives Survey (TRAILS) study. At baseline we administered the Achenbach measures (Child Behavior Checklist, Youth Self-Report) and at age 19 years the World Health Organization's Composite International Diagnostic Interview version 3.0 (CIDI 3.0) to 1584 youths.Results: Lifetime, 12-month and 30-day prevalences of any CIDI-DSM-IV disorder were 45, 31 and 15%, respectively. Half were severe. Anxiety disorders were the most common but the least severe whereas mood and behaviour disorders were less prevalent but more severe. Disorders persisted, mostly by recurrence in mood disorders and chronicity in anxiety disorders. Median onset age varied substantially across disorders. Having one disorder increased subjects' risk of developing another disorder. We found substantial homotypic and heterotypic continuity. Baseline problems predicted the development of diagnosable disorders in adolescence. Non-intact families and low maternal education predicted externalizing disorders. Most morbidity concentrated in 5–10% of the sample, experiencing 34–55% of all severe lifetime disorders.Conclusions: At late adolescence, 22% of youths have experienced a severe episode and 23% only mild episodes. This psychopathology is rather persistent, mostly due to recurrence, showing both monotypic and heterotypic continuity, with family context affecting particularly externalizing disorders. High problem levels at age 11 years are modest precursors of incident adolescent disorders. The burden of mental illness concentrates in 5–10% of the adolescent population.

OBJECTIVE This paper examines whether equal utilisation of health care services for first generation immigrant groups has been achieved in the Netherlands. DESIGN Survey data were linked to an insurance register concerning people aged 16–64. Ethnic differences in the use of a broad range of health care services were examined in this group, with and without adjustment for health status and socioeconomic status, using logistic regression. SETTING Publicly insured population in Amsterdam, the Netherlands. PARTICIPANTS 1422 people from the indigenous population, and 378 people from the four largest immigrant groups in the Netherlands—that is, the Surinamese, the Netherlands Antilleans, and the Turkish and Moroccan. MAIN OUTCOME MEASURES General practitioner service use (past two months), prescription drug use (past three months), outpatient specialist contact (past two months), hospital admission (past year), physiotherapist contact (past two months) and contact with other paramedics (past year). MAIN RESULTS Ethnicity was found to be associated with the use of health care after controlling for health status as an indicator for need. The use of general practitioner care and the use of prescribed drugs was increased among people from Surinam, Turkey and Morocco as compared with the indigenous population. Compared with the indigenous group with corresponding health status, the use of all other more specialised services was relatively low among Turkish and Moroccan people. Among the Surinamese population, the use of more specialised care was highly similar to that found in the Dutch population after differences in need were controlled for. Among people from the Netherlands Antilles, we observed a relatively high use of hospital services in combination with underuse of general practitioner services. The lower socioeconomic status of immigrant groups explained most of the increased use of the general practitioner and prescribed drugs, but could not account for the lower use of the more specialised services. CONCLUSIONS The results indicate that the utilisation of more specialised health care is lower for immigrant groups in the Netherlands, particularly for Turkish and Moroccan people and to a lesser extent, people from the Netherlands Antilles. Although underuse of more specialised services is also present among the lower socioeconomic groups in the Netherlands, the analyses indicate that this only partly explains the lower utilisation of these services among immigrant groups. This suggests that ethnic background in itself may account for patterns of consumption, potentially because of limited access.

TRAILS consists of a population cohort (N = 2230) and a clinical cohort (N = 543), both of which were followed from about age 11 years onwards. To date, the population cohort has been assessed five times over a period of 11 years, with retention rates ranging between 80% and 96%. The clinical cohort has been assessed four times over a period of 8 years, with retention rates ranging between 77% and 85%. Since the IJE published a cohort profile on the TRAILS in 2008, the participants have matured from adolescents into young adults. The focus shifted from parents and school to entry into the labour market and family formation, including offspring. Furthermore, psychiatric diagnostic interviews were administered, the database was linked to a Psychiatric Case Registry, and the availability of genome-wide SNP variations opened the door to genome-wide association studies regarding a wide range of (endo)phenotypes. With some delay, TRAILS data are available to researchers outside the TRAILS consortium without costs; access can be obtained by submitting a publication proposal (see www.trails.nl).