Smokin' hot: adolescent smoking and the risk of psychosis.

OBJECTIVE: Daily smoking has been associated with a greater risk of psychosis. However, we are still lacking studies to adjust for baseline psychotic experiences and other substance use. We examined associations between daily smoking and psychosis risk in a 15-year follow-up while accounting for these covariates in a prospective sample (N = 6081) from the Northern Finland Birth Cohort 1986. METHODS: Self-report questionnaires on psychotic experiences (PROD-screen), tobacco smoking and other substance use were completed when the cohort members were 15-16 years old. Tobacco smoking was categorized into three groups (non-smokers, 1-9 cigarettes and ≥10 cigarettes/day). Psychosis diagnoses were obtained from national registers until the age of 30 years. RESULTS: Subjects in heaviest smoking category were at increased risk of subsequent psychosis (unadjusted HR = 3.15; 95% CI 1.94-5.13). When adjusted for baseline psychotic experiences the association persisted (HR = 2.87; 1.76-4.68) and remained significant even after adjustments for multiple known risk factors such as cannabis use, frequent alcohol use, other illicit substance use, parental substance abuse, and psychosis. Furthermore, number of smoked cigarettes increased psychosis risk in a dose-response manner (adjusted OR = 1.05; 1.01-1.08). CONCLUSION: Heavy tobacco smoking in adolescence was associated with a greater risk for psychosis even after adjustment for confounders.

Serious delinquency and later schizophrenia: A nationwide register-based follow-up study of Finnish pretrial 15- to 19-year-old offenders sent for a forensic psychiatric examination.

BACKGROUND: Aggressive and disruptive behaviors often precede the onset of schizophrenia. In this register-based follow-up study with a case-control design, we wanted to investigate if serious delinquency was associated with future diagnoses of schizophrenia or schizoaffective disorder (here, broadly defined schizophrenia) among a nationwide consecutive sample of 15- to 19-year-old Finnish delinquents sent for a forensic psychiatric examination in 1989-2010. METHODS: The sample comprised 313 delinquents with no past or current psychotic disorder. For each delinquent, four age-, gender- and place of birth -matched controls were randomly selected from the Central Population Register. Five controls (0.4%) had been treated for schizophrenia before their respective index-dates and were thus excluded from further analysis, leaving us with a control population of 1247 individuals. The subjects were followed till death, emigration or the end of 2015, whichever occurred first. Diagnoses were obtained from the Care Register for Health Care. RESULTS: Forty (12.8%) of the delinquents and 11 (0.9%) of the controls were diagnosed with schizophrenia later in life (HR 16.6, 95% CI 8.53-32.39, P<0.001). Almost half of the pretrial adolescents with later schizophrenia were diagnosed within 5years of the forensic psychiatric examination, but latency was longer among the other half of the sample, reaching up to 20.5years. CONCLUSIONS: The study supports the previous research indicating a potential link between serious delinquency and later schizophrenia. Accurate psychiatric assessments should be made in correctional services but also later in life so that any possible psychotic symptoms can be detected in individuals with a history of serious delinquency even if there were no signs of psychosis before or at the time of the crime. Future research should explore which factors influence the delinquent's risk of developing later schizophrenia.