Introduction: Advanced paternal age (APA) is a reported risk factor for schizophrenia in the offspring. We performed a meta-analysis of this association, considering the effect of gender and study design. Methods: We identified articles by searching Pub Med, PsychInfo, ISI, and EMBASE, and the reference lists of identified studies. Previously unpublished data from the Northern Finland 1966 Birth Cohort (NFBC 1966) study were also included. Results: There were 6 cohort studies and 6 case–control studies that met the inclusion criteria. In both study designs, there was a significant increase in risk of schizophrenia in the offspring of older fathers (≥30) compared to a reference paternal age of 25–29, with no gender differences. The relative risk (RR) in the oldest fathers (≥50) was 1.66 [95% confidence interval (95% CI): 1.46–1.89, P < 0.01]. A significant increase in risk was also found for younger fathers (<25) in males (RR = 1.08, 95% CI: 1.02–1.14, P = 0.01) but not females (RR = 1.04, 95% CI: 0.97–1.14, P = 0.28). The population attributable risk percentage (PAR%) was 10% for paternal age ≥30 and 5% for paternal age <25. Discussion: Both APA (≥30) and younger paternal age (<25) increase the risk of schizophrenia; younger paternal age may be associated with an increased risk in males but not females. This risk factor increases the risk of schizophrenia as much as any single candidate gene of risk. The mechanism of these associations is not known and may differ for older and younger fathers.

Suicide in the adolescent population is a tragic and preventable cause of death. Previous studies have confirmed both long and short total sleep times (TSTs) are associated with suicidal ideation in the adult population. We hypothesized that both long and short TSTs are risk factors for serious suicide attempt in the adolescent population as well. We tested this hypothesis using the Youth Risk Behavior Surveys from 2007 and 2009, which consist of school-based, nationally representative samples (N = 12,154 for 2007, N = 14,782 for 2009). Logistic regression models were used to assess the relationship between suicidality and sleep after adjusting for confounders including age, sex, race/ethnicity, feelings of sadness, and substance abuse. Of the total sample, roughly 15% reported suicidal ideation, 10% planned suicide, 5% attempted and 2% reported an attempt requiring treatment. Teens who reported sleeping ≤ 5 or ≥ 10 h had a significantly higher risk for suicidality compared to those with a TST of 8 h. The largest odds ratios were found among the most severe forms of suicidality (attempt requiring treatment) with an odds ratio of 5.9 for a TST ≤ 4 h and 4.7 for a TST ≥ 10 h. Both short and long TSTs are risk factors for suicidality among teens and extremes in TST may indicate more serious suicidality. Self-reported sleep duration may be a useful screening question for suicide risk. Future studies should examine whether sleep duration is a causal and/or modifiable risk factor for suicidality in teens.