Early-onset and recurrent depression in parents increases risk of intergenerational transmission to adolescent offspring.

BACKGROUND: To assess whether the age-of-onset or the recurrence of parents' major depressive disorder (MDD), measured prospectively in a longitudinal birth cohort study, predicted offspring depression at age 15. METHODS: A two-generation study of New Zealanders, with prospective, longitudinal data in the parents' generation (n = 375) and cross-sectional data from their adolescent offspring (n = 612). Parent and offspring depression was measured with structured clinical interviews. Parent depression was measured at six time points from age 11 to 38 years. Adolescent offspring depression was measured at age 15. RESULTS: Compared to adolescents whose parents were never depressed, those whose parents met criteria for MDD more than once and those whose parents first met criteria before adulthood had more symptoms of depression. The combination of early-onset and recurrent depression in parents made adolescents particularly vulnerable; their odds of meeting criteria for MDD were 4.21 times greater (95% CI = 1.57-11.26) than adolescents whose parents were never depressed. The strength of the intergenerational effect did not vary as a function of parent or offspring sex. The prevalence of adolescent depression was 2.5 times higher in the offspring than at age 15 in the parents' generation. CONCLUSIONS: Recurrent depression in both fathers and mothers increases offspring risk for depression, particularly when it starts in childhood or adolescence, but a single lifetime episode does not. Health practitioners should be aware of age-of-onset and course of depression in both parents when assessing their children's risk for depression.

Impact of New Zealand teenagers' fertility intentions on childbearing.

Objective: To assess the impact of age 15 fertility intentions on childbearing outcomes three decades later. Background: Evidence is mixed about the implications of teenage fertility intentions on later childbearing. Taking a prospective life course approach to assessing intentions and outcomes may help clarify these mixed findings. Method: A general population birth cohort (born 1972/73) was asked about their fertility intentions at age 15 and 775 of this sample (384 women, 391 men) provided data on their childbearing between ages 15 and 45. Results: At age 15, almost all of the sample indicated they would like to have children in the future (93%). Most (79%) reported having had a biological child by they time they were 45; but those who professed to not wanting children as teenagers were significantly less likely to have had a child three decades later. Conclusion: Fertility intentions during adolescence are probably influenced by social, political and economic norms and may influence later childbearing decisions. This may be particularly true for those whose intentions counter established norms around childbearing. Implications: A life course framework is useful for examining the relationship between hypothetical fertility intentions and outcomes.

Intergenerational changes in adolescents' physical fitness and weight in New Zealand.

AIMS: This research examines fitness and body weight in two cohorts of adolescents, to determine continuity and changes in these measures across two generations. METHODS: Height, weight and fitness were measured in a population-based cohort of 15 year-olds in 1986/7 (Dunedin Study, n=968). The same measures were obtained for their 15-16 year-old children between 2007 and 2015 (Next Generation Study, n=343). Fitness was defined as maximal aerobic capacity (V'O2max). Height and weight were measured in all participants and fitness was adjusted for weight (V'O2max/kg). RESULTS: The Next Generation participants were, on average, heavier than the Dunedin Study participants had been, and had higher body mass index values (kg/m2). Unadjusted V'O2max values for boys did not differ between generations, but were lower in Next Generation girls compared to Dunedin Study girls. For both sexes, the Next Generation participants had lower weight-adjusted V'O2max values than the Dunedin Study participants. Compared to their parents, weight-adjusted V'O2max values were approximately 25% lower in girls and 15% lower in boys. CONCLUSIONS: Overall adolescents today appear to be less fit and heavier than their parents were at the same age. The decline in fitness over a generation is particularly evident in adolescent girls, although boys also have lower levels of fitness once body weight has been taken into account.