Mental Health Outcomes of a National Cohort of Adults Born with Very Low Birthweight.

Children born with a very low birthweight (VLBW; <1500 g) and/or very preterm (VPT; <32 weeks) are at increased risk of mental health problems, but adult data are inconsistent. We examined the prevalence of a range of mental health disorders in a national cohort of adults born with a VLBW, as well as associations between gestational age and mental health outcomes. All infants born with a VLBW in New Zealand in 1986 were followed prospectively from birth. The 12-month prevalence of mental health outcomes, in addition to substance use and violent/property offending were assessed at a median age of 28 years in this cohort relative to 100 full-term (FT) controls. Outcomes were assessed using structured interview methods. There was a modest increase in the overall rate of mental health problems in VLBW adults compared to controls (ARR 1.33 [95% CI 0.83, 2.12]), reflecting slightly higher rates of anxiety disorders, notably agoraphobia (ARR 2.98 [0.64, 13.85]), social phobia (ARR 1.61 [0.71, 3.65]), and suicidal ideation/attempt (ARR 1.66 [0.45, 6.08]), but not depression (ARR 1.02 [0.57, 1.81]). There were no clear differences in substance use/offending outcomes. VLBW individuals born extremely preterm (<28 weeks) were most vulnerable to later mental health problems relative to controls (overall rate of mental health problems ARR 1.54 [0.86, 2.73]). Effect sizes for any anxiety disorder were also higher for VLBW females than VLBW males compared to same-sex controls. This population-based longitudinal cohort study showed that adults born preterm with a VLBW reported more mental health problems than FT controls; however, this difference was small. Pooled analyses involving larger sample sizes are needed, but findings suggest only modest individual and public health impacts of preterm birth on adult mental health functioning.