Developmental precursors of affective illness in a general population birth cohort.

Background: Recent evidence suggests that neurodevelopmental impairment may be a risk factor for later affective disorder.

Methods: Associations between childhood developmental characteristics and affective disorder were examined in a prospectively studied national British birth cohort of 5362 individuals born between March 3 and March 9, 1946. Mental state examinations by trained interviewers performed at ages 36 and 43 years identified 270 case subjects with adult affective disorder (AD). Teachers' questionnaires completed at age 13 and 15 years identified 195 case subjects who had shown evidence of childhood affective disturbance (CAD).

Results: Female gender and low educational test scores at ages 8, 11, and 15 years were a risk factor for AD, CAD, and AD without CAD. In addition, attainment of motor milestones was later in the CAD group (odds ratio [OR] = 1.2; 95% confidence interval [CI], 1.1-1.3), followed by, and independent of, greater risk for speech defects between the ages of 6 and 15 years (OR = 2.0; 95% CI, 1.3-3.0), decreased psychomotor alertness on medical examination between ages 4 and 11 years (OR = 4.6; 95% CI, 2.2-9.7), and an excess of twitching and grimacing motor behaviors in adolescence (OR = 3.9; 95% CI, 2.5-6.1). Persistent CAD was strongly associated with persistent AD (OR = 7.8; 95% CI, 2.6-23.2).

Conclusion: The findings give credence to the suggestion that affective disorder, especially its early-onset form, is preceded by impaired neurodevelopment.