Context: Little is known about the mental health outcomes of very low-birth-weight (VLBW) (< 1500 g) infants in young adulthood.
Objective: To test whether young adults aged 18 to 27 years with VLBW differ from term control subjects in depressive symptoms, current use of antidepressant medication, and the rate of depression diagnosed by a physician.
Design: Retrospective longitudinal study.
Setting: Academic research.
Participants: A total of 162 VLBW young adults (response rate, 65.1%) and 172 term control subjects (response rate, 54.8%) born between February 22, 1978, and November 8, 1985, in Helsinki, Finland.
Main outcome measures: Antidepressant use, history of physician-diagnosed depression, Beck Depression Inventory score, and Center for Epidemiologic Studies Depression Scale score.
Results: The VLBW participants reported 20.1% (95% confidence interval [CI], -40.8% to -5.1%) lower CES-D scores than the controls (P =.02). However, this finding was confined to 110 VLBW participants who were born appropriate for gestational age (birth weight > or = -2 SDs according to Finnish birth weight charts), whose Center for Epidemiologic Studies Depression Scale scores were 29.1% (95% CI, -53.7% to -8.4%) lower than those of the controls (P =.004). Furthermore, VLBW participants born appropriate for gestational age were 4.8 (95% CI, 1.3-10.0) times less likely to report a depression diagnosis than controls (P =.02). In contrast, 52 VLBW participants born small for gestational age (birth weight < -2 SDs according to Finnish birth weight charts) reported 36.2% (95% CI, 1.1%-83.5%) higher Beck Depression Inventory scores (P =.04), were 4.0 (95% CI, 1.1-14.3) times more likely to use antidepressants (P =.03), and were 2.5 (95% CI, 1.0-6.3) times more likely to report a depression diagnosis (P =.04) compared with controls.
Conclusions: This is the first study (to our knowledge) to show that intrauterine growth pattern may modify associations between VLBW and depression. Intrauterine growth retardation rather than VLBW per se may pose a risk of depression in young adulthood.