Background. Many social and demographic correlates of psychiatric diso
rder have shown marked secular changes in recent decades. This study w
as designed to explore some of the implications of these trends, focus
ing on the illustrative case of teenage motherhood. Method. Prospectiv
e data from two British birth cohort studies (the 1946 and 1958 cohort
s) were used to examine the social, educational and behavioural precur
sors of teenage versus older age at motherhood, and the implications o
f teenage motherhood for women's later marital and social circumstance
s and risks of psychiatric morbidity, in samples born 12 years apart.
Results. Educational and social disadvantage were associated with simi
larly increased risks of teenage motherhood in both cohorts, but the f
indings suggested an additional association with teacher-rated adolesc
ent conduct problems in the more recent sample. Rates of teacher-rated
emotional problems were not elevated among teenage mothers in either
cohort. In adult life, teenage motherhood was associated with a range
of adverse social outcomes, including partnership breakdowns, large fa
mily size, and poorer housing conditions. Relative risks of these adul
t adversities were similar for teenage mothers in the two cohorts, but
absolute levels of adversity were higher in the more recent sample, r
eflecting general secular changes in many of the indicators involved.
In the later, but not the earlier, cohort, teenage motherhood was also
associated with increased risks for psychiatric morbidity in adulthoo
d. Conclusions. The findings underline the importance of taking accoun
t of secular trends in examining the impact of psychosocial risks.