Our study examined whether the early-onset depression phenotype among young adults
(probands) is associated with the metabolic syndrome (MetS) and its components, and
if MetS characterizes unaffected but high-risk siblings of probands.We studied three
groups of young adults (Mage = 25 years, s.d. = 3.84 years): probands with histories
of childhood onset depression - i.e. early-onset phenotype - (n = 293), their unaffected
siblings (high-risk siblings, n = 273), and healthy controls (n = 171). Participants
completed a full psychiatric interview, physical and laboratory assessments, and self-rating
scales. MetS was defined using the criteria of the Expert Panel on Detection, Evaluation,
and Treatment of High Blood Cholesterol in Adults (2001).Early-onset depression phenotype
and being a high-risk sibling were associated with higher MetS composite scores relative
to that of controls, but did not differ from one another. With regard to MetS components:
Probands and siblings had similarly larger waist circumference and lower HDL than
did controls, while siblings and controls had lower triglyceride levels than did probands
but did not differ from one another. Groups did not differ on glucose levels and SBP.Our
study extends the literature on the association between MetS and depression and underscores
the importance of depression phenotypes: failure to account for the clinical heterogeneity
of depression may partly underlie the inconsistent findings regarding its relation
to MetS. The results also suggest that, in depression-prone populations, MetS may
predate and possibly function as a risk factor for eventual depression.