This paper draws attention to an important adverse outcome in depressi
on, the occurrence of residual symptoms after partial remission. Among
patients with definite major depression followed every 3 months to re
mission and thereafter, residual symptoms reaching 8 or more on the Ha
milton Depression Scale 17-item total were present in 32% (19) of the
60 who remitted below major depression by 15 months. The pattern was o
f mild but typical depressive symptoms. Residual symptoms were more co
mmon in subjects with more severe initial illness, but were not relate
d to any other predictors, including longer prior illness, dysthymia,
or lower dose of drug treatment during the illness episode. There were
weak associations with personality that might have been consequences
of symptom presence. Residual symptoms were very strong predictors of
subsequent early relapse, which occurred in 76% (13/17) of those with
residual symptoms and 25% (10/40) of those without.