Nearly 50% of individuals in the community meet threshold or subthresh
old diagnostic criteria for depression or anxiety, with depression bei
ng far more common. Co-occurrence of anxiety and depression is common,
as the majority of individuals who experience anxiety also manifest t
hreshold- or subthreshold-level depression. In the current study, addi
tion of subthreshold categories improved the coverage of treated cases
in the community by nearly a third; 61% of subjects were diagnosed ac
cording to threshold criteria while 89% were diagnosed according to su
bthreshold categories. These results suggest that inclusion of subthre
shold-level syndromes enhances the validity of diagnostic systems by i
ncreasing the proportion of treated cases that meet diagnostic criteri
a and by providing a more accurate representation of milder syndromes
of depression and anxiety.