Subclinical suspiciousness as a risk factor for depressive episodes

Previous studies suggest suspiciousness is associated with an increased risk of major depressive episodes in psychotic patients. We tested the hypothesis that this relationship would extend to nonpsychotic groups.

Data came from the Epidemiological Catchment Area (ECA) study, a longitudinal population-based study conducted at five sites in the United States. Baseline clinical and demographic features were used to predict the onset of episodes of depression at 1-year follow-up in subjects without psychotic symptoms.

Subclinical suspiciousness was associated with an increased risk of new episodes of depression after accounting for demographic variables. However, three of six subclinical delusion-like experiences were also associated with an increased risk of depressive episodes. None of the subclinical hallucination-like experiences predicted subsequent risk.

Subclinical suspiciousness appears to increase the risk of depression in the general population. Some other delusion-like experiences may do the same.