Objective: The authors' goal was to evaluate the association between impairment in daily function and subsyndromal depressive symptoms as well as major depression to determine the economic and societal significance of these conditions.
Method: Using 12-month prevalence data gathered by the National Institute of Mental Health (NIMH) Epidemiologic Catchment Area Program (ECA), based on responses to the NIMH Diagnostic Interview Schedule, the authors divided the 2,393 subjects from the Los Angeles ECA site into three groups: subjects with subsyndromal depressive symptoms (N = 270), major depression (N = 102), and no depressive disorder or symptoms (N = 2,021). The groups were compared on 10 domains of functional outcome and well-being.
Results: Significantly more subjects with depressive symptoms than subjects who had no disorder reported high levels of household strain, social irritability, and financial strain as well as limitations in physical or job functioning, restricted activity days, bed days, and poor health status. Significantly more subjects with major depression than subjects with no disorder reported major financial losses, bed days, high levels of financial strain, limitations in physical or job functioning, and poor health status. Except for lower self-ratings of health status, no significant differences were found between subjects with subsyndromal symptoms and those with major depression.
Conclusions: Significantly more people with subsyndromal depressive symptoms or major depression reported impairment in eight of 10 functional domains than did subjects with no disorder. The high 1-year prevalence of subsyndromal depressive symptoms, combined with the associated functional impairment, emphasizes the clinical and public health importance and need for additional investigations into these symptoms.