Can the DSM's major depression bereavement exclusion be validly extended to other stressors?: Evidence from the NCS
Jerome C. Wakefield, PhD, DSW, Silver School of Social Work, New York University, 1 Washington Square North, New York, NY 10003, USA.
To evaluate whether the DSM's distinction between uncomplicated (normal) vs. complicated (disordered) bereavement-related depressive episodes can be validly extended to non-bereavement stressor-related depression (SRD). Previous findings supporting the uncomplicated/complicated SRD distinction's discriminant validity were criticized as tautological because of definitional biases (e.g., ‘uncomplicated’ requires brief duration, yet duration was a validator). We tested whether uncomplicated/complicated SRD validator differences are tautological or real.
Using National Comorbidity Survey data, we compared uncomplicated SRDs, complicated SRDs, and endogenous/psychotic MDD on levels of eight pathology validators. We identified definitional biases affecting six validators, and corrected them by deleting the biasing definitional components and recalculating validator levels.
After correction of biases, uncomplicated SRDs had significantly lower pathology levels than both complicated SRDs and endogenous/psychotic MDD on seven of eight validators, disconfirming the tautology hypothesis. Regression analysis revealed that ‘uncomplicated’ cannot be equated with ‘mild’. Extending the ‘uncomplicated’ durational threshold from 2 to 6 months yielded equal or stronger discriminant validity, suggesting the arbitrariness of the current durational criterion.
Uncomplicated SRDs' lower pathology levels are because of real syndromal differences, not definitional tautologies. The uncomplicated/complicated distinction has discriminant validity when extended to non-bereavement SRDs as an indicator of normality vs. disorder.