“Complicated” subthreshold depression (CsD) is more severe than “uncomplicated” subthreshold depression (UsD) and comparable to mild major depression disorder (MDD), a recent study found. Thus, complicated status more validly indicates depression severity than the standard number-of-symptoms measure. Using nationally representative community data from the National Comorbidity Survey, 7 depression lifetime history subgroups were identified: 1 MDD screener symptom (n=1,432); UsD (n=430); CsD (n=611); uncomplicated MDD (n=182); and complicated MDD with 5 to 6 symptoms (n=518), 7 symptoms (n=217), and 8 to 9 symptoms (n=291). Severity was evaluated using 5 concurrent pathology validators: suicide attempt, interference with life, help seeking, hospitalization, and generalized anxiety disorder. They found:
- CsD validator levels are substantially higher than both UsD and UMDD levels, and similar to mild CMDD, disconfirming the “monotonicity thesis” that severity increases with symptom number.
- Complicated/uncomplicated status predicts severity, and when complicatedness is controlled, number of symptoms no longer predicts validator levels.
Wakefield JC, Schmitz MF. Severity of complicated versus uncomplicated subthreshold depression: New evidence on the “Monotonicity Thesis” from the national comorbidity survey. [Published online ahead of print January 23, 2017]. J Affect Disord. doi:10.1016/j.jad.2017.01.034.