Longer duration of untreated depression was associated with increased depression severity after 2 years, according to the results of a study published in PLoS One.
Taiwanese researchers enrolled participants aged 18 to 65 years with major depressive disorder who had been untreated with antidepressants for ≥4 weeks prior to the study (n=155). Participants received venlafaxine extended-release 75 mg/d and zolpidem during the first 4 weeks; control of medication was then discontinued and the patients were treated as general psychiatric patients. At 2-year follow-up, depression severity in patients who were not receiving pharmacotherapy (n=101) was assessed using the Hamilton Depression Rating Scale.
Both the duration of untreated depression and the depression severity at baseline were associated with the depression severity at 2-year follow-up (P <.05 for both). Duration of untreated depression was also inversely correlated with the percentage improvement in depression severity from baseline (P <.05).
Neither the duration of pharmacotherapy during the 2 years nor the duration of discontinuation of pharmacotherapy during the 2 years were associated with severity or percentage improvement of depression severity from baseline to follow-up.
In regression models, duration of untreated depression and educational years at baseline independently predicted the severity and percentage improvement of depression severity from baseline.
Based on the results, the study authors concluded that “early treatment might be an important factor related to the prognosis of depression… Therefore, [duration of untreated depression] is a valuable index for prediction of the long-term prognosis of depression and should be assessed in clinical practice.”
Hung C-I, Liu C-Y, Yang C-H. Untreated duration predicted the severity of depression at the two-year follow-up point. PLoS One. 2017;12(9):e0185119.