Preonset Predictors of Chronic-Intermittent Depression From Early Adolescence to Early Adulthood

Individuals with prolonged or frequent episodes account for a disproportionate share of the burden of depression. However, there are surprisingly few data on whether individuals at risk for developing chronic-intermittent depression (CID) as opposed to briefer, infrequent depressive episodes (time-limited depression [TLD]) can be distinguished before their first depressive episode. We followed a community sample of 465 never-depressed females on five occasions from age 14 to 20 years and examined whether 18 preonset clinical and psychosocial variables prospectively predicted CID. The CID group accounted for 40% of depressed cases but 84% of the cumulative time depressed in the sample. Participants with CID (n = 60) exhibited significantly higher preonset levels of 16 of the 18 risk factors than the never-depressed group (n = 315). The TLD group (n = 90) had significantly higher preonset levels of nine risk factors than never-depressed participants. Finally, the CID group had significantly higher levels of nine risk factors than the TLD group, five of which were similar in TLD and never-depressed participants. These findings indicate that differences between CID and TLD are evident before onset and suggest that the liability to CID may be both greater than, and somewhat different from, the liability to TLD. Moreover, they suggest that individuals at risk for a malignant course of depression can be targeted for prevention and early intervention. General Scientific Summary A minority of individuals with a chronic-intermittent course account for a disproportionate share of the burden of depression. However, there are few data on whether they can be distinguished from individuals who will develop more time-limited depressions (TLDs) before the onset of the disorder. We identified a number of preonset variables that distinguished individuals who later developed chronic-intermittent depression (CID) from those who developed TLD. Moreover, individuals who developed TLD did not differ from those who remained depression-free on some of these predictors, suggesting that the liability to CID may be both stronger and somewhat different than the liability to TLD.