The 2-week duration criterion and severity and course of early childhood depression: implications for nosology

Abstract

Background: Although validity for DSM-IV MDD symptom criteria in preschoolers has been demonstrated, whether the 2-week duration criterion is an appropriate threshold of clinical significance at this age remains unclear. The current study aimed to begin addressing this question.

Method: Three hundred and six preschoolers were recruited from community sites and followed longitudinally for 2 years. A subsample including healthy preschoolers (N=77) and those with MDD (N=74) were examined. The MDD group was further divided based upon meeting (DSM, N=24) or failing to meet (<DSM, N=50) the DSM-IV 2-week duration criterion. Groups were compared on parent and teacher report measures of symptom severity and functional impairment at baseline and 2-year follow-up.

Limitations: A larger sample of depressed preschoolers and refined measures of duration are needed to replicate the current study.

Results: Preschoolers with MDD differed significantly from controls on the majority of measures examined regardless of duration status and time of assessment. Further, the DSM group significantly differed from the<DSM group at baseline on measures of MDD symptom severity and impairment. No differences in the risk of a MDD diagnosis at follow-up were found on the basis of duration group status.

Conclusions: DSM-IV duration criterion failed to capture all clinically affected preschoolers at baseline or confer greater predictive validity for a depression diagnosis 2 years later. Findings suggest that preschoolers meeting all DSM-IV MDD criteria except for episode duration exhibit a clinically significant form of depression and experience a 2-year MDD outcome similar to those meeting full criterion.