Symptom profiles of DSM-IV-defined remission, recovery, relapse, and recurrence of depression: the role of the core symptoms

Background Depression outcomes in research and clinical practice are commonly defined by the concepts of remission, recovery, relapse, and recurrence. Despite their widespread use, there has been little empirical examination of these concepts. Therefore, we investigated profiles of individual symptoms during each of these phases of depression. Methods In a 3-year prospective study of 267 depressed primary care patients, we established the presence or absence of the individual DSM-IV depressive symptoms week-by-week during DSM-IV-defined remissions, recoveries, relapses, and recurrences. We measured symptoms in 12 quarterly assessments using the Composite International Diagnostic Interview. Results Remissions were characterized by double the proportion of time that the core symptoms were present compared to the initial phase of recoveries after a major depressive episode (MDE; 59 versus 32%; Z = -3.03; P = .002). Before a relapse, remissions again showed elevated levels of core symptoms in comparison to the final phase of recoveries before a recurrence (58 versus 26%; Z = -2.99; P = .003). Conclusions Compared with the initial and final phases of recoveries, remissions showed a consistently higher level of core symptoms. Clinically, this means that unresolved core symptoms in the direct aftermath of a MDE seem to constitute a risk for relapse and should be the target of preventive or augmented interventions