background The variability in treatment response in depression remains largely unexplained. Although the treatment of depression is about restoration of the imbalance between an excess of negative affect (na) and a shortage of positive affect (pa), there is no knowledge of how na and pa dynamically influence each other in depression, or how this may impact treatment response.
aim To examine pa-na dynamics and their effects on treatment response in depression.
methods Participants were depressed help-seeking individuals starting out-patient treatment for a dsm-iv diagnosis of depression. The experience sampling method (esm) was used at baseline to examine the dynamic relationship between experience of na and pa, as well as its association with future response to treatment. The Hamilton Depression Rating Scale (hdrs) was administered at baseline and at each of six monthly follow-up measurements.
results Future response to treatment was significantly associated with altered baseline na-pa dynamics in individuals with previous depressive episodes. In this group, daily life increases in pa were followed by suppression of na over the following hours. Response to treatment was likewise associated with baseline na-pa dynamics. Patients who show no suppression in na after pa increase, have a lower reduction in follow-up depressive symptoms compared to patients who do show na suppression after pa increase.
conclusion Subtle individual differences in daily life emotional dynamics predict future treatment outcome in depression. The ability to use sources of natural reward in daily life in order to suppress negative emotions occurring later in the day may represent the mechanism by which depressed patients are able to compensate their lack of pa and facilitate the process of recovery.