BACKGROUND: Previous studies suggest that mood-incongruent processing constitutes an adaptive mood regulation strategy, and that difficulties in this process may contribute to the maintenance of depression. However, no study has yet examined whether mood-incongruent processing predicts the course and severity of clinical depression.
METHODS: To address this question, the present study used a prospective, longitudinal design to examine the effects of mood-incongruent processing in a sample of 59 clinically depressed patients. At baseline, participants were asked to recall and describe a sad and a happy life event. Participants' utterances were transcribed and analysed using computerized text analysis. Negated emotion words were excluded. The proportion of positive emotion words during sad memory recall was used as an indicator of mood-incongruent processing. After 6 months, participants were re-assessed for symptom levels and the criteria of major depressive disorder (MDD) during the follow-up period.
RESULTS: Higher relative frequency of positive emotion words during sad memory recall was associated with less symptoms of depression at follow-up and shorter time to recovery from MDD, over and above baseline symptoms of depression. The effect was not just due to increased general positivity in emotional expression or emotional expressiveness per se.
LIMITATIONS: The sample size and the timeframe for the follow-up assessment were limited. Furthermore, it is unknown to which degree word use reflects the actual experience of the expressed emotions.
CONCLUSIONS: The findings highlight the role of mood-incongruent processing in the maintenance of depression and advocate a stronger focus on mood-incongruent processing in the treatment of depression.