An increase in joy after two weeks is more specific of later antidepressant response than a decrease in sadness

Early improvement in positive emotions-more than decreases in negative emotions-was highly predictive of treatment response in an ecologically valid prospective manner. This result needs replication with simpler assessments to determine whether it can be translated into clinical practice.

2049 adult depressed outpatients receiving agomelatine were assessed at inclusion, week 2, and week 6 using the clinician-rated Quick Inventory of Depressive Symptomatology, Sheehan Disability Scale, Clinical Global Impression scale, and Multidimensional Assessment of Thymic States (MATHYS), an auto-questionnaire rating the frequency of emotions, including sadness and joy, over the previous week.

Joy and sadness had a relatively low correlation coefficient at baseline (r=-0.277), joy (r=-0.160) being less correlated with clinical severity than sadness (r=0.317). An increase in joy at week 2 had higher specificity (85.04%) and positive predictive value (70.55%) for treatment response than decreased sadness (57.92% and 66.04%, respectively), and the global capacity of the former to predict remission, either clinical (Yule Q coefficient, 39.96%) or functional (44.35%), was even better compared to the prediction of clinical response (37.38%).

MATHYS retrospectively assesses emotions, with five possible ratings only, relying on self-rated frequencies. With only a 6-week follow-up, conclusions are limited to short-term aspects of clinical and functional remission.

Early improvement in joy during the first 2 weeks of treatment is strongly specific for treatment response and remission. The frequency of joy captures the predictivity and may deserve further study regarding inclusion in depressive rating scales.