The intra-day dynamics of affect, self-esteem, tiredness, and suicidality in Major Depression.

Despite growing interest in the temporal dynamics of Major Depressive Disorder (MDD), we know little about the intra-day fluctuations of key symptom constructs. In a study of momentary experience, the Experience Sampling Method captured the within-day dynamics of negative affect, positive affect, self-esteem, passive suicidality, and tiredness across clinical MDD (N = 31) and healthy control groups (N = 33). Ten symptom measures were taken per day over 6 days (N = 2231 observations). Daily dynamics were modeled via intra-day time-trends, variability, and instability in symptoms. MDD participants showed significantly increased variability and instability in negative affect, positive affect, self-esteem, and suicidality. Significantly different time-trends were found in positive affect (increased diurnal variation and an inverted U-shaped pattern in MDD, compared to a positive linear trend in controls) and tiredness (decreased diurnal variation in MDD). In the MDD group only, passive suicidality displayed a negative linear trend and self-esteem displayed a quadratic inverted U trend. MDD and control participants thus showed distinct dynamic profiles in all symptoms measured. As well as the overall severity of symptoms, intra-day dynamics appear to define the experience of MDD symptoms. • The intra-day dynamics of five symptom constructs in Major Depression (MDD) were explored. • The MDD group had distinct dynamics to controls in affect, self-esteem, suicidality and tiredness. • Tiredness had decreased variability and all other symptoms increased variability in MDD. • Increased instability was found in affect, self-esteem and suicidality in MDD. • Positive affect had a more pronounced and tiredness a less pronounced diurnal time-trend in MDD. [ABSTRACT FROM AUTHOR]