In major depressive disorder (MDD), patients may experience a lack of emotional reactivity (ER) and explicit emotional memory (EM) biases during periods of euthymia. ER and explicit EM biases were evaluated in euthymic patients with MDD and healthy controls (HCs) as part of a cross-sectional study published in Psychiatry Research.
The investigators sought to explore ER and explicit EM in patients with MDD, focusing on important cognitive domains including biased reactivity (ie, emotional arousal/reaction), as well as emotional information. In particular, they examined patients’ cognitive phenotypes of these phenomena during euthymia (ie, clinical remission).
All participants attended 2 study visits at the St. Joseph’s Healthcare Hamilton – West 5th Campus Hospital, located in Hamilton, Ontario, Canada. The participants rated the emotional intensity (ie, the emotional reactivity) of 48 negative, 48 positive, and 48 neutral images before returning 1 week later to undergo a surprise recognition memory task. Depressive symptoms were evaluated via the Montgomery-Åsberg Depression Rating Scale (MADRS). Manic symptoms were evaluated with the Young Mania Rating Scale (YMRS), and the Biological Rhythms Interview Assessment for Neuropsychiatry (BRIAN) was used to evaluate circadian rhythm disturbances.
A total of 61 patients were enrolled in the study, 30 of whom had euthymic MDD and 31 of whom were HCs. The mean age of individuals in both groups was similar —
22.2 years in the MDD group versus 22.3 years in the HCC group. Of the 30 participants in the MDD group, 11 were taking a stable dosage of medication and 19 were unmedicated. Participants in both groups demonstrated significantly higher mean intensity ratings for negative versus positive images, for positive versus neutral images, and for negative versus neutral images (P <.0001 for all 3 comparisons).
Additionally, individuals in both arms exhibited significantly reduced memory sensitivity—for example, the ability to accurately distinguish between signal (ie, old stimuli) and noise (ie, new stimuli) for positive versus neutral images (P =.007) and for positive versus negative images (P =.03). Furthermore, individuals in both arms demonstrated significantly reduced normalized memory sensitivity for positive versus negative images (P =.006). No differences were observed between the euthymic MDD group and the HC group with respect to emotional reactivity or EM performance.
The investigators concluded that findings from the current study may inspire further opportunities for future research. Since the current study was cross-sectional in nature, additional studies should focus on exploring ER and explicit EM in patients with MDD using a longitudinal design.
The researchers concluded that “our results also suggest that ER and explicit EM may not be affected in either the active or euthymic phases of MDD and therefore may not fit the cognitive model of depression.”
Disclosures: A study author reported conflicts of interest. See full study for a list of disclosures.
Bogie BJM, Kapczinski FP, McCabe RE, McKinnon MC, Frey BN. Emotional reactivity and explicit emotional memory biases in major depressive disorder during euthymic. Psychiatry Res. 2020;285:112847. doi: 10.1016/j.psychres.2020.112847.