Melatonin secretion patterns are associated with cognitive vulnerability and brain structure in bipolar depression.

Circadian rhythm disruption is a core symptom of bipolar disorder (BD), also reflected in altered patterns of melatonin release. Reductions of grey matter (GM) volumes are well documented in BD. We hypothesized that levels and timing of melatonin secretion in bipolar depression could be associated with depressive psychopathology and brain GM integrity. The onset of melatonin secretion under dim light conditions (DLMO) and the amount of time between DLMO and midsleep (i.e. phase angle difference; PAD) were used as circadian rhythm markers. To study the time course of melatonin secretion, an exponential curve fitting the melatonin values was calculated, and the slope coefficients (SLP) were obtained for each participant. Significant differences were found between HC and BD in PAD measures and melatonin profiles. Correlations between PAD and depressive psychopathology were identified. Melatonin secretion patterns were found to be associated with GM volumes in the Striatum and Supramarginal Gyrus in BD. Our findings emphasized the role of melatonin secretion role as a biological marker of circadian synchronization in bipolar depression and provided a novel insight for a link between melatonin release and brain structure.

Cognitive remediation therapy for post-acute persistent cognitive deficits in COVID-19 survivors: A proof-of-concept study.

Cognitive impairments figure prominently in COVID-19 survivors. Cognitive remediation therapy (CRT) improves functional outcomes reducing long-term cognitive deficits in several neurological and psychiatric conditions. Our case-control study investigates the efficacy of a CRT programme administered to COVID-19 survivors in the post-acute phase of the illness. Seventy-three COVID-19 survivors presenting cognitive impairments at one-month follow-up were enrolled. Among them, 15 patients were treated with a two-month CRT programme, and 30 non-treated patients were matched conditional to their baseline cognitive functioning. Cognitive functions were assessed before and after treatment. Depression and quality of life were also evaluated. Mixed model ANOVA revealed a significant effect over time of the CRT programme on global cognitive functioning (F = 4.56, p = 0.039), while no significant effect was observed in the untreated group. We observed a significant effect of the improvement in verbal fluency (χ2 = 7.20, p = 0.007) and executive functions (χ2 = 13.63, p < 0.001) on quality of life. A positive significant correlation was found between depressive symptomatology and verbal fluency (r = -0.35), working memory (r = -0.44), psychomotor coordination (r = -0.42), and executive functions (r = -0.33). Our results could pave the way to a plausible innovative treatment targeting cognitive impairments and ameliorating the quality of life of COVID-19 survivors.

Mood-congruent negative thinking styles and cognitive vulnerability in depressed COVID-19 survivors: A comparison with major depressive disorder.

BACKGROUND: COVID-19 is associated with depressive psychopathology in survivors. Negative thinking styles are a core feature of major depression, fostering the experience of negative emotions and affects and hampering recovery. This cognitive vulnerability has been observed in medical conditions associated with depression, but never explored in post-COVID depression. METHODS: We studied 729 participants: 362 COVID-19 survivors, 73 inpatients with Major Depressive Disorder (MDD), and 294 healthy participants (HC). Severity of depression was self-rated on the Zung Self-Rating Depression Scale (ZSDS). Neuropsychological bias toward negative emotional stimuli and the negative outlook on the self were tested in a self-description task, yielding latencies and frequencies of attribution of morally tuned elements. Dimensions of negative thinking and depressive cognitive style in evaluation of hypothetical events were measured on the Cognition Questionnaire (CQ). RESULTS: 22.4% COVID survivors self-rated depression above the clinical threshold. Frequencies and latencies of attribution of morally negative elements, and CQ scores, correlated between themselves and predicted ZSDS scores, with post-COVID depressed patients showing intermediate scores between the more severe MDD patients, and non-depressed post-COVID participants and HC. LIMITATIONS: Recruitment was in a single center, thus raising the possibility of population stratification. CONCLUSIONS: The breadth of self-reproach and depressive cognitive style in evaluating events showed the same association with severity of depression in MDD and in post-COVID depressed patients, distributing along a gradient of severity, thus suggesting that individual features of negative thinking styles are shared in these conditions, and should be addressed as treatment targets in depressed COVID-19 survivors.