Objective: Despite growing evidence in the field of cognitive function in mood disorders, the neurocognitive profiles of patients with unipolar and bipolar depression still need further characterization. In this study, we applied network analysis, hypothesizing this approach could highlight differences between Major Depressive Disorder (MDD) and Bipolar Disorder (BD) from a cognitive perspective. Methods: The cognitive performance of 109 patients (72 unipolar and 37 bipolar depressed outpatients) was assessed through the Montreal Cognitive Assessment (MoCA) and a series of clinical variables was collected. Differences in cognitive performance between MDD and BD patients were tested using non parametric tests. Moreover, a network graph representing MoCA domains as nodes and Spearman's rho correlation coefficients between the domains as edges was constructed for each group. Results: The presence of mild cognitive impairment was observed both in MDD and BD patients during depression. No statistical significant difference was found between the two groups in terms of overall cognitive performance and across single domains. Nonetheless, network analytic metrics demonstrated different roles of memory and executive dysfunction in MDD vs BD patients: in particular, MDD network was more densely interconnected than BD network and memory was the node with the highest betweenness and closeness centrality in MDD, while executive function was more central in BD. Conclusions:From a network analytic perspective, memory impairment displays a central role in the cognitive impairment of patients with unipolar depression, whereas executive dysfunction appears to be more central in bipolar depression. Further research is warranted to confirm our results.

Introduction: In this study we estimated the rate and the trajectory of cognitive impairment in a naturalistic sample of outpatients with major depressive disorder (MDD) and bipolar disorder (BD) and its correlation with different variables. Materials and methods: An overall sample of 109 outpatients with MDD or BD was assessed for multiple clinical variables, including duration of untreated illness (DUI), and tested using the Montreal Cognitive Assessment (MoCA) during Major Depressive Episodes (MDE) and after remission. Correlations between MoCA scores and the clinical variables were then computed. Results: About 50% of patients with MDD and BD showed mild cognitive impairment during MDE. Improvement of cognitive function between depression and remission was significant, even though residual symptoms were observed especially in the most impaired patients. Of note, cognitive performance during depression was negatively associated with depression severity and DUI. Discussion: Present findings confirm available evidence about patterns of cognitive impairment in mood disorders, in terms of prevalence and persistence beyond remission in most severe cases. Moreover, a longer DUI was associated with worse cognitive performance during depression, and consequently with poorer outcome, underlining the importance of prompt treatment of these disorders also in light of a cognitive perspective.

Aim: Up to just over half of bipolar disorder (BD) patients report at least one-lifetime anxiety disorder (AD). In some, anxiety represents the earliest psychiatric manifestation, prior to any mood episode. We sought to investigate prevalence of AD subtypes as first psychiatric manifestations and AD's relations with duration of untreated illness (DUI) and treatment among BD outpatients. Methods: We recruited patients referred to the Centre for the Treatment of Depressive Disorders in Milan, diagnosed with BD-I, BD-II, BD not otherwise specified (BD-NOS) and cyclothymia according to Diagnostic and Statistical Manual fourth edition-text revision criteria. Several clinical characteristics were assessed through retrospective chart review and/or direct patient interviews. Based on presence/ absence of an AD at psychiatric onset, eligible subjects were stratified into two groups (A+ and A−) and clinical features were compared between these groups and between BD subtypes. Results: We analysed 260 BD patients (77 BD-I, 122 BD-II, 45 BD-NOS and 16 cyclothymia). An AD was the first psychiatric manifestation in 69 patients (26.5%). BD-II and BD-NOS more frequently had an AD at psychiatric onset, with panic disorder being the most common AD. Among A+ vs A−, age at BD onset was younger, duration of untreated BD illness (DUI) was longer, and a mood stabilizer/antipsychotic was less often prescribed at psychiatric onset.