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Background: Persistent cognitive impairment is frequent across bipolar disorder (BD) and major depressive disorder (MDD), highlighting an urgent need for pro-cognitive treatments. Aim: This study investigated effects of erythropoietin (EPO) on cognitive impairment and dorsal prefrontal cortex (dPFC) activity in affective disorders. Methods: In this randomized, double-blinded, placebo-controlled trial, cognitively impaired patients with remitted BD or MDD received 1 weekly recombinant human EPO (40,000 IU/mL) or saline infusion for a 12-week period. Assessments were conducted at baseline, after 2 weeks of treatment (week 3), immediately after treatment (week 13) and at 6-months follow-up. Participants underwent functional MRI during performance on a n-back working memory (WM) task at baseline and week 3, and for a subgroup 6 weeks post-treatment (week 18). The primary outcome was a cognitive composite score at week 13, whereas secondary outcomes comprised sustained attention and functioning. WM-related dPFC activity was a tertiary outcome. Results: Data were analysed for 101 of the 103 included patients (EPO, n = 58; saline, n = 43). There were no effects of EPO over saline on any cognitive or functional outcomes or on WM-related dPFC activity. Conclusions: The absence of treatment-related changes in cognition and neural activity was unexpected and contrasts with multiple previous preclinical and clinical studies. It is possible that the lack of effects resulted from a recent change in the manufacturing process for EPO. Nevertheless, the findings support the validity of dPFC target engagement as a biomarker model for pro-cognitive effects, according to which treatments that do not improve cognition should not modulate dPFC activity. Trial registrations: EudraCT no.: 2016–004023-24; ClinicalTrials.gov identifier: NCT03315897. [ABSTRACT FROM AUTHOR]

Background: Electroconvulsive therapy (ECT) is an efficient and rapid-acting treatment indicated for severe depressive disorders. While ECT is commonly accompanied by transient memory decline, the brain mechanisms underlying these side effects remain unclear. Aims: In this exploratory functional magnetic resonance (fMRI) study, we aimed to compare effects of ECT versus pharmacological treatment on neural response during episodic memory encoding in patients with affective disorders. Methods: This study included 32 ECT-treated patients (major depressive disorder (MDD), n = 23; bipolar depression, n = 9) and 40 partially remitted patients in pharmacological treatment (MDD, n = 24; bipolar disorder, n = 16). Participants underwent neuropsychological assessment, a strategic picture encoding fMRI scan paradigm, and mood rating. The ECT group was assessed before ECT (pre-ECT) and 3 days after their eighth ECT session (post-ECT). Results: Groups were comparable on age, gender, and educational years (p s ⩾ 0.05). Within-group analyses revealed a selective reduction in verbal learning and episodic memory pre- to post-ECT (p = 0.012) but no decline in global cognitive performance (p = 0.3). Functional magnetic resonance imaging analyses adjusted for mood symptoms revealed greater activity in ECT-treated patients than pharmacologically treated No-ECT patients across left precentral gyrus (PCG), right dorsomedial prefrontal cortex (dmPFC), and left middle frontal gyrus (MFG). In ECT-treated patients, greater decline in verbal learning and memory performance from pre- to post-ECT correlated with higher PCG response (r = −0.46, p = 0.008), but not with dmPFC or MFG activity (p s ⩾ 0.1), post-ECT. Conclusions: Episodic memory decline was related to greater neural activity in the left PCG, but unrelated to increased dmPFC and MFG activity, immediately after ECT. [ABSTRACT FROM AUTHOR]