Major Depressive Disorder (MDD) is one of the most common psychiatric disorders, with a large global impact on both the individual and the society. In this narrative review, we summarize neurocognitive deficits during acute and (partially) remitted states of depression. Furthermore, we outline the potential negative effect of cognitive impairment (CI) on functional recovery, and discuss the role of several variables in the development of CI for MDD patients. Though there is cumulating evidence regarding persistent CI in unipolar depression, research on treatment options specific for this patient group is still scarce. Hence the central aim of our review is to present non-pharmacological interventions, which are thought to reduce CI in affected MDD patients. We discuss cognitive remediation therapy (CRT), physical exercise, yoga, mindfulness-based therapy, and modern neuromodulation approaches like neurostimulation and neurofeedback training. In conclusion, we propose future directions for research on CI in depression. Looking further ahead, we suggest creative interventional designs that include a direct comparison of different non-pharmacological treatment approaches on neurocognition and functional outcome of MDD. Furthermore, additive and synergistic effects of CRT with other treatment approaches should be examined and compared to create multimodal and even personalized intervention programs.

No abstract

No abstract

No abstract

Cerebellar involvement in major depressive disorder (MDD) has been demonstrated by a growing number of studies, but it is unknown whether cognitive functioning in depressed individuals is related to cerebellar gray matter volume (GMV) abnormalities. Impaired attention and executive dysfunction are characteristic cognitive deficits in MDD, and critically, they often persist despite remission of mood symptoms. In this study, we investigated cerebellar GMV in patients with remitted MDD (rMDD) that showed persistent cognitive impairment. We applied cerebellum-optimized voxel-based morphometry in 37 patients with rMDD and with cognitive deficits, in 12 patients with rMDD and without cognitive deficits, and in 36 healthy controls (HC). Compared with HC, rMDD patients with cognitive deficits had lower GMV in left area VIIA, crus II, and in vermal area VIIB. In patients with rMDD, regression analyses demonstrated significant associations between GMV reductions in both regions and impaired attention and executive dysfunction. Compared with HC, patients without cognitive deficits showed increased GMV in bilateral area VIIIB. This study supports cerebellar contributions to the cognitive dimension of MDD. The data also point towards cerebellar area VII as a potential target for non-invasive brain stimulation to treat cognitive deficits related to MDD.

BackgroundCognitive impairment is a core feature of major depressive disorder (MDD). Cognitive remediation may improve cognition in MDD, yet so far, the underlying neural mechanisms are unclear. This study investigated changes in intrinsic neural activity in MDD after a cognitive remediation trial.MethodsIn a longitudinal design, 20 patients with MDD and pronounced cognitive deficits and 18 healthy controls (HC) were examined using resting-state functional magnetic resonance imaging. MDD patients received structured cognitive remediation therapy (CRT) over 5 weeks. The whole-brain fractional amplitude of low-frequency fluctuations was computed before the first and after the last training session. Univariate methods were used to address regionally-specific effects, and a multivariate data analysis strategy was employed to investigate functional network strength (FNS).ResultsMDD patients significantly improved in cognitive function after CRT. Baseline comparisons revealed increased right caudate activity and reduced activity in the left frontal cortex, parietal lobule, insula, and precuneus in MDD compared to HC. In patients, reduced FNS was found in a bilateral prefrontal system at baseline (p < 0.05, uncorrected). In MDD, intrinsic neural activity increased in right inferior frontal gyrus after CRT (p < 0.05, small volume corrected). Left inferior parietal lobule, left insula, left precuneus, and right caudate activity showed associations with cognitive improvement (p < 0.05, uncorrected). Prefrontal network strength increased in patients after CRT, but this increase was not associated with improved cognitive performance.ConclusionsOur findings support the role of intrinsic neural activity of the prefrontal cortex as a possible mediator of cognitive improvement following CRT in MDD.

No abstract

Zusammenfassung. Die Studie untersuchte den Unterschied zwischen (teil–)remittierten Patienten mit einer nicht psychotischen depressiven Episode (N = 65) oder Schizophrenie (N = 76) in ihrer Leistung beim Lernen und Gedächtnis von kontextabhängigen (gemessen mittels des Untertests „Logisches Gedächtnis“ aus dem WMS-R) versus kontextunabhängigen (gemessen mittels VLMT) Wortmaterial. Schizophrenie-Patienten zeigten eine signifikant schlechtere Leistung als depressive Patienten im Abruf von kontextabhängigem Wortmaterial sowie beim kontextunabhängigen Wortmaterial in den meisten Gedächtnisparametern, ausgenommen die unmittelbare Merkspanne (Supraspanne). Explorative Analysen der Prozentränge und T-Werte deuteten außerdem darauf hin, dass die Supraspanne auch im Vergleich zur gesunden Bevölkerung in beiden Patientengruppen nicht beeinträchtigt zu sein scheint. Darüber hinaus zeigen Patienten mit einer depressiven Episode beim verzögerten Abruf (VLMT und WMS-R) Defizite. Die praktischen Implikationen werden näher diskutiert.