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Males and females with alcohol dependence have distinct mental health and cognitive problems. Animal models of addiction postulate that the underlying neurobiological mechanisms are partially distinct, but there is little evidence of sex differences in humans with alcohol dependence as most neuroimaging studies have been conducted in males. We examined hippocampal and amygdala subregions in a large sample of 966 people from the ENIGMA Addiction Working Group. This comprised 643 people with alcohol dependence (225 females), and a comparison group of 323 people without alcohol dependence (98 females). Males with alcohol dependence had smaller volumes of the total amygdala and its basolateral nucleus than male controls, that exacerbated with alcohol dose. Alcohol dependence was also associated with smaller volumes of the hippocampus and its CA1 and subiculum subfield volumes in both males and females. In summary, hippocampal and amygdalar subregions may be sensitive to both shared and distinct mechanisms in alcohol-dependent males and females.

Several strands of evidence reported a significant overlapping, in terms of clinical symptoms, epidemiology and treatment response, between the two major psychotic disorders—Schizophrenia (SCZ) and Bipolar Disorder (BD). Nevertheless, the shared neurobiological correlates of these two disorders are far from conclusive. This study aims toward a better understanding of possible common microstructural brain alterations in SCZ and BD. Magnetic Resonance Diffusion data of 33 patients with BD, 19 with SCZ and 35 healthy controls were acquired. Diffusion indexes were calculated, then analyzed using Tract-Based Spatial Statistics (TBSS). We tested correlations with clinical and psychological variables. In both patient groups mean diffusion (MD), volume ratio (VR) and radial diffusivity (RD) showed a significant increase, while fractional anisotropy (FA) and mode (MO) decreased compared to the healthy group. Changes in diffusion were located, for both diseases, in the fronto-temporal and callosal networks. Finally, no significant differences were identified between patient groups, and a significant correlations between length of disease and FA and VR within the corpus callosum, corona radiata and thalamic radiation were observed in bipolar disorder. To our knowledge, this is the first study applying TBSS on all the DTI indexes at the same time in both patient groups showing that they share similar impairments in microstructural connectivity, with particular regards to fronto-temporal and callosal communication, which are likely to worsen over time. Such features may represent neural common underpinnings characterizing major psychoses and confirm the central role of white matter pathology in schizophrenia and bipolar disorder.

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Since its discovery in 1997, the default mode network (DMN) and its components have been extensively studied in both healthy individuals and psychiatric patients. Several studies have investigated possible DMN alterations in specific mental conditions such as bipolar disorder (BD). In this review, we describe current evidence from resting-state functional magnetic resonance imaging studies with the aim to understand possible changes in the functioning of the DMN in BD. Overall, several types of analyses including seed-based and independent component have been conducted on heterogeneous groups of patients highlighting different results. Despite the differences, findings seem to indicate that BD is associated with alterations in both frontal and posterior DMN structures, mainly in the prefrontal, posterior cingulate and inferior parietal cortices. We conclude this review by suggesting possible future research directions.

Highlights We tested gender differences in brain volumes of alcohol dependent vs control groups. Group differences in brain volumes emerged as gross and widespread. Group-by-gender effects emerged in selected brain regions (cerebellum, amygdala) In dependent users, greater alcohol use predicted smaller amygdala and larger cerebellum GM volume. Our results highlight the need to account for gender differences in MRI studies of alcohol dependence.

Impairments in neuro and social cognition are considered core features of schizophrenia (SCZ) since they affect patients' functioning and contribute to poor socio-occupational outcomes. Therefore, the improvement of cognitive performances has become a primary goal in the care of patients with SCZ, especially in the first phases of the disease, as early interventions may favour better long-term outcomes. Cognitive remediation (CR) is a behavioural training aimed at improving cognitive functions with the goal of durability and generalisation in everyday life. Neuroimaging studies suggest that CR leads to neuroplasticity in chronic SCZ, whereas only a few studies tested the neural effects of CR in the early phase of the disease. Thus, in this review, we aimed at summarising CR-induced structural and functional brain changes in early SCZ. Existing evidence showed a protective effect of CR on grey matter volume in selected medial-temporal (i.e. hippocampus, parahippocampus and amygdala) and thalamic regions whereas functional changes affected mostly dorsolateral prefrontal and insular cortices both associated with improvements in cognitive performance and emotion regulation. Overall, CR in early SCZ appears to be associated with neural adaptations mostly allocated in prefrontal and limbic regions, however future longitudinal studies are needed to clarify whether the positive effects of cognitive training persist over time. It may also be interesting to investigate whether the application of CR in the early v. the late stage of the disease may lead to incremental benefits.