Unravelling basic mechanisms in addiction and neuropsychiatric disorders.

Abstract

Further analyses of NAcc volumes in different psychiatric disorders could contribute to improvement of precise targeting and electrode placement using deep brain stimulation. With publication of the DSM-V, gambling disorder meanwhile also has acquired the status as a behavioral addiction. Grant et al. [3] in an MRI study are the first to compare cortical morphometry in untreated subjects with gambling disorder to healthy controls. The authors found significant reductions in cortical thickness in patients, predominantly in right frontal cortical regions. Taking into account the further pronounced right frontal morphometric abnormalities bespeak a neurobiological overlap with substance disorders. Thus, future studies should not only explore the trait versus state nature of these findings but also eventual similarities with other putative behavioral addictions. In the treatment of bulimia nervosa, the original cognitivebehavioral (CB) maintenance model has widely provided the basis for CBT, but only 40–50 % of treatment completers respond fully and lastingly. Thus, the enhanced CB model (CB-E) extended this approach by encapsulating four additional maintenance factors. Dakanalis et al. [4] evaluated both models allowing for DSM-IV and DSM-5 criteria for bulimic-type eating disorders in a large clinical sample and found the added hypothesized maintenance variables of the CB-E model to improve explanatory utility by better accounting for a greater proportion of variance in dietary restraint and binge eating than the original model. While there exist several studies on self-esteem in anorexia nervosa (AN), so far little was known about AN patient’s estimation of other’s weight and attractiveness. Horndasch et al. [5] discovered a different perception of other women’s bodies belonging to different BMI categories in adolescent AN patients and healthy controls. The observed significant tendency of patient’s engagement in physical comparison with others and weight as Since functional imaging studies have shown a significant association between particularly the nucleus accumbens (NAcc), and the pathophysiology of drug addiction, Seifert et al. [1] investigated potential volume difference of the NAcc in heroin-addicted patients compared to healthy controls and additionally correlated subcortical volumes with clinical measurements of negative effects in addiction. Scanning the groups with 3T structural MRI and performing subcortical segmentation analysis plus assessing anxiety and depressive symptoms showed decreased left NAcc volume in heroin-dependent patients. Furthermore, this group’s depression score was negatively correlated with the left NAcc volume, while the daily opioid dose was positively correlated with the right amygdala volume. Thus, correlating subcortical structures with negative emotions and opioid doses might be interesting in future studies on heroin dependence. These findings are also reported by Muller et al. [2], who in a postmortem study investigated the NAcc and discuss findings with respect to deep brain stimulation, a technique requiring precise computerassisted planning of implementation. The authors calculated NAcc volumes of heroin addicts compared to healthy controls via morphometry of serial whole-brain sections and found larger total brain volume in the heroin group. NAcc volume, again, was nearly equally decreased in the left and the right hemisphere in the heroin-addicted group.