Abnormalities of striatal morphology in gambling disorder and at-risk gambling

Abstract

Objective. The clinical phenotype of gambling disorder (GD) is suggestive of changes in brain regions involved in reward and impulse suppression, notably the striatum. Studies have yet to characterize striatal morphology (shape) in GD and whether this may be a vulnerability marker.Aims. To characterize the morphology of the striatum in those with disordered gambling (at-risk gambling and GD) versus controls.Method. Individuals aged 18-29 years were classified a priori into those with some degree of GD symptoms (at-risk gambling and GD) or controls. Exclusion criteria were a current mental disorder (apart from GD), history of brain injury, or taking psychoactive medication within 6 weeks of enrollment. History of any substance use disorder was exclusionary. Participants completed an impulsivity questionnaire and structural brain scan. Group differences in volumes and morphology were characterized in subcortical regions of interest, focusing on the striatum.Results. Thirty-two people with GD symptoms (14 at-risk and 18 GD participants) and 22 controls completed the study. GD symptoms were significantly associated with higher impulsivity and morphological alterations in the bilateral pallidum and left putamen. Localized contraction in the right pallidum strongly correlated with trait impulsivity in those with GD symptoms.Conclusions. Morphologic abnormalities of the striatum appear to exist early in the disease trajectory from subsyndromal gambling to GD and thus constitute candidate biological vulnerability markers, which may reflect differences in brain development associated with trait impulsivity. Striatal morphology and associated impulsivity might predispose to a range of problematic repetitive behaviors.

Towards a Better Understanding of the Neurobiological Basis of Problematic Social Media use in Young Adults

“…In addition, providing such novel neurobiological evidence of alterations to the morphology of the striatum with greater levels of problematic social media use, confirms the role of the reward system. The striatum morphology put forth by this study is in line with reward deficit features in behavioural addictions, such as gambling disorder (Grant et al, 2019). While more investigations are needed, our findings provide some support for the addition of problematic social media use to the DSM-5 as a nonsubstance-related disorder (i.e.…”

“…The pallidum has become a target for treatment to regulate relapse for substance use disorders including cocaine, heroin, and alcohol (Kupchik et al, 2021). On the other hand, shape abnormalities of the pallidum have been associated with higher impulsivity scores in individuals with gambling disorders (Grant et al, 2019). We suggest the deformations present in the pallidum are a result of the interplay between impulsivity and reward seeking in problematic social media use.…”

“…found in young adults aged 18-29 with a gambling disorder compared to healthy controls (Grant et al, 2019).…”

“…Both lateral and medial shape differences have been found with cocaine exposure (Wheeler et al, 2013), whereas shape differences associated with tobacco cigarette craving were specific to the dorsal striatum (Janes et al, 2015). When examining behavioural addictions, shape abnormalities were found in the bilateral pallidum and left putaman in individuals with a gambling disorder compared to individuals without a gambling disorder (Grant et al, 2019). Since problematic social media use shares similar reward deficit features with substance-related and non-substance-related disorders, levels of problematic social media use could be associated with similar volumetric and shape differences of the striatum.…”