Neural correlates of cue reactivity in individuals with smartphone addiction.

Popularity of smartphones has dramatically increased in the past years, accompanied by increased concerns regarding potentially adverse effects on physical and mental health. Addictive behavior associated with excessive smartphone use, frequently referred to as "smartphone addiction" (SPA), has attracted increased scientific interest. However the neural correlates of SPA are unknown. We used functional magnetic resonance imaging at 3T to investigate the neural correlates of cue reactivity (CR) in individuals with SPA (n = 21) compared to controls (n = 21). SPA was assessed using the Smartphone Addiction Inventory (SPAI), and neural activity was measured by a modified CR task. Contrasts of images of smartphones vs. neutral stimuli and stimuli including active vs. inactive smartphones (p < 0.001, uncorrected for height, followed by correction for spatial extent) were analyzed. In the first contrast, group differences in medial prefrontal (MPFC), occipital, temporal, and anterior cingulate (ACC) cortices, in temporoparietal regions, and cerebellum were found. For active vs. inactive smartphones, group differences were found in frontal operculum/anterior insula and precentral gyrus. Negative correlations were found between MPFC, ACC, precuneus, and precentral gyrus and specific SPAI subscores, i.e. compulsive behavior, functional impairment and withdrawal. This study suggests spatial similarities of CR-related brain activation between addictive smartphone use and other well-known addictive disorders.

Structural and functional correlates of smartphone addiction.

Popularity and availability of smartphones have dramatically increased in the past years. This trend is accompanied by increased concerns regarding potentially adverse effects of excessive smartphone use, particularly with respect to physical and mental health. Recently, the term "smartphone addiction" (SPA) has been introduced to describe smartphone-related addictive behavior and associated physical and psychosocial impairment. Here, we used structural and functional magnetic resonance imaging (MRI) at 3 T to investigate gray matter volume (GMV) and intrinsic neural activity in individuals with SPA (n = 22) compared to a control group (n = 26). SPA was assessed using the Smartphone Addiction Inventory (SPAI), GMV was investigated by means of voxel-based morphometry, and intrinsic neural activity was measured by the amplitude of low frequency fluctuations (ALFF). Compared to controls, individuals with SPA showed lower GMV in left anterior insula, inferior temporal and parahippocampal cortex (p < 0.001, uncorrected for height, followed by correction for spatial extent). Lower intrinsic activity in SPA was found in the right anterior cingulate cortex (ACC). A significant negative association was found between SPAI and both ACC volume and activity. In addition, a significant negative association between SPAI scores and left orbitofrontal GMV was found. This study provides first evidence for distinct structural and functional correlates of behavioral addiction in individuals meeting psychometric criteria for SPA. Given their widespread use and increasing popularity, the present study questions the harmlessness of smartphones, at least in individuals that may be at increased risk for developing smartphone-related addictive behaviors.

Abnormal cerebellar volume in somatic vs. non-somatic delusional disorders.

BACKGROUND: There is abundant evidence for cerebellar involvement in schizophrenia, where the cerebellum has been suggested to contribute to cognitive, affective and motor dysfunction. More recently, specific cerebellar regions have also been associated with psychotic symptoms, particularly with auditory verbal hallucinations. In contrast, little is known about cerebellar contributions to delusions, and even less is known about whether cerebellar involvement differs by delusional content. METHODS: Using structural magnetic resonance imaging at 1.0 T together with cerebellum-optimized segmentation techniques, we investigated gray matter volume (GMV) in 14 patients with somatic-type delusional disorder (S-DD), 18 patients with non-somatic delusional disorder (NS-DD) and 18 patients with schizophrenia (SZ) with persistent non-somatic delusions. A total of 32 healthy controls (HC) were included. Between-group comparisons were adjusted for age, gender, chlorpromazine equivalents and illness duration. RESULTS: Compared to HC, S-DD patients showed decreased GMV in left lobule VIIIa. In addition, S-DD patients showed decreased GMV in lobule V and increased GMV in bilateral lobule VIIa/crus II compared to NS-DD. Patients with SZ showed increased GMV in right lobule VI and VIIa/crus I compared to HC. Significant differences between HC and NS-DD were not found. CONCLUSIONS: The data support the notion of cerebellar dysfunction in psychotic disorders. Distinct cerebellar deficits, predominantly linked to sensorimotor processing, may be detected in delusional disorders presenting with predominantly somatic content.