Structural neuroimaging of skin-picking disorder

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Skin-picking disorder (SPD) is classified as an obsessive-compulsive and related disorder (OCRD).
• SPD is characterized by repetitive skin manipulation, leading to physical and psychological harm.
• The underlying neuroanatomy of SPD remains largely unexplored.

Purpose of the Study:

• To investigate the neuroanatomical differences in patients with SPD compared to healthy controls.
• To explore how age of symptom onset influences brain structure in SPD.
• To identify potential brain regions associated with SPD pathophysiology.

Main Methods:

• A voxel-based morphometry (VBM) study was conducted on 220 participants (123 with SPD, 97 controls).
• Grey matter volume (GMV) was compared between SPD patients and controls.
• SPD patients were subgrouped by age of symptom onset (before puberty, during puberty, adulthood) for further analysis.

Main Results:

• Patients with SPD exhibited significantly reduced GMV in the insula, orbitofrontal cortex, pallidum, cerebellum, supramarginal gyrus, frontal pole, and occipital regions compared to controls.
• Early onset SPD (before puberty) was associated with more focused skin-picking behavior.
• Early onset was also linked to reduced GMV in the insula, orbitofrontal cortex, paracingulate, and superior temporal regions.

Conclusions:

• SPD is associated with grey matter volume reductions in brain areas crucial for interoception, emotional regulation, and motor control.
• Findings suggest a partial overlap in neuroanatomical characteristics between SPD and obsessive-compulsive disorder (OCD).
• The distinct clinical and morphometric profiles across age-of-onset groups highlight the heterogeneity of SPD, necessitating further research.