Pain perception and physiological correlates in body-focused repetitive behavior disorders

Area of Science:

• Psychiatry
• Neuroscience
• Behavioral Science

Background:

• Body-focused repetitive behaviors like trichotillomania (TTM) and skin-picking disorder (SPD) are linked to pleasure or relief, suggesting altered pain perception.
• However, conclusive evidence on pain perception in TTM and SPD is lacking.

Purpose of the Study:

• To investigate pain perception and its physiological correlates in adults with TTM, SPD, and healthy controls.
• To examine associations between pain perception, illness severity, and comorbid depression.

Main Methods:

• A multisite international study involving adults with TTM (n=31), SPD (n=24), and healthy controls (HCs; n=26).
• Utilized the cold pressor test to measure pain perception and cardiovascular parameters.
• Analyzed pain ratings, latency to pain tolerance, diastolic blood pressure, illness severity, and depression across groups.

Main Results:

• No significant differences were found in pain ratings over time or latency to pain tolerance between the groups.
• Illness severity was not associated with pain ratings in TTM or SPD.
• Individuals with TTM exhibited higher diastolic blood pressure compared to those with SPD and HCs, but pain perception did not differ based on depression status.

Conclusions:

• General pain perception abnormalities do not appear to be involved in the etiology of TTM and SPD.
• Further research should explore other underlying mechanisms, such as abnormal reward processing, to explain hair-pulling and skin-picking behaviors.