A Neural Signature of Touch Aversion and Interpersonal Problems in Borderline Personality Disorder

Area of Science:

• Neuroscience
• Psychiatry
• Social Psychology

Background:

• Borderline personality disorder (BPD) is characterized by significant social impairments and interpersonal difficulties.
• Social touch plays a crucial role in social bonding, but BPD patients may have a negative perception of it.
• The neural underpinnings of altered touch processing in BPD and its connection to social deficits remain largely unknown.

Purpose of the Study:

• To investigate the neural mechanisms of social touch processing in BPD patients.
• To examine how touch perception and attitude towards social touch are affected in BPD.
• To assess the impact of dialectical behavior therapy (DBT) on social touch processing in BPD.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain responses to affective (CT-optimal) and discriminative (CT-suboptimal) touch.
• 55 BPD patients and 31 healthy controls were studied before and after a 4-week residential DBT program.
• Attitudes towards social touch, touch allowance maps, BPD symptoms, and interpersonal problems were assessed.

Main Results:

• Before DBT, BPD patients displayed a negative bias towards social touch, with more negative attitudes and smaller comfort zones than controls.
• Reduced activation in the posterior insular cortex during affective touch correlated with interpersonal problem severity in BPD patients.
• Despite symptom improvement post-DBT, altered social touch processing remained, suggesting trait-like disturbances.

Conclusions:

• Impaired insula-mediated integration of affective and sensory touch components may be a biological marker for BPD's interpersonal problems.
• Dysfunctional social touch processing is a persistent feature in BPD, even after therapeutic intervention.
• These findings highlight the link between aberrant touch processing and social deficits in BPD.