From Inner Sense to Outer Action: Interoception and Impulsive Compulsive Behavior Disorders in Parkinson's Disease

Area of Science:

• Neuroscience
• Psychiatry
• Clinical Psychology

Background:

• Impulsive-compulsive behavior disorders (ICBDs) in Parkinson's disease (PD), including impulse control disorders (ICDs), are associated with dopaminergic treatment and altered reward processing.
• Interoception, the perception of internal bodily signals, is crucial for emotional regulation and decision-making, with potential links to ICDs in PD.
• Existing research suggests altered interoceptive and reward-related brain circuits in PD may contribute to ICDs, but this relationship requires further investigation.

Purpose of the Study:

• To examine the association between the severity of impulse control disorders (ICDs) and various aspects of interoceptive abilities in Parkinson's disease (PD) patients.
• Specifically investigating interoceptive accuracy, insight, and self-reported interoception in relation to ICD severity.
• To explore the potential influence of dopaminergic therapy on the relationship between interoception and ICDs.

Main Methods:

• Fifty-one participants diagnosed with Parkinson's disease (PD) were recruited for the study.
• Assessment included the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease Rating Scale (QUIP-RS) to measure ICD severity.
• Participants also underwent evaluations for interoceptive performance, anxiety, depression, and apathy, alongside Levodopa Equivalent Daily Dose (LEDD) measurement.

Main Results:

• A significant positive correlation was observed between higher ICD severity and increased interoceptive insight and sensibility.
• No statistically significant relationship was found between ICD severity and objective measures of interoceptive accuracy.
• Higher Levodopa Equivalent Daily Dose (LEDD) was associated with reduced interoceptive insight, indicating a potential modulatory effect of dopaminergic medication on meta-cognitive interoception.

Conclusions:

• The study reveals a complex relationship between ICDs and interoception in PD, where heightened self-reported interoception and insight may exacerbate impulsive behaviors.
• This heightened bodily signal awareness could reinforce ICDs by increasing the salience of internal cues.
• Findings implicate reward-related brain circuits, such as the insula and anterior cingulate cortex, in the manifestation of ICDs in Parkinson's disease.