Plasma IL-6 levels in unmedicated, comorbidity free obsessive-compulsive disorder

Area of Science:

• Neuroscience
• Immunology
• Psychiatry

Background:

• Obsessive-compulsive disorder (OCD) is increasingly investigated for a neuro-immune basis.
• Interleukin-6 (IL-6) is a key cytokine implicated in neurotransmission, but its role in OCD remains unclear.
• Previous studies on plasma IL-6 in OCD have shown inconsistent results, potentially due to medication effects or comorbidities.

Purpose of the Study:

• To investigate plasma IL-6 levels in unmedicated, comorbidity-free adult OCD patients.
• To compare IL-6 levels between OCD patients and healthy controls.
• To explore the correlation between plasma IL-6 levels and clinical variables in OCD.

Main Methods:

• Recruited 49 unmedicated, adult OCD patients and 47 sex-matched healthy controls.
• Measured plasma IL-6 levels using standardized assays.
• Analyzed group differences and correlations with age at onset, illness duration, and severity.

Main Results:

• Plasma IL-6 levels were significantly higher in unmedicated OCD patients (1.31 ± 0.67 ng/ml) compared to healthy controls (1.03 ± 0.47 ng/ml).
• This difference remained significant after controlling for age and sex.
• No significant correlation was found between plasma IL-6 levels and clinical variables such as age at onset, duration of illness, or severity.

Conclusions:

• This study provides evidence for altered immune function in OCD, specifically elevated plasma IL-6 in unmedicated patients.
• These findings suggest that IL-6 may play a role in the neurobiological underpinnings of OCD, potentially affecting neurotransmission and stress response.
• Studying unmedicated, comorbidity-free populations is crucial for reducing heterogeneity and advancing our understanding of OCD's immune alterations.