Nature and specificity of altered cognitive functioning in IBS

Area of Science:

• Neuroscience
• Gastroenterology
• Psychiatry

Background:

• Cognitive dysfunction is observed in Irritable Bowel Syndrome (IBS) patients.
• The specific causes, including subtypes, pathophysiology, traits, or psychiatric comorbidities, remain unclear.

Purpose of the Study:

• To investigate cognitive function in Irritable Bowel Syndrome (IBS) patients.
• To compare cognitive performance between IBS subtypes (IBS-D and IBS-C) and healthy controls.
• To explore the relationship between cognitive function, symptom severity, and psychiatric comorbidities.

Main Methods:

• Forty Rome-III IBS patients (20 IBS-D, 20 IBS-C) and 40 healthy controls were assessed.
• Cognitive function was evaluated using the Continuous Performance Test (CPT) and Wisconsin Card Sorting Test (WCST).
• Anxiety, depression, somatization, and bowel symptoms were measured; psychiatric diagnoses were confirmed using SCID-I.

Main Results:

• IBS patients exhibited impaired attentional and executive functions, evidenced by increased reaction time variability on CPT and difficulties with set maintenance/perseverative errors on WCST.
• Standard deviation of reaction time (SDRT) on CPT significantly differentiated IBS patients from controls, even after controlling for anxiety and depression.
• No significant cognitive differences were found between IBS subtypes (IBS-C vs. IBS-D) or between pure IBS and IBS with generalized anxiety disorder (GAD).

Conclusions:

• Irritable Bowel Syndrome (IBS) is associated with attentional and executive dysfunction, independent of IBS subtype.
• Cognitive impairment in IBS is heterogeneous and shows complex correlations with state-trait characteristics and anxiety comorbidities.
• Sustained attention deficits, specifically increased SDRT, appear to be a key cognitive marker differentiating IBS patients from healthy individuals.