Cognitive Inflexibility Shares Across Schizophrenia and Obsessive-Compulsive Disorder: A Task-Based Functional MRI...

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Schizo-obsessive comorbidity (SOC) involves obsessive-compulsive symptoms (OCS) in schizophrenia (SCZ), correlating with severe psychopathology and poor prognosis.
• Shared cognitive impairments in inhibition and cognitive flexibility between schizophrenia and obsessive-compulsive disorder (OCD) may underlie SOC.
• Neural mechanisms of SOC remain largely unknown.

Purpose of the Study:

• To directly compare neural activations related to inhibition and cognitive flexibility.
• To investigate differences between patients with SOC, SCZ, OCD, and healthy controls (HCs).

Main Methods:

• fMRI scans were conducted on 28 SOC patients, 33 SCZ patients, 30 OCD patients, and 33 HCs.
• Participants performed a combined shifting go/no-go task.
• Analysis focused on shifting-related and stopping-related neural activations.

Main Results:

• All clinical groups exhibited reduced shifting-related activation in specific brain regions compared to HCs; SOC patients showed significantly lower activation than SCZ and OCD patients.
• OCD and SOC patients displayed greater stopping-related hyperactivation in the left precuneus compared to SCZ patients.
• Behaviorally, SOC and SCZ patients made more errors in commission and shifting tasks than OCD and/or HCs.

Conclusions:

• Cognitive inflexibility is a shared characteristic across schizophrenia, OCD, and SOC.
• The co-occurrence of schizophrenia and OCS appears to amplify neural alterations, suggesting additive effects.