Elevated antisaccade error rate as an intermediate phenotype for psychosis across diagnostic categories

Area of Science:

• Neuroscience
• Psychiatry
• Genetics

Background:

• Elevated antisaccade error rate, a measure of inhibitory control, is a potential intermediate phenotype for schizophrenia.
• This study investigates if antisaccade errors mark liability across psychotic disorders and if they are a risk indicator independent of general cognitive deficits.

Purpose of the Study:

• To determine if elevated antisaccade error rate is a shared intermediate phenotype across schizophrenia, schizoaffective disorder, and psychotic bipolar disorder.
• To assess if antisaccade error rate predicts psychosis risk beyond generalized cognitive impairment.
• To explore neurophysiological mechanisms underlying antisaccade errors in different psychotic disorders.

Main Methods:

• Recruited probands with schizophrenia, schizoaffective disorder, psychotic bipolar disorder, their first-degree relatives, and healthy controls.
• Administered antisaccade and prosaccade tasks to assess inhibitory control and attentional shifting.
• Utilized a neuropsychological battery to measure generalized cognitive function.

Main Results:

• Antisaccade error rates were elevated in all proband groups, most severely in schizophrenia, and were familial.
• Increased error rates were found in relatives, irrespective of psychosis history or traits.
• Elevated antisaccade error rate persisted after controlling for generalized cognitive impairment, indicating it is a distinct risk indicator.

Conclusions:

• Elevated antisaccade error rate is a valid intermediate phenotype for psychosis liability across diagnostic categories.
• This deficit tracks psychosis risk independently of generalized cognitive deficits.
• Schizophrenia exhibits more severe antisaccade impairment, suggesting specific prefrontal inhibitory control deficits.