Related Experiment Video
Updated: Jul 18, 2026

Development of a Virtual Reality Assessment of Everyday Living Skills
Published on: April 23, 2014
Neuropsychological functioning in bipolar disorder and schizophrenia
David J Schretlen1, Nicola G Cascella, Stephen M Meyer
1Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-7218, and Olin Neuropsychiatric Research Center, Hartford Hospital Institute of Living, CT, USA. dschret@jhmi.edu
Background:
Some patients with bipolar disorder (BD) demonstrate neuropsychological deficits even when stable. However, it remains unclear whether these differ qualitatively from those seen in schizophrenia (SZ).
Methods:
We compared the nature and severity of cognitive deficits shown by 106 patients with SZ and 66 patients with BD to 316 healthy adults (NC). All participants completed a cognitive battery with 19 individual measures. After adjusting their test performance for age, sex, race, education, and estimated premorbid IQ, we derived regression-based T-scores for each measure and the six cognitive domains.
Results:
Both patient groups performed significantly worse than NCs on most (BD) or all (SZ) cognitive tests and domains. The resulting effect sizes ranged from .37 to 1.32 (mean=.97) across tests for SZ patients and from .23 to .87 (mean=.59) for BD patients. The Pearson correlation of these effect sizes was .71 (p<.001).
Conclusions:
Patients with bipolar disorder suffer from cognitive deficits that are milder but qualitatively similar to those of patients with schizophrenia. These findings support the notion that schizophrenia and bipolar disorder show greater phenotypic similarity in terms of the nature than severity of their neuropsychological deficits.
Related Concept Videos
Negative and Cognitive Symptoms of Schizophrenia
Negative Symptoms
Negative symptoms of schizophrenia manifest as deficits in normal emotional and behavioral functioning, profoundly impacting daily life. Individuals with schizophrenia often display a flat affect, characterized by a near-total absence of emotional expression,...
Bipolar Disorder
Mania and Antimanic Drugs: Overview
Schizophrenia
Biological Causes of Schizophrenia
Genetic Factors in Schizophrenia
The genetic basis of schizophrenia is strongly supported by family and twin studies.
Psychosis: Pathophysiology of Schizophrenia and Other Psychotic Disorders
Researchers have identified genetic factors that increase susceptibility to schizophrenia, underscoring the intricate interplay between genetics and environment in disease development. At the core of schizophrenia's pathophysiology is excessive dopaminergic neurotransmission within the...