Aerobic capacity is associated with global functioning in people with schizophrenia

Although antipsychotic medications help manage clinical symptom severity, most people with schizophrenia continue to function poorly in the community.

To determine whether the Global Assessment of Functioning (GAF) score is associated with aerobic capacity in people with schizophrenia.

Thirty-four male (34.1 ± 12.0 years) and 16 female (33.1 ± 8.7 years) persons with schizophrenia performed the Astrand-Rhyming cycle ergometer test in order to estimate the maximal oxygen uptake (VO2max) and were assessed with the GAF, the Psychosis Evaluation tool for Common use by Caregivers and the International Physical Activity Questionnaire.

The mean GAF-score was 41.9 ± 9.4, while the mean estimated VO2max was 34.5 ± 8.7mlO2/min/kg. There was a moderate association between the GAF-score and VO2max (r = 0.45, p < 0.001). Positive, negative and cognitive symptoms were negatively (p < 0.05) associated with the GAF-score, physical activity participation positively (p < 0.05). A backward regression analysis demonstrated that VO2max explained 19.1% of the GAF-score variance.

In people with schizophrenia, the aerobic capacity is associated with a person's global functioning. Clinicians should consider incorporating assessment of aerobic capacity into their test battery in order to measure the health consequences of schizophrenia and its treatment.