HONOLULU— Neurocognitive measures are valid predictors of the long-term quality of life for outpatients with severe and persistent mental illness, a finding that provides new incentive for targeting cognitive interventions in this population, according to Daryl E. Fujii, PhD, and colleagues. Results from their 15-year study found that neuropsychologic variables such as short-term and working memory, executive functioning, and motor skills were associated with various outcome measures regarding a patient’s overall quality of life.

“Our findings supported the general hypothesis that neurocognition is predictive of quality of life in the severe and persistent mental illness population,” said Dr. Fujii. “This makes intuitive sense, given that neurocognition has consistently been associated with overlapping outcome measures such as vocational success and independent living, as well as social problem-solving skills and an ability to learn from rehabilitation modules that may impact quality of life.” Dr. Fujii, a Professor in the Department of Psychology, Hawaii State Hospital, in Kaneohe, Hawaii, presented his team’s findings at the 14th Annual Meeting of the American Neuropsychiatric Association.

Prior studies have found that quality of life in patients with severe and persistent mental illness can be predicted by psychiatric symptoms, quality of clinical treatment, and medication side effects, as well as by psychosocial environmental factors such as positive family interactions. Neurocognition, however, has not been highly investigated and reported as it pertains to quality of life in these patients, according to Dr. Fujii. “This lack of neurocognitive studies is surprising, as neurocognition has been found to have important predictive validity for functional outcome in persons with severe and persistent mental illness,” he noted.

A NEUROCOGNITIVE FORECAST

Dr. Fujii’s team used specific areas of neurocognition as predictor variables and outcome measures to evaluate different dimensions in quality of life. Unlike previous trials on quality of life, Dr. Fujii’s study is longitudinal, with outcomes measured more than five years after the collection of predictor variables. All subjects were merged from both a statewide study of managed care versus fee-for-service treatment of adults with severe and persistent mental illness as well as a state hospital neuropsychology database. Diagnosis was based on DSM-IV criteria and made by the most recent treating psychiatrist.

Thirty subjects (23 males) met the criteria for inclusion. The mean age at the time of neuropsychologic testing was 28, and the average age at Brief Quality of Life Inventory (a self-report questionnaire) administration was 43, which yielded a mean duration between testing and assessment of 15 years. Four patients were diagnosed with schizophrenia, nine with paranoid schizophrenia, eight with schizoaffective disorder, six with bipolar disorder, two with undifferentiated schizophrenia, and one with psychotic disorder.

The neuropsychologic measures were selected based on cognitive areas that are deficient in those with severe and persistent mental illness. Data were analyzed using stepwise multiple regressions with neurocognitive measures entered as predictor variables; scores of the Brief Quality of Life Inventory subjective and objective subscales served as the dependent variables.

The investigators found that memory accurately predicted a patient’s future income, satisfaction with daily activities, and general health. Executive functioning was highly predictive of a patient’s contact with his or her family and financial support. A patient’s motor skills had a high rate of accuracy in predicting satisfaction with family contacts. Furthermore, the researchers found that working memory was predictive of a patient’s victimization and satisfaction with social contacts.

“Our findings provide additional support for the long-term predictive ability of neurocognition on functional outcome in persons with severe and persistent mental illness,” Dr. Fujii stated.

—Colby Stong

Suggested Reading
Fujii DE, Wylie AM. Neurocognition and community outcome in schizophrenia: long-term predictive validity. Schizophr Res. 2003;59:219-223.