Predictors of change in life skills in schizophrenia after cognitive remediation.

Few studies have investigated predictors of response to cognitive remediation interventions in patients with schizophrenia. Predictor studies to date have selected treatment outcome measures that were either part of the remediation intervention itself or closely linked to the intervention with few studies investigating factors that predict generalization to measures of everyday life-skills as an index of treatment-related improvement. In the current study we investigated the relationship between four measures of neurocognitive function, crystallized verbal ability, auditory sustained attention and working memory, verbal learning and memory, and problem-solving, two measures of symptoms, total positive and negative symptoms, and the process variables of treatment intensity and duration, to change on a performance-based measure of everyday life-skills after a year of computer-assisted cognitive remediation offered as part of intensive outpatient rehabilitation treatment. Thirty-six patients with schizophrenia or schizoaffective disorder were studied. Results of a linear regression model revealed that auditory attention and working memory predicted a significant amount of the variance in change in performance-based measures of everyday life skills after cognitive remediation, even when variance for all other neurocognitive variables in the model was controlled. Stepwise regression revealed that auditory attention and working memory predicted change in everyday life-skills across the trial even when baseline life-skill scores, symptoms and treatment process variables were controlled. These findings emphasize the importance of sustained auditory attention and working memory for benefiting from extended programs of cognitive remediation.

Symptoms versus neurocognition as predictors of change in life skills in schizophrenia after outpatient rehabilitation.

A growing body of literature has shown that neurocognitive deficits in schizophrenia account for 20-60% of the variance in measures of outcome, and in many studies are more closely related to outcome than symptoms [Green, M.F., Kern, R.S., Braff, D.L., Mintz, J., 2000. Neurocognitive deficits and functional outcome in schizophrenia: are we measuring the "right stuff"? Schizophr. Bull. 26(1), 119-136; Green, M.F., Kern, R.S., Heaton, R.K., 2004. Longitudinal studies of cognition and functional outcome in schizophrenia: implications for MATRICS. Schizophr. Res. 72(1), 41-51]. Most of these studies have been cross-sectional, few longitudinal studies have investigated the degree to which neurocognition and symptoms predict ability to benefit from outpatient rehabilitation, and no longitudinal studies use measures of everyday life skills that are performance-based. In the current study we investigated the relationship between five measures of neurocognitive function, crystallized verbal ability, visual sustained vigilance, verbal learning, problem-solving, and processing speed, and two measures of symptoms, total positive and negative symptoms, and change on a performance-based measure of everyday life skills after a year of outpatient rehabilitation. Rehabilitation consisted of both psychosocial and cognitive interventions. Forty-six patients with schizophrenia or schizoaffective disorder were studied. Results of a linear regression model revealed that verbal learning predicted a significant amount of the variance in change in performance-based measures of everyday life skills after outpatient rehabilitation, even when variance for all other variables in the model was accounted for. Measures of crystallized verbal ability, sustained visual vigilance, problem-solving, processing speed and symptoms were not linked to functional status change. These findings emphasize the importance of verbal learning for benefiting from psychosocial and cognitive rehabilitation interventions, and suggest the development of alternative rehabilitation strategies for those who do not benefit.

Computer-assisted cognitive remediation in schizophrenia: what is the active ingredient?

An emerging body of research has shown that computer-assisted cognitive remediation, consisting of training in attention, memory, language and/or problem-solving, produces improvement in neurocognitive function that generalizes to untrained neurocognitive tests and may also impact symptoms and work functioning in patients with schizophrenia. The active ingredient of these interventions, however, remains unknown as control groups in these studies have typically included few, if any, of the elements of these complex behavioral treatments. This study compared the effects of an extended (12-month), standardized, computer-assisted cognitive remediation intervention with those of a computer-skills training control condition that consisted of many of the elements of the experimental intervention, including hours spent on a computer, interaction with a clinician and non-specific cognitive stimulation. Forty-two patients with schizophrenia were randomly assigned to one of two conditions and were assessed with a comprehensive neuropsychological test battery before and after treatment. Results revealed that cognitive-remediation training produced a significant improvement in working memory, relative to the computers-skills training control condition, but that there was overall improvement in both groups on measures of working memory, reasoning/executive-function, verbal and spatial episodic memory, and processing speed. Taken together, these findings suggest that specific practice in neurocognitive exercises targeted at attention, memory and language, produce improvements in neurocognitive function that are not solely attributable to non-specific stimulation associated with working with a computer, interacting with a clinician or cognitive challenge, but that non-specific stimulation has a salutary effect on neurocognition as well.

Neurocognitive function in schizophrenia at a 10-year follow-up: a preliminary investigation.

INTRODUCTION: A wealth of evidence indicates that neurocognitive deficits are evident in patients with schizophrenia at both illness onset and after many years of treatment. Little is known regarding if or how these deficits change during the lifespan. The goal of the study was to evaluate changes in full-scale intelligence quotient and neurocognitive test performance over a 10-year interval in patients with schizophrenia. METHODS: Twelve patients were administered the Wechsler Adult Intelligence Scale-Revised as a measure of intellectual function and a neuropsychological test battery including measures of attention, verbal and non-verbal memory, language, visuospatial function, problem-solving, and motor function at entry to the study and at a 10-year follow-up. RESULTS: With the exception of performance on a measure of speeded motor sequencing, there was no significant decline in any of the measures at 10-year follow-up. Results from a measure of sustained auditory attention showed improvement at follow-up. DISCUSSION: These data support a neurodevelopmental model of schizophrenia for young adult to middle-age patients by suggesting that neurocognitive deficits that emerge either before disease onset or early in the course of the illness remain stable as the patient ages. CONCLUSION: Overall, measures of intelligence quotient, as well as specific neurocognitive skills, do not decline over a 10-year period in at least a subgroup of patients with schizophrenia.