Drug Effects: Do Test Results Correlate With Clinical Gains?

Drug Effects: Do Test Results Correlate With Clinical Gains?

There are any number of ways to measure the effects of psychoactive medications, ranging from objective assessments of behavioral change to neuropsychological testing to subjective global ratings by physicians or patients. Several recent studies have examined the question of whether medication-induced improvements in neuropsychological test performance correlated with gains in healthful functioning.

Social competence and social cognition were suggested as viable outcome measures for clinical trials by one research group.1 Improved executive functioning, one neuropsychological measure of capacity for social and occupational functioning, was correlated with therapeutic drug effect in another study.2 A third group of researchers sought a link between medication treatment efficacy and such complex states as consideration of others, personal responsibility, and self-esteem.3

In an 8-week clinical trial comparing the efficacy and tolerability of quetiapine (Seroquel) and risperidone (Risperdal), Harvey and colleagues1 ascertained changes in social competence, rated with the Social Skills Performance Assessment, a validated measure of interactive social skills, along with changes in social cognition, assessed with the Penn Emotional Acuity Test, which indexes the ability to perceive intensity of affective expression.

The researchers indicated that this was the first study of antipsychotic effects that used performance-based measures of social competency. They credited the impetus for the study to an FDA-NIMH workshop on trial design that recommended the use of performance-based measures of functional capacity in clinical trials involving patients with schizophrenia.4

“While neuropsychological test performance is correlated with social outcomes in patients with schizophrenia,” Harvey and colleagues explained, “there is little evidence to date that changes in neuropsychological performance are associated with changes in these outcomes.”

The researchers found little difference between the 2 antipsychotic treatments on the improvement of symptoms, measured with the PANSS (Positive and Negative Syndrome Scale), but a reduction in PANSS total score with quetiapine treatment predicted improvement in delayed recall, and an improved PANSS measure of positive symptoms predicted improvements in total learning. Risperidone-associated changes in positive symptoms were related to improvements in Rey Auditory Verbal Learning Test performance and in total learning.

“Social competence measures are positively affected by treatment with atypical antipsychotics,” the research-ers concluded. “These treatment-related changes in social skills performance are correlated with concurrent improvement in neuropsychological performance.”


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