A statistical approach for classifying change in cognitive function in individuals following pharmacologic challenge: an example with alprazolam

Introduction: The effects of any drug treatment on cognitive function are typically studied in groups of subjects. Observations made about the behavior of the drug, in the study sample, are then generalized to the population from which the sample was drawn. However, the magnitude and pharmacodynamic qualities of the response to many central nervous system-active drugs are known to vary in the population. Therefore, it is useful to consider statistical models for the detection of cognitive change in response to a drug treatment in individual subjects. Materials and methods: In this report, we first outline the statistical assumptions and requirements for the reliable estimation of clinically relevant individual change in cognition. We then used the sedative benzodiazepine, alprazolam, as a pharmacologic challenge in healthy volunteer subjects to test our statistical model, using a parallel groups placebo-controlled study design. After treatment, the nature and severity of alprazolam-induced cognitive change was determined for each individual. Results: Our proposed method and analysis showed an excellent sensitivity and specificity for alprazolam-related cognitive deterioration in individuals. conclusions: These findings, although preliminary, suggest that statistically reliable decisions about the effects of sedative drugs on cognition can be made for individuals.