Cognitive toxicity of pharmacotherapeutic agents used in social anxiety disorder

Objective: To compare cognitive impairment of medications used in social anxiety disorder (SAD). Methods: Data from peer-reviewed publications (1975-2007) of controlled, crossover design, pharmacodynamic studies on SAD medications in healthy volunteers were analysed. The number of objective psychometrics for each drug/dose level at all time points after dosing, and of instances of statistically significant impairment of cognitive function, enabled calculation of drug-induced cognitive impairment. The magnitude of impairment between drugs was compared using proportional impairment ratios (PIRs). Results: Olanzapine, oxazepam, lorazepam and mianserin had twice the average cognitive toxicity of other treatments. Selective serotonin reuptake inhibitors (SSRIs) impaired cognition to a lesser extent than other pharmacological groupings. There was extensive intra-class variation: fluvoxamine (PIR = 0.08) possessed little detrimental cognitive activity, whereas sertraline (PIR = 5.33) caused impairment over five times the SSRI group average. Benzodiazepines caused noticeable cognitive impairment. Conclusions: Substantial differences exist, both between and within therapeutic classes, in the behavioural toxicity of medications used for SAD.