The effects of long-term benzodiazepine treatment and graded withdrawal on psychometric performance.

Twelve patients were assessed prior to and during 4 weeks' graded withdrawal from long-term benzodiazepine treatment. A control group of ten healthy drug-free individuals were assessed over the same period. Psychometric measures included Four Choice Reaction Time--Decision (FCRT-D), Four Choice Reaction Time--Movement (FCRT-M), Sensory Threshold Detection (STD) and Key Tapping Rate (KTR). Patients anxiety level was monitored using the Hamilton Rating Scale (HAM) and a Visual Analogue Self-Report Measure (VASR). There was no evidence of psychometric practice effects and no significant changes in patients anxiety ratings. Prior to withdrawal the patient group showed significantly impaired performance compared to the control group on FCRT-D and STD, tasks primarily involving visual sensory information processing, but there were no differences between the two groups on FCRT-M and KTR, tasks primarily involving motor speed. During withdrawal the patient group showed significant improvements compared to the control group on FCRT-D and STD.