Use of computerized neuropsychological tests (CANTAB) to assess cognitive effects of antihypertensive drugs in the elderly

Objective To establish reliability and ease of use of the Cambridge Neuropsychological Test Automated Battery (CANTAB) in assessing changes in cognitive function induced by antihypertensive drugs. Design and methods Standard neuropsychological testing was combined with CANTAB in a double-blind 18-week cross-over study in elderly hypertensives taking perindopril or hydrocholorothiazide/triamterene (HT). Cognitive effects were assessed by employing tests of attention, visuospatial and verbal memory, learning, reasoning, planning, problem solving, speed and coordination. Affect was assessed using two different depression-rating scales. Results Perindopril and the diuretic had no adverse effects on the various aspects of cognitive function. Mood, as assessed by the Hamilton Depression Rating Scale and the Beck Depression Inventory, was improved on Perindopril, and the error rate in the motor screening test was lower. Ambulatory blood pressure monitoring showed both drugs achieved effective 24-h control. Conclusions The ease of use and the ability to adjust the level of testing to the requirements of individual patients, together with the reliability of longitudinal test/re-test results, indicates that CANTAB is an important addition to the methods available to quantitate adverse central nervous system drug effects. The other purpose of the study was to assess any adverse cognitive effects of perindopril against a drug HT believed to have no adverse central nervous system effects. In this context, perindopril was free of adverse effects in all the objective tests employed. In addition, there was a benefit seen in two independent assessments of depression (the Hamilton and the Beck rating scales).