Neuropsychological performance of a patient suspected of dementia taking lorazepam and retested 1 year later following titration.

The effects of medication on neuropsychological performance have yet to be fully investigated, particularly in older patients. As such, the present case study was undertaken to examine the specific impact of benzodiazepine use on neuropsychological performance by providing a comparison of the test-retest data of an 81-year-old patient taking lorazepam. A comprehensive neuropsychological evaluation was conducted: (a) during the initial referral, while the patient had been taking high doses of lorazepam for approximately 3 years; and (b) 6 months after complete titration, which was 1 year after the initial evaluation. Normative scores derived from the 2 trials were compared via calculation of Reliable Change Indexes. Neuropsychological performance during both evaluations was indicative of dementia, including similar degrees of impairment in delayed memory, verbal fluency, and olfaction. However, scores obtained during the second evaluation were somewhat higher, with significant improvements observed in immediate memory, visuospatial/construction abilities, language function, abstract concept formation, and set shifting. Results of the current case study suggest that several neuropsychological domains may be particularly sensitive to chronic benzodiazepine use. Although the overall diagnostic picture in the present study remained unaltered, clinicians should be cognizant of such medication effects and the potential for these neuropsychological alterations to obscure differential diagnosis.