Purpose: The aim of this study was to assess the effect of withdrawal from the long-term use of temazepam, zopiclone or zolpidem as hypnotics drugs (here referred to as BZD) on cognitive performance.
Methods: Ninety-two adults (age ≥55 years) with primary insomnia and who were long-term daily users of BZD volunteered to participate in a 1-month medically supported withdrawal attempt from BZD use, with a subsequent 5-month follow-up. Withdrawal was based on plasma BZD measurements at baseline, at 1 month and during subsequent regular clinical appointments. Attention and psychomotor performance were measured using the CogniSpeed® at baseline and at 1, 2 and 6 months. Reaction times were determined in the Simple Reaction Time (SRT), Two-Choice Reaction Time (2-CRT) and Vigilance tests, and errors were measured by the 2-CRT and Vigilance tests. The cognition data of the withdrawal group were also compared with a cohort of BZD non-users.
Results: Eighty-nine (97 %) participants (59 women, 30 men) were followed-up for a maximum of 6 months. During the follow-up period, changes in reaction times and errors did not differ between short-term withdrawers (no residual BZD at 1 month; N = 69), non-withdrawers (residual BZD at 1 month; N = 20) or long-term withdrawers (N = 34). Compared to the reaction times of the BZD-free cohort, those of BZD users were slower at baseline. The reaction times of BZD withdrawers based on the results of the SRT or 2-CRT tests during follow-up did not reach those of the BZD-free cohort, but there was no difference between these groups in the Vigilance test.
Conclusions: Long-term use of BDZ as hypnotic drugs by older adults is related to prolonged impairment of attentional and psychomotor cognitive functioning that persists for at least 6 months after withdrawal.