Cognition and Vigilance: Differential Effects of Diazepam and Buspirone on Memory and Psychomotor Performance

Abstract

Effects of a single dose of the anxiolytic buspirone (15 mg) on memory and psychomotor performance were studied in healthy volunteers and compared to those of the classic benzodiazepine anxiolytic diazepam (15 mg). The study was performed in a double-blind, placebo-controlled way. Three groups of 12 subjects were exposed to an extended test battery before and after intake of drug or placebo. Next to this, an evaluation session took place 1 week later. Immediately after intake, diazepam exerted major effects on memory, impaired psychomotor performance and decreased alterness. In particular, long-term memory had deteriorated, which was interpreted as anterograde amnesia. One week later, more items were recalled from the predrug session compared to the number of items from the postdrug session; this was interpreted as retrograde facilitation. After intake of buspirone, there were no effects of altertness and vigilance, on psychomotor performance and on memory. One week later, a small memory decrement was noticed for verbal material, which was considered as a sign of anterograde amnesia. These results indicate that effects of anxiolytics on memory can be more easily demonstrated 1 week later than immediately after drug intake and, furthermore, that the disruptive effects of diazepam outweigh the small effects of buspirone. Finally, it was established that the effects of diazepam on cognition might be mediated by its effects on alertness and vigilance and that cognitive effects are not related to the anxiolytic properties of the drug.

Effects of Diazepam and Buspirone on Reaction Time of Saccadic Eye Movements

“…In all cases almost no changes after buspi rone intake were found. It is suggested that the commonly reported cognitive deterioration of diazepam is due to its hypnotic and sedative actions [27], which is in line with others [21,22,[24][25][26]30]. In short, it is proposed here that the effects of diazepam on saccadic eye movements are due to its sedative and hypnotic properties.…”

“…Buspirone lacks the hypnotic and sedative properties of the benzodiazepines. It does not influence vigilance, while memory impairments and changes in motor per formance are minimal [24][25][26][27]. The aim of the present experiment is to establish and compare the influence of the two anxiolytic drugs diazepam and buspirone on the disengagement of attention, measured by differences in SRT in the gap and overlap conditions.…”

Amnesia after Diazepam Infusion into Basolateral But Not Central Amygdala of Rattus norvegicus

“…Further more, amnestic effects of diazepam were also demon strated using a procedure that does not employ painful stimulation [30], Administration of benzodiazepine prior to training is more effective than the posttraining administration in inducing memory impairment [28,29,31,35]. In fact, there is evidence that diazepam can even produce retro grade facilitation of memory [29,36,37] (although, using a habituation task, posttrial administration of diazepam was found to be amnestic [38]). …”

Do animal models of anxiety predict anxiolytic-like effects of antidepressants?

“…The difference between BDZs and SSRIs in treating GAD or PD is that the former have a faster onset of therapeutic action than antidepressants (Klein et al 1995;Rickels and Schweizer 1998), while antidepressants, according to some authors, could be more effective than BDZs Tyrer et al 1988;Balestrieri et al 1989;Boyer 1993;Kent et al 1998). In addition, there is increasing evidence of development of dependency following chronic BDZ treatment with withdrawal symptoms after abrupt cessation, as well as cognitive impairment in long-term BDZ users (Unrug-Neervoort 1992;Baldessarini 1996a;O'Brien 1996;Stewart et al 1996;Gray et al 1999;Mintzer and Griffiths 1999;Moore and O'Keeffe 1999;O'Neill et al 2000).…”