This paper reviews the effects of benzodiazepines (BZs) on the performance of tasks measuring human cognitive abilities. The paper reviews the most common cognitive side effects of BZs: increased sedation, decreased attention, and anterograde amnesia. In particular, this paper focuses on recent findings regarding time course-related effects on BZ-induced deficits in explicit and implicit human memory performance. Specifically, we reviewed recent research indicating that both explicit memory and priming are impaired by BZs if the encoding task takes place near the time of the theoretical peak plasma concentrations of the drug. Although BZs also appear to increase objective and subjective sedation, as well as to impair attentional processing, these other cognitive impairments do not appear to fully account for the widespread memory deficits caused by BZ administration. The theoretical and clinical implications of benzodiazepine-induced memory impairments are discussed.

Preoperative anxiety (anxiety regarding impending surgical experience) in children is a common phenomenon that has been associated with a number of negative behaviors during the surgery experience (e.g., agitation, crying, spontaneous urination, and the need for physical restraint during anesthetic induction). Preoperative anxiety has also been associated with the display of a number of maladaptive behaviors postsurgery, including postoperative pain, sleeping disturbances, parent-child conflict, and separation anxiety. For these reasons, researchers have sought out interventions to treat or prevent childhood preoperative anxiety and possibly decrease the development of negative behaviors postsurgery. Such interventions include sedative premedication, parental presence during anesthetic induction, behavioral preparation programs, music therapy, and acupuncture. The present article reviews the existing research on the various modes of intervention for preoperative anxiety in children. Clinical implications and future directions are discussed.

Purpose:To investigate the effects of midazolam on emotional reactivity during induction of anesthesia in a pediatric day surgery setting. A secondary purpose was to determine if these effects were influenced by child temperament factors. Methods: Forty children (age four to six years) scheduled for myringotomy were randomly assigned, in a double blind fashion, to receive either oral midazolam 0.5 mg·kg -1 mixed with acetaminophen suspension or acetaminophen alone. The Emotionality, Activity, Sociability, and Impulsivity (EASI) scale was used as a measure of child temperament. The modified Yale Preoperative Anxiety Scale (m-YPAS), an observer-rated measure of state anxiety, was employed to assess anxiety preand post-drug, and also at induction of anesthesia. Results: Children who received midazolam reacted significantly less to induction of anesthesia than did children in the placebo control group, F (1, 38) = 7.46, P = 0.01. A significant positive association was observed between baseline levels of anxiety and observer-rated anxiety at anesthetic induction, but only in the placebo group, r = 0.58, P < 0.01. A significant positive association was observed between levels of impulsivity at baseline and observer-rated anxiety at anesthetic induction, but only in the midazolam group, r = 0.42, P < 0.05. Conclusions: Midazolam dampened adverse reactivity during anesthetic induction, particularly among children with high baseline levels of anxiety. Baseline level of impulsivity was positively associated with adverse reactions to anesthesia induction in the drug group, but not in the placebo group, suggesting that high levels of trait impulsivity may contraindicate the use of midazolam as a preoperative medication. Objectif

No abstract

Overall, it appears that benzodiazepines do impair memory in a pediatric population. This amnesia was not secondary to the inattention and sedation also caused by midazolam administration. The theoretical and clinical implications of these findings are discussed, as are potential future studies.

Overall, it appears that midazolam induces a dissociation between explicit and implicit memory in young children in the pediatric surgery setting. Theoretical and clinical implications of the findings are discussed along with directions for future research.

Until recently, research indicated that all benzodiazepines impair explicit memory, while only lorazepam impairs priming. Stewart and associates provided preliminary data which indicated that both oxazepam and lorazepam may impair implicit memory, but in a time-dependent fashion. The present study was designed to replicate Stewart et al.'s findings after overcoming several limitations of the original study. Thirty subjects were administered an acute dose of lorazepam (2 mg), oxazepam (30 mg) or a placebo and were tested with an implicit (word-stem completion) test and an explicit (cued recall) test. However, subjects were only tested at 170 min post-drug (close to oxazepam's theoretical peak concentration) to rule out the possible "explicit memory contamination" explanation of the Stewart et al. implicit memory findings. Consistent with previous research, both drugs impaired explicit memory relative to placebo. Also, both lorazepam and oxazepam impaired priming performance, supporting the "time-dependence" interpretation of the Stewart et al. findings. The results also indicate that episodic memory is impaired by both benzodiazepines in a time-dependent fashion even when the research methodology used involves everyday memory demands.

The present study was designed to examine the effects of oxazepam on implicit vs explicit memory processes, as a function of this drug's time course. The effects of oxazepam (30 mg) or placebo on directly comparable tests of implicit memory (word stem completion) and explicit memory (cued recall) were examined at three time points: 100 min post-drug administration (prior to the theoretical peak plasma concentration of oxazepam; i.e.'pre-peak' condition), 170 min post-drug (close to theoretical peak; i.e. 'peak' condition) or 240 min post-drug (following theoretical peak: i.e. 'post-peak' condition). Sixty healthy volunteers were randomly assigned to either the drug condition or the placebo condition in a double-blind design and were tested on both memory tests at one of the three time points. In the 'pre-peak' condition, oxazepam impaired cued recall performance relative to placebo but did not impair priming. In the 'peak' condition, oxazepam impaired performance on both memory tasks. In the 'post-peak' condition, cued recall performance in the oxazepam group remained significantly impaired relative to placebo. However, oxazepam-induced impairments in priming were only marginal, suggesting that oxazepam-induced impairments in implicit memory processes begin to wane following theoretical peak drug concentrations. The fact that oxazepam-induced priming impairments were significant only when the word stem completion task was administered close to peak plasma concentrations, supports the hypothesis that benzodiazepines exert time-dependent effects on implicit memory processes. The results also support the theoretical distinction between implicit and explicit memory processes, since the directly comparable implicit and explicit tasks showed different impairment curves over time.