This study addressed the assumption that rate of onset affects the euphorigenic effects of drugs. Drugs with rapid onset are commonly thought to be more euphorigenic than drugs with slower onset, but this idea has rarely been studied directly. Nine healthy male social drinkers, with no history of drug- or alcohol-related problems, participated in three sessions. On each session they received oral doses of placebo (PLAC), diazepam in a rapid onset condition (FAST), or diazepam in a slow onset condition (SLOW). In the FAST condition, they received a single 20 mg dose, whereas in the SLOW condition they received six 4 mg doses administered at 30-min intervals. Plasma levels of diazepam and desmethyldiazepam, subjective effects (including measures of euphoria), psychomotor performance and vital signs were monitored throughout each session. Although the FAST and SLOW conditions led to similar peak plasma levels of drug, the peak was attained earlier in the FAST condition (61 min versus 220 min). Subjects' scores on a measure of euphoria (MBG scale of the ARCI) were significantly higher in the FAST condition compared to the SLOW and PLAC conditions. Subjects exhibited significantly more behavioral signs of intoxication and greater psychomotor impairment in the FAST condition. Sedative effects of the drug were similar in magnitude, but the effects lasted slightly longer in the FAST condition. On several measures diazepam produced similar effects in the two conditions (e.g., ratings of strength of drug effect). These data provide limited support for the notion that a faster rate of onset of drug effects is associated with greater euphoria.

No abstract

Although approximately 32% of all smoked cocaine ("crack") users are women, most studies investigating cocaine use have recruited only male subjects. Therefore, this study examined the smoked cocaine self-administration patterns of female crack abusers. A work requirement, where up to five tokens were earned by subjects, was followed by the administration of a sample delivery of one of three dose sizes [5.0 mg (placebo), 0.2 mg/kg, 0.4 mg/kg] of cocaine. The three dose sizes of cocaine were administered in counterbalanced order across subjects, with each subject receiving one dose size within a session and all dose sizes across the three experimental sessions. A self-administration phase followed the sample delivery, during which a token could be exchanged every 30 min for monetary reimbursement or a delivery of cocaine in the same dose size as the sample delivery. The results show that females' patterns of behavioral and subjective responding to smoked cocaine exhibit clear dose-related effects, thus affirming this self-administration model as safe and appropriate for use with women.

The temporal consistency of the WAIS-R Memory/Freedom from Distractibility factor and its intrafactorial components were measured over a 4-wk. period in a nonclinical sample of 22 undergraduates. A modest but significant consistency coefficient of .49 was obtained for Memory/Freedom from Distractibility. Neither intrafactorial component manifested significant temporal consistency over four weeks. Significant retest improvements were expected and observed on Memory/Freedom from Distractibility and Advanced Computation. These retest improvements were interpreted in terms of task familiarity rather than specific content recall. The reported temporal consistency coefficients appear to represent the lowest consistency for these neuropsychological constructs. The routine use of Memory/Freedom from Distractibility was questioned pending more comprehensive measurement of reliability.