Superior efficacy of cognitive-behavioral therapy for urban crack cocaine abusers: main and matching effects

This study evaluated the efficacy of cognitive-behavioral therapy (CBT) and 12-step facilitation (12SF) in treating cocaine abuse. Participants (N = 128) were randomly assigned to treatment conditions and assessed at baseline and at Weeks 4, 8, 12, and 26. Treatment lasted for 12 weeks. It was hypothesized that participants treated with CBT would be significantly more likely to achieve abstinence from cocaine than participants treated with 12SF. A series of patient-treatment matching hypotheses was also proposed. Across 2 different outcome variables, it was found that participants in CBT were significantly more likely to achieve abstinence than participants in 12SF. In addition, some support for matching hypotheses was found, suggesting that both psychotherapies may be differentially effective for identified subgroups of persons that abuse cocaine.     

Tolerance to morphine in the rat: Associative and nonassociative effects.

Two experiments were conducted to examine the impact of dose level and interdose interval (IDI) on the development of tolerance to the analgesic effect of morphine. In Exp I, rats were administered a series of low- (5 mg/kg) or high- (30 mg/kg) dose injections of morphine either explicitly paired or unpaired with a distinctive context at a 48-hr IDI. The development of tolerance following this regimen was assessed by shifts in dose-response curves to the right when animals were tested on a tail-flick device in the distinctive context. Only animals that had received morphine paired with the distinctive context were tolerant to morphine; the magnitude of this associative tolerance was a positive function of the level of the conditioning dose. In Exp II, rats were exposed to a high dose of morphine (30 mg/kg) either paired or unpaired with a distinctive context at one of two IDIs (24 or 96 hr). Tolerance testing revealed that at the long IDI, only associative tolerance was evident, whereas at the short IDI, tolerance in the unpaired condition was more pronounced with a corresponding decline in the development of associative tolerance. The relevance of these findings for psychological theories of drug tolerance are discussed. Results are consistent with the predictions of an habituation model of drug tolerance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)