Asymmetrical cross‐generalization in drug discrimination with lorazepam and pentobarbital training conditions

Depressants have been characterized as showing lower specificity as training drugs than drugs from other pharmacological groups, because drug–lever responding has been occasioned by drugs that are very diverse. In contrast, recent work with lorazepam as a training drug under a food‐maintained drug vs. no‐drug discrimination procedure found unreliable pentobarbital generalization, although pentobarbital‐trained animals showed generalization to lorazepam. Exploration of the limits of this asymmetrical cross‐generalization has included manipulation of species and training doses and studies with a variety of classic and novel sedative‐anxiolytic drugs. To date, comparison of lorazepam to other benzodiazepines used as training drugs suggests that the lorazepam training condition appears to result in a lower probability of generalization to other sedative/anxiolytic drugs than other benzodiazepine training conditions. Review of drug discrimination studies with sedative/anxiolytic drugs suggests that there may be more specificity among the depressants as training drugs than initially appeared to be the case.