Combining alprazolam with systematic desensitization therapy for dental injection phobia.

To determine whether a benzodiazepine facilitates systematic desensitization, 144 subjects with dental injection phobia received systematic desensitization in combination with placebo or one of two doses of alprazolam (0.5mg or 0.75mg). Systematic desensitization therapy included computer-controlled presentation of digitized video segments followed by in vivo exposure segments, culminating in an actual dental injection. Subjects advanced to the next hierarchy segment when low anxiety was reported during a segment. Alprazolam and placebo groups progressed at the same rate. The 0.75mg group had elevated heart rates while watching video segments compared with placebo. In a subsequent behavioral avoidance test (during which subjects were randomized to a new drug condition), there was no indication that state-dependent learning had occurred. Dental fear was reduced similarly in all groups for 1 year after study completion. No advantage was found to combining alprazolam with systematic desensitization for dental injection phobia.