Fifty-seven chronic agoraphobic outpatients were treated by 12 hours of exposure in vivo on four days over two weeks to check the effects of oral diazepam versus placebo during group exposure, group versus individual exposure, and high versus medium anxiety arousal during individual exposure. The controlled parallel design allowed comparative evaluation of each treatment condition to six months follow-up. Assessment was blind with respect to drug and psychological treatment. Patients in all treatment conditions improved significantly in phobias and in related life areas.
Outcome to group exposure on phobias and other measures was similar in all three drug conditions (placebo, waning diazepam, peak diazepam) with no significant differences between them. Diazepam patients had significantly less discomfort than placebo patients during group exposure treatment. Group exposure patients improved slightly but significantly more than individual exposure patients on non-phobic measures, though group exposure was accompanied by more panics during treatment yet was easier to run by the therapist. Individual exposure under high anxiety arousal was no more therapeutic than with lower anxiety. Diazepam is a mild palliative during group exposure but does not facilitate outcome to treatment. Group exposure in vivo is mildly facilitatory for outcome compared with individual exposure. Anxiety evocation during treatment was not therapeutically helpful.