Dosed versus prolonged exposure in the treatment of fear: an experimental evaluation and review of behavioral mechanisms.

Exposure-based treatments have proven effective in treating a range of fears and phobias and can be accounted for by mechanisms described in behavioral theory. Enhanced dosed and dosed-only exposure are promising new behavioral approaches for treating fears and phobias. Thirty-nine participants with speech anxiety were randomly assigned to a prolonged exposure (PE) condition, a positively enhanced dosed exposure (PDE) condition, a dosed-only exposure (DE) condition, or a negatively-supplemented dosed exposure (NDE) condition. Results indicated that both the PDE and DE conditions produced less measured aversive arousal and significantly more rapid arousal reduction than the tested alternatives. These techniques may represent an important advancement, in that the treatment gains of traditional exposure therapies might be achieved without the degree of aversive arousal (and possibly high drop out rates) typically seen in exposure therapies. Additionally, these data contradict prevailing opinion concerning the necessity for sustained aversive arousal during exposure-based treatment.