Imagery-focused cognitive behavioral therapy techniques for auditory verbal hallucinations in psychosis spectrum disorders: Four experimental case series

Background: In psychosis spectrum disorders, maladaptive mental imagery is associated with auditory verbal hallucinations (AVHs). This study evaluates the feasibility, acceptability, and effectiveness of the following four imagery techniques in targeting mental imagery and AVHs severity: Imagery Rescripting (ImRs), Promoting positive Imagery de novo (Pos-Im), Metacognitive Imagery techniques (Meta-Im), and playing Tetris.
Study Design: Four replicated single-case series experimental designs were used. Participants were randomized to one of the four treatment conditions. Primary, we measured the severity of mental imagery and AVHs thrice daily on an 11-point VAS scale during a 2-week baseline, throughout 3 weeks of therapy, and during a 2-week follow-up phase. Randomization tests were used to examine whether daily severity levels of momentary mental imagery and AVHs decreased post-therapy. Secondary, questionnaires assessing the severity of AVHs, mental imagery characteristics, and levels of mood, anxiety and functioning were administered at baseline, before, and post-treatment.
Results: Twenty-eight participants completed all treatment sessions. Mental imagery significantly decreased after ImRs (p < .001, d = 1.13) and Pos-Im (p = .039, d = 0.22), with no significant effects observed following Meta-Im or Tetris. AVHs significantly decreased with all treatment conditions, with largest effects for ImRs (p = .001, d = 1.39) and Pos-Im (p < .001, d = 1.99). Secondary results demonstrated reductions in the severity of AVHs, mood, anxiety, imagery frequency, and appraisals.
Conclusion: Imagery techniques appear feasible and acceptable for addressing mental imagery and AVHs in the psychosis continuum and may be valuable additions to current treatment for AVHs.