Cognitive Processing Therapy for Posttraumatic Stress Disorder in Japan: A Randomized Clinical Trial

Area of Science:

• Psychiatry
• Clinical Psychology
• Trauma Studies

Background:

• Cognitive Processing Therapy (CPT) is an established treatment for posttraumatic stress disorder (PTSD).
• Limited evidence exists regarding CPT's efficacy in East Asian populations.
• There is a need to evaluate CPT's effectiveness in non-Western clinical settings.

Purpose of the Study:

• To assess the effectiveness of CPT combined with treatment as usual (CPT-TAU) compared to waiting list with treatment as usual (WL-TAU) for PTSD outpatients in Japan.
• To determine if CPT can reduce PTSD symptoms in a Japanese medical context.

Main Methods:

• A 16-week, single-center, assessor-blinded, parallel-group randomized clinical trial was conducted.
• Adult outpatients diagnosed with PTSD were recruited from a national psychiatric referral hospital in Tokyo.
• Participants were randomized to either CPT-TAU (12 weekly sessions) or WL-TAU.

Main Results:

• The CPT-TAU group demonstrated a significant reduction in PTSD symptoms, as measured by the Clinician-Administered PTSD Scale (CAPS-5).
• CPT-TAU showed superiority across all secondary outcomes, including depression, suicidal ideation, and disability.
• The CPT-TAU group experienced a low dropout rate and no serious adverse events compared to the WL-TAU group.

Conclusions:

• CPT, when provided with treatment as usual, is effective in reducing PTSD symptoms among outpatients in a Japanese setting.
• These findings support the broader application of CPT in East Asian populations.
• The study strengthens the evidence base for CPT as a viable treatment option for PTSD globally.