Addition of the SUPPORT Coach in PTSD treatment

INTERVENTION: The intervention group receives access to the SUPPORT Coach, a mobile application aiming to help people better understand and self‐manage their PTSD symptoms. The SUPPORT Coach includes psychoeducation, a self‐test with a monitoring feature, and, most importantly, various exercises and tools to cope with PTSD symptoms. Examples are deep breathing, progressive muscle relaxation, and positive imagination exercises (www.amc.nl/supportcoach). CONDITION: Trauma related complaints (e.g. anxiety, depression), Post‐Traumatic Stress Disorder (PTSD), Posttraumatic stress symptoms ; ; PRIMARY OUTCOME: Potential improvement of trauma‐focused therapy: Does usage of the SUPPORT Coach app in‐between treatment sessions potentially enhance the efficacy of traditional trauma‐focused therapy in terms of PTSD symptom reduction? Measured by the difference in PCL‐5 score reduction (continuous) between the intervention‐ and control condition at the start of therapysession 6 and 13 of the traumafocused psychotherapy. SECONDARY OUTCOME: Feasibility and acceptance of the SUPPORT Coach app as an adjunct to traditional trauma‐focused psychotherapy. Are patients willing to use the SUPPORT Coach as an additional tool in between therapy sessions? How often would they use the app and are they able to use the app on their own INCLUSION CRITERIA: • Adults, minimum 18 years of age • Referred to a mental health care institute for traumafocused psychotherapy for PTSD following one or more traumatic experiences • Meet the DSM‐5 diagnostic criteria for PTSD as confirmed by the CAPS‐5 • In possession of a mobile phone working on ANDROID/IOS operating systems • Have sufficient understanding of the Dutch language (speaking, writing, listening)