Innovation in the treatment of Dissociative Identity Disorder: The application of schema therapy.

Patients suffering from Dissociative Identity Disorder (DID) were found to have the highest psychiatric treatment costs among patients receiving medical care. There are no consensus treatment guidelines for dissociative disorders and current clinical practice entails lengthy treatment with a high dropout rate. In the current proposal, the efficacy of an alternative treatment for DID (i.e., schema therapy) is tested. Due to the rarity of the disorder and the lengthy treatment of these patients, a case series experimental approach will be used (non-concurrent multiple baseline design). Ten DID outpatients will be included from several community mental health institutes in the Netherlands. A process-measure of dissociative symptoms will be included as index of change. Additionally, various pre-, post-, and follow-up measures will be included encompassing an assessment of the presence of DID, trait dissociative symptoms, comorbid symptomatology, and global symptomatic distress.

Investigate the efficacy of schema therapy in Dissociative Identity Disorder

Multicenter, non-concurrent multiple baseline design. Patients are randomly assigned to one of the predetermined baseline lengths. Baseline observations are carried out, and after an education phase, the treatment is implemented.

Timepoints: Process measure weekly during baseline and education phase, pther measures before and after baseline period, after education phase, each 6 months during intervention, at the end of the intervention and at follow up (six months after the end of treatment).

Additional baseline measures SCID I and II, CTQ.

An additional follow-up assessment will be included one year after the end of treatment (i.e., 6 months after the end of the booster sessions).

Treatment will consist of two individual sessions a week during the first two years, followed by one individual session a week during the third year, with each session lasting 50 minutes. The treatment will be theoretically consistent with the model described in Young, Klosko, and Weishaar (2003), which was expanded for the treatment of BPD patients (van Genderen & Arntz 2010; Farrell & Shaw, 2012), and adapted for the specific treatment needs of DID patients (Farrell & Shaw, 2013).
Six monthly booster sessions will be included after the end of treatment.