Brief intensive EMDR therapy for PTSD in adults with mild intellectual disability or borderline intellectual functioning and behavioural problems: a multiple baseline design study

<b>Background:</b> Individuals with mild intellectual disability (MID; IQ 50-70) or borderline intellectual functioning (BIF; IQ 70-85) are at an elevated risk of post-traumatic stress disorder (PTSD), with PTSD symptoms possibly associated with behavioural problems. It is important to test the effectiveness of trauma-focused treatments, such as eye movement desensitisation and reprocessing (EMDR) therapy, for adults with MID-BIF, PTSD, and severe behavioural problems.<b>Objective:</b> To determine the safety and effectiveness of brief intensive EMDR therapy carried out by a team of rotating therapists in adults with MID-BIF, PTSD, and severe behavioural problems.<b>Methods:</b> Using a randomised non-concurrent multiple baseline between-subjects design, 11 adults with MID-BIF, PTSD, and severe behavioural problems received a maximum of 16 intensive EMDR sessions twice daily for a maximum of two weeks from six different EMDR therapists. Primary outcome measurements included severity of PTSD symptoms, PTSD diagnostic status, and adverse events. Secondary outcome measurements included the frequency and severity of behavioural problems, presence of adaptive behaviour, and the use of involuntary care. Outcome measurements were assessed at baseline, during the intervention and post-intervention phases, and at the follow-up phases, and subject to randomisation tests for statistical significance.<b>Results:</b> Intensive EMDR therapy carried out by a team of rotating therapists resulted in significant decreases in PTSD symptoms (<i>M</i>_difference = 15.84, <i>p</i> < .001) with nine of 11 participants no longer meeting the PTSD diagnostic criteria immediately following treatment and at the 9-week follow-up. Randomisation tests revealed no significant changes in adaptive behaviour, frequency, and severity of behavioural problems. Additionally, no decrease in the use of involuntary care measures was observed. One participant dropped out; no adverse events were observed.<b>Conclusions:</b> Brief intensive EMDR therapy for individuals with MID-BIF and severe behavioural problems, conducted by a team of rotating therapists, can be done safely and effectively to reduce PTSD symptoms.