Page 16 - Post-traumatic stress disorder in adults with mild intellectual disability: Screening, assessment, and brief intensive EMDR therapy

Chapter 1
approximately 50 and 70, and individuals with BIF with IQ scores between
70 and 85 (DSM-IV-TR, APA, 2000; Kaal et al., 2015). BIF does not meet
current diagnostic criteria for an ID in most countries. In the DSM-5-TR, BIF
is included under the V-code ‘Other conditions that may be a focus of clinical
attention’ and as one of the conditions that significantly affect treatment
or prognosis (APA, 2022). Individuals with BIF often experience functional
and contextual challenges similar to those with MID. Individuals with MID
and BIF are often grouped together since they share many characteristics
and support needs (Orío-Aparicio et al., 2025). Based on data from 2018,
the number of individuals with MID-BIF is estimated at 6.4% of the Dutch
population, amounting to approximately 1.1 million people (Woittiez et al.,
2019).
Mental health conditions, such as anxiety disorders, mood disorders, PTSD,
and behavioural problems are frequently reported and appear to have a
high prevalence among individuals with MID-BIF (Kildahl & Helverschou,
2024; Nieuwenhuis et al., 2019; Noel, 2018; Rittmannsberger et al., 2020;
Totsika et al., 2022; Westera et al., 2025). As a result of comorbidity, these
individuals often have intensive care needs (APA, 2022; Boat & Wu, 2015).
This dissertation focuses on individuals with MID-BIF, mental health
problems and behavioural problems, who receive intensive 24-hour care in
supported housings.
Post-traumatic stress disorder
According to the DSM-5-TR, PTSD is a mental health condition that arises
after exposure to a potentially traumatic event (Criterion A). An event
is considered potentially traumatic if it involves directly experiencing,
witnessing, or hearing about imminent death, serious injury, or sexual
violence against oneself or someone close. PTSD involves a range of
symptoms, including intrusive symptoms (PTSD cluster B), avoidance
symptoms (PTSD cluster C), negative alterations in cognition and mood
(PTSD cluster D), and alterations in arousal and reactivity (PTSD cluster
E). To be diagnosed, these symptoms must persist for at least one month
and cause significant distress or impair daily functioning, including social
or work-related activities (APA, 2022). Approximately 81% of individuals in
the Netherlands experience at least one potentially traumatic event during
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