Page 47 - Post-traumatic stress disorder in adults with mild intellectual disability: Screening, assessment, and brief intensive EMDR therapy

Reliability and validity of DITS-ID
destructive behavior” and the total number of PTSD symptoms and the
PTSD classification. There may also be explanations other than PTSD for
the presence of aggression problems. An illustrative example of another
influencing factor is frustration with basic psychological needs (autonomy,
relatedness, competence). Research indicates that individuals with MID-
BIF more frequently experience frustration with these basic psychological
needs, and this frustration is linked to the expression of externalizing
behavioral problems (Westera et al., 2023). Overall, it can be concluded that
the DITS-ID-adults is a useful instrument to classifyPTSD in people with
MID-BIF, assessing a sample of participants who were exclusively living in
residential care. Overall, it can be concluded that the DITS-ID-adults is a
reliable and valid instrument to assess PTSD in people with MID-BIF.
Reporting a potentially traumatic event (A-criterion) was associated with
fulfilling the PTSD-symptom criteria. Furthermore, people who met the PTSD
symptom criteria reported more potentially traumatic events (criterion A)
compared to those who did not meet the PTSD symptom criteria. This is in
line with the study by Mevissen et al. (2020) and underpins the cumulative
effect of trauma (Kessler et al., 2017); experiencing a potentially traumatic
event increases the likelihood of reporting more potentially traumatic
events.
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PTSD is unrecognized
Of the 97 participants, 88% had reported at least one A-criterion event
in their life, and 58% of the participants could be classified with PTSD
according to the DITS-ID-adults. This is remarkably high, as only 7% of
the participants were diagnosed with PTSD before participating in the
study. Mevissen et al. (2020) and Nieuwenhuis et al. (2019) also found
higher rates of PTSD diagnosis in their sample of participants than
the rates known in advance. These data support the notion that PTSD
is unrecognized in people with MID-BIF. Possibly because of the lack of
evidence for appropriate diagnostic tools and missing guidelines in the
field of PTSD in people with MID-BIF, diagnostic testing is rarely performed.
Another possible explanation for not recognizing PTSD in individuals with
MID-BIF is that PTSD symptoms are attributed to MID-BIF, a phenomenon
known as diagnostic overshadowing (Jopp & Keys, 2001). In addition, PTSD
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