Page 142 - Post-traumatic stress disorder in adults with mild intellectual disability: Screening, assessment, and brief intensive EMDR therapy

Chapter 6
Previous research indicates that consistent caregiver involvement is
often essential for supporting the generalisation of therapeutic gains into
everyday functioning (Farnsworth & Schröder, 2025). Limited engagement
of caregivers in Study 3 (Chapter 4) may have reduced opportunities to
translate therapeutic gains into observable improvements in adaptive
behaviour in the clients’ natural environment.
After brief intensive EMDR therapy, some participants showed small to
moderate improvement in behavioural problems. However, when looking
across all participants, no consistent pattern of decrease in behavioural
problems emerged. The use of involuntary care measures also remained
unchanged, which may be related to the fact that such measures are
typically applied in response to severe behavioural problems (Hastings
et al., 2013). Study 1 (Chapter 2) and other research (Mason-Roberts
et al., 2018; McNally et al., 2021; Rittmansberger et al., 2020) show that
PTSD and behavioural problems are associated in individuals with MID-
BIF. However, relatively little is known about how these constructs are
related and whether improvements in PTSD symptoms lead to changes in
behavioural problems. Behavioural problems in individuals with MID-BIF are
understood to be multifactorial, meaning that they arise from the interaction
of individual, environmental and neurodevelopmental factors rather than
from one of these factors alone. These factors include limited adaptive
and communicative skills, exposure to stressful or chaotic environments,
psychiatric comorbidity, and biological or neurological vulnerabilities (van
den Akker et al., 2021). Although PTSD and behavioural problems co-occur,
these broader influences mean that improvements in PTSD symptoms
alone cannot be expected to produce a uniform decrease in behavioural
problems across individuals with MID-BIF and behavioural problems. That
behavioral problems are multifactorially determined may help explain
why some participants showed small to moderate improvements, and no
consistent pattern of decrease in behavioural problems emerged across
participants in Study 3 (Chapter 4).
When interpreting the second key finding, several limitations should be
considered. First, although the randomised non-concurrent multiple
baseline design used in Study 3 (Chapter 4) provides valuable insights
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