Psychiatric Assessment

Bias in assessment of co-occurring mental disorder in individuals with intellectual disabilities: Theoretical perspectives and implications for clinical practice

“…This vulnerability is likely to vary with the degree of intellectual disability, as the ambiguity of symptom presentations is further increased in individuals with severe intellectual disabilities and/or limited verbal language skills, compared to those with mild or moderate intellectual disabilities ( Deb et al, 2022 ; Fletcher et al, 2017 ). Presence of co-occurring conditions such as epilepsy, sensory impairment, and ASD may further increase challenges in interpreting and differentiating behavioural symptom manifestations ( Bakken et al, 2016 ; Deb et al, 2022 ; Fletcher et al, 2017 ; Helverschou et al, 2011 ; Kildahl et al, 2019b ; Morrison and Gillig, 2012 ; Siegel et al, 2020 ), thereby further increasing the potential influence of cognitive bias.…”

“…Numerous papers and book chapters have described the strategies used for mental health assessment in individuals with intellectual disabilities (e.g. Bakken et al, 2016 ; Bertelli and Moss, 2022 ; Dagnan and Lindsay, 2012 ; Deb et al, 2022 ; Helverschou et al, 2011 , 2020 ; Man and Kangas, 2020 ; Morrison and Gillig, 2012 ; Siegel et al, 2020 ; Underwood et al, 2011 , 2015 ). While multi-method strategies are often emphasised, the risk and role of potential bias in use of each of these alternative strategies has been sparsely discussed, and it is unclear how potential bias may be managed when these strategies are combined.…”

“…Individuals with intellectual disabilities are particularly susceptible to developing mental health problems ( Deb et al, 2022 ; Einfeld et al, 2011 ; Mazza et al, 2020 ; McMahon and Hatton, 2021 ; Siegel et al, 2020 ; Totsika et al, 2022 ), but mental health assessment in this population may be challenging. These individuals may have difficulties verbally communicating about their symptoms and experiences ( Bertelli and Moss, 2022 ; Dagnan and Lindsay, 2012 ; Deb et al, 2022 ; Havercamp et al, 2022 ; Man and Kangas, 2020 ; Morrison and Gillig, 2012 ; Siegel et al, 2020 ; Totsika et al, 2022 ), mental health problems may manifest in uncommon or atypical ways ( Bertelli and Moss, 2022 ; Dagnan and Lindsay, 2012 ; Helverschou et al, 2011 ; Siegel et al, 2020 ), including as “challenging” behaviours, such as aggression and self-injurious behaviours ( Bertelli and Moss, 2022 ; Deb et al, 2022 ; Emerson, 2001 ; Mevissen et al, 2016 ; Painter et al, 2018 ; Peña-Salazar et al, 2022 ; Rittmannsberger et al, 2020 ), and there is a lack of adapted assessment tools ( Dagnan and Lindsay, 2012 ; Deb et al, 2022 ; Halvorsen et al, 2022a , 2022b ; Havercamp et al, 2022 ; Helvershou et al, 2020 ; Rush et al, 2004 ; Totsika et al, 2022 ).…”

“…Due to these challenges in assessment, the strategies employed in mental health assessment in individuals with intellectual disabilities necessarily diverge from typical strategies in mental health assessment, particularly for individuals with limited verbal language skills. This includes reliance on proxy informants ( Bertelli and Moss, 2022 ; Dagnan and Lindsay, 2012 ; Deb et al, 2022 ; Emerson et al, 2013 ; Helverschou et al, 2020 ; Man and Kangas, 2020 ; Rush et al, 2004 ; Siegel et al, 2020 ), direct clinical observation ( Dagnan and Lindsay, 2012 ; Deb et al, 2022 ; Morrison and Gillig, 2012 ; Rush et al, 2004 ; Valdovinos et al, 2019 ), and use of assessment tools with unclear psychometric properties ( Dagnan and Lindsay, 2012 ; Halvorsen et al, 2022a , 2022b ; Helverschou et al, 2020 ). Obtaining a comprehensive medical and developmental history is considered a critical part of these assessments ( Bertelli and Moss, 2022 ; Dalhaug et al, 2022 ; Deb et al, 2022 ; Helverschou et al, 2020 ; Man and Kangas, 2020 ; Morrison and Gillig, 2012 ; Rush et al, 2004 ), but neither medical charts and records nor retrospective reports by caregivers are necessarily reliable or sufficiently informative ( Dagnan and Lindsay, 2012 ; Fusar-Poli et al, 2017 ).…”

“…This includes reliance on proxy informants ( Bertelli and Moss, 2022 ; Dagnan and Lindsay, 2012 ; Deb et al, 2022 ; Emerson et al, 2013 ; Helverschou et al, 2020 ; Man and Kangas, 2020 ; Rush et al, 2004 ; Siegel et al, 2020 ), direct clinical observation ( Dagnan and Lindsay, 2012 ; Deb et al, 2022 ; Morrison and Gillig, 2012 ; Rush et al, 2004 ; Valdovinos et al, 2019 ), and use of assessment tools with unclear psychometric properties ( Dagnan and Lindsay, 2012 ; Halvorsen et al, 2022a , 2022b ; Helverschou et al, 2020 ). Obtaining a comprehensive medical and developmental history is considered a critical part of these assessments ( Bertelli and Moss, 2022 ; Dalhaug et al, 2022 ; Deb et al, 2022 ; Helverschou et al, 2020 ; Man and Kangas, 2020 ; Morrison and Gillig, 2012 ; Rush et al, 2004 ), but neither medical charts and records nor retrospective reports by caregivers are necessarily reliable or sufficiently informative ( Dagnan and Lindsay, 2012 ; Fusar-Poli et al, 2017 ). Furthermore, in contrast to patients in the general population, individuals with intellectual disabilities may not be able to verbally add to or correct information obtained from clinical records, nor provide their own accounts of symptom development and treatment history.…”