Cognitive dysfunction and psychopathology: a cohort study of adults with intellectual developmental disorder.
Slower processing speed and longer hospital stays signal stronger mental-health needs in adults with IDD and autism.
01Research in Context
What this study did
Wilson et al. (2023) tracked adults with both intellectual disability and autism. They gave each person the WAIS-IV and the Trail Making Test. They also recorded how long each adult had stayed in hospital.
The team wanted to know if slower thinking scores matched more mental-health symptoms. They also asked if longer hospital stays predicted worse scores.
What they found
Adults with IDD plus autism scored lower on Processing Speed and Perceptual Reasoning. They also took longer to finish the Trail Making Test.
People who had spent more time in hospital showed weaker executive skills on the same test.
How this fits with other research
Older studies like Chaplin et al. (2010) and Fullana et al. (2007) already showed that adults with ID often have depression or anxiety. Wilson et al. (2023) moves the field forward by linking those mood problems to real test numbers you can measure in an office visit.
Su et al. (2008) found that verbal memory predicts daily living skills. The new data say Processing Speed and Perceptual Reasoning predict mental-health load. Together, the papers show that any cognitive score you pick gives unique clinical clues beyond IQ.
Lecavalier et al. (2006) looked at kids and found family stress predicted later psychopathology. That seems to clash with the adult findings, but the two studies simply focus on different age groups. Family factors matter for children; processing speed matters for adults.
Why it matters
If you assess an adult with IDD and autism, add the WAIS-IV PSI and PRI plus Trail Making A and B. Low scores plus long hospital history flag higher risk for mood or behavior issues. You can use these numbers to justify more mental-health supports or shorter reassessment intervals.
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02At a glance
03Original abstract
BACKGROUND: Cognitive impairment of intellectual developmental disorders (IDD) is determined by several different combinations of specific cognitive alterations. People with IDD present a rate of mental health problems that is up to 4 times higher than that of the general population. Despite this, the relationship between specific cognitive dysfunctions and co-occurring mental disorders has not been adequately studied. The aim of the present paper is to investigate the association between specific cognitive dysfunctions and specific psychiatric symptoms and syndromes in people with IDD. METHODS: One hundred and twenty adults with mild to moderate IDD living in residential facilities underwent a clinical and instrumental assessment for specific cognitive and psychopathological features. RESULTS: Participants with IDD and ASD have significantly lower scores compared to those without respect to who has not the diagnosis on the Processing Speed Index (PSI) and Perceptual Reasoning Index (PRI) on the WAIS-IV and higher time scores on the TMT A. Moreover, there is a significant association between years of hospitalisation and TMT B and TMT B A time scores; the longer a participant with IDD was hospitalised, the worse their performance on the TMT. Although not statistically significant, many psychopathological clusters showed substantial cognitive profiles. CONCLUSIONS: Although further research is needed, neuropsychological and IQ tests scores seem to be differently associated to various psychopathological conditions co-occurring with IDD, and with ASD especially. Cognitive assessment seems to support diagnosis and treatment of psychopathological co-occurrences in persons with IDD, also in consideration of indirect implications including a better knowledge of the patient's characteristics beyond IQ deficit.
Journal of intellectual disability research : JIDR, 2023 · doi:10.1111/jir.13077