Adaptive Functioning in Clients With Intellectual Disabilities or Borderline Intellectual Functioning and Psychiatric Comorbidity.

The diagnoses were copied from client files. The researchers do not know how they were actually made or whether valid assessment tools and methods were used, so some clients may be misclassified. Nothing was recorded about how severe each psychiatric disorder was, and severity is known to track with adaptive functioning in autism, so the study cannot say whether more severe illness means lower everyday functioning. This is one snapshot in time. It cannot show that a psychiatric disorder causes lower adaptive functioning, or the reverse. For depression the authors say they cannot tell whether the low IQ came before the depression, because they have no dates for the onset of depression or the IQ test. Everyone had an IQ between 40 and 99, and the sample was dominated by mild intellectual disability and borderline intellectual functioning. The results do not apply to people with average or higher IQ, or to people with severe or profound intellectual disability. An IQ score was missing for 41% of clients, so the analyses that adjust for IQ rest only on those who had one. Adaptive functioning was rated by a caregiver who knew the client. No client rated their own daily functioning. All the differences found were small in statistical terms, and most single psychiatric disorders showed no difference at all. Clients with physical or sensory impairments were excluded, so this says nothing about people whose everyday difficulties come alongside those conditions.

The work was funded by De Borg, and the paper gives no further detail about that organisation or its role. Worth knowing when weighing the results: the authors developed the ADAPT themselves and are evaluating it here, and they state that the Dutch version of the instrument is published by Hogrefe. No other competing interests are declared.

Do not conclude from this paper that psychiatric comorbidity in general drags down adaptive functioning. Only autism was associated with lower scores once gender, age and IQ were taken into account; clients with depression actually scored higher, and every other single disorder showed no difference. All the effect sizes were small. It is also a single snapshot of people already in care, so it cannot show that any psychiatric disorder causes lower adaptive functioning.