Dysthymic disorder in adolescents with intellectual disability.
K-SADS reliably spots chronic mild depression in teens with ID when you ask both the teen and the parent.
01Research in Context
What this study did
Schlundt et al. (1999) ran a small case series with 12 teens who had mild intellectual disability.
They used the K-SADS interview to check for dysthymic disorder, a mild but long-lasting depression.
Both the teens and their parents answered the same questions so the team could compare answers.
What they found
The K-SADS worked: parent and teen answers matched well, showing the tool is reliable.
The symptom picture looked like that seen in younger typical-IQ kids with dysthymia.
How this fits with other research
Sisson et al. (1993) had already shown that different depression scales correlate in teens with ID, yet self- and caregiver reports often clash. G et al. echo that warning but give hope that a structured interview like K-SADS can bring the two views together.
Maïano et al. (2011) and Pellicano et al. (2022) later built on this line by adapting the shorter CES-D for the same age group. Their positive results extend G et al.’s finding: teens with ID can give valid mood data when the tool fits their needs.
Festinger et al. (1996) saw only 40 % agreement between adults with ID and their informants. The higher agreement in G et al. may look like a contradiction, but age and tool matter: teens interviewed with K-SADS can respond more reliably than adults answering a survey.
Why it matters
You no longer have to skip depression screening in teens with mild ID. Use the K-SADS or one of the later CES-D versions shown to work, and always collect both parent and youth views. When answers differ, probe further instead of picking one side.
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02At a glance
03Original abstract
The present report examines the clinical features of dysthymic disorder in a sample of adolescents with mild intellectual disability (ID). Frequency of symptoms, comorbidity, agreement between reports of subjects and parents, comparison between the frequency of depressive symptoms in subjects with ID and in two different groups of normal IQ dysthymic subjects (aged 7-11, 11 and 12-18 years) are described. The sample consisted of 12 subjects (age range = 12-25.6 years; mean age = 16.3 years) screened from unselected consecutively referred patients with mild ID. All the subjects were comprehensively diagnosed with a structured diagnostic interview, the Kiddie-Schedule for Affective Disorder and Schizophrenia (K-SADS), according to DSM-IV criteria. A symptomatic profile in the group with ID showed that intrapsychic and cognitive symptoms, such as depressed mood, irritability, pathological guilt and low self-image, were frequently reported in people with ID. Parents were less aware of depressed mood, but they reported high rates of low self-esteem; the agreement between the depressive reports of ID subjects and their parents was higher than in previous findings in normal IQ children. The symptomatic profile of subjects with ID was more comparable to that of prepubertal dysthymic children than that of dysthymic adolescents, but more significant are the analogies between dysthymic disorder in ID and normal IQ subjects. High rates of comorbidity with generalized anxiety disorder were evident in the group with ID. According to the present data, dysthymic disorder can be diagnosed in adolescents with mild ID. The K-SADS clinical interview seems to be a reliable instrument for the diagnosis and clinical definition of depressive symptomatology in this special population.
Journal of intellectual disability research : JIDR, 1999 · doi:10.1046/j.1365-2788.1999.00195.x