Challenging behaviours should not be considered as depressive equivalents in individuals with intellectual disability.

BACKGROUND: Depression is one of the most common forms of psychopathology in people with intellectual disability (ID). The present study evaluated the utility of an expanded assessment of psychiatric symptoms and challenging behaviours, as measured by the Clinical Behavior Checklist for Persons with Intellectual Disabilities (CBCPID). METHODS: The CBCPID was administered to 92 people with ID, 35 of whom were diagnosed with a depressive disorder. RESULTS: Item and factor analysis of the scale indicated that depression was best assessed using the core DSM-IV symptoms of depressive disorder. Challenging behaviours such as self-injury or aggression were not closely associated with depression. Short scales using the core DSM-IV symptoms of depression were highly internally consistent. There was also evidence of the validity of these scales. CONCLUSIONS: This study found no evidence that challenging behaviours were depressive equivalents in this population. The present authors conclude that the assessment of depression in people with ID should focus on the core DSM-IV symptoms of depression.

Alpha2 macroglobulin elevation without an acute phase response in depressed adults with Down's syndrome: implications.

Studies of immune function during depression in persons without intellectual disability (ID) have revealed elevated levels of alpha2 macroglobulin (alpha2M) and an acute phase protein (APP) response. Clinical observation suggests that people with Down's syndrome (DS) may have associated genetic abnormalities in their immune systems. The APP response and alpha2M changes in depressed versus non-depressed adults with DS was the subject of the present study. The serum pan-proteinase inhibitor alpha2M, and the AP proteins c-reactive protein (CRP), alpha1 antitrypsin (alpha1AT), ceruloplasmin (Cp), beta2 Macroglobulin (beta2M), transthyretin (Trans), serum amyloid protein (SAP), and albumin (Alb) were measured in 38 adults with DS, 19 of whom were diagnosed with and 19 without depression using a sandwich enzyme-linked immunosorbent assay (ELISA). The DSM-IV criteria were used for diagnoses. Medical and neurological examinations excluded medical disorders associated with APP response. Only alpha2M and CRP were significantly different in the depressed versus non-depressed groups. The alpha2M was higher, a response similar to one observed in depressed people without ID, but the CRP was lower in the depressed group, especially in those subjects not on psychotropic medications, contrary to the expected APP response to depression. The results suggest that alpha2M elevation in depressed adults with DS is independent of the APP response. An alternative explanation for its elevation is proposed linking the core symptom of depression with the mammalian dormancy/hibernation process. Further studies are needed to confirm that alpha2M elevation is specific to depression and that it might provide a helpful marker for the diagnosis of depression in people with ID.