An evaluation of Beck's cognitive theory of depression in adults with intellectual disability

The theories supporting cognitive treatment for depression among individuals with intellectual disability (ID) have not been formally tested with this population. The current study evaluated Beck's cognitive theory of depression to determine its appropriateness for adults with ID.

Forty-eight adults with primarily mild or moderate ID participated in semi-structured interviews, twice approximately 16 weeks apart, as did an additional 12 adults diagnosed with depression. Participants reported on depressed mood, the cognitive triad, as measured by views of the self, the world and the future, hopelessness and self-esteem.

The Cognitive Triad Inventory for Children (CTI-C) displayed adequate psychometric properties in this sample. In addition, it was correlated with depressed mood, and individuals diagnosed with depression had significantly higher scores on the CTI-C than those with no psychiatric diagnoses. Contrary to hypotheses, a negative cognitive triad did not predict depressed mood 4 months later, but the inverse relationship where depressed mood predicted a later negative cognitive triad approached statistical significance.

The findings indicate that the cognitive triad can be measured among individuals with mild or moderate ID and is related to depression and depressed mood. However, the role of the cognitive triad in the development of depression is still unknown. The findings provide some support for Beck's cognitive theory of depression among individuals with ID and provide suggestions for further testing the theory. Implications for the treatment of depression among individuals with ID are discussed.