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

The team gave the adults with mild or moderate intellectual disability the Cognitive Triad Inventory for Children (CTI-C). The CTI-C asks 36 yes-no questions about the self, world, and future. Staff also rated each adult’s mood and behavior. The study checked if CTI-C scores matched staff ratings of depression.

All adults lived in staffed houses or apartments. None had a formal mood disorder diagnosis. The study took place in one English county over six months.

CTI-C scores lined up well with staff depression ratings. Higher negative thoughts meant more observed sadness, sleep problems, and tearfulness. The link stayed strong even after the team controlled for IQ and daily living skills.

Internal consistency was 0.87—good for a short scale. Adults could finish the form in 10–15 minutes with minimal help.

Kooijmans et al. (2024) extends this work. They rewrote self-report items into plain language and added pictures. Comprehension jumped and answers matched carers’ views more closely. Their study shows you can make the CTI-C even easier.

van Schrojenstein Lantman-de Valk et al. (2006) came first. They tracked the same ID adults for one year and found that negative life events predicted later depression. The 2007 paper adds the missing piece: we now have a quick tool to spot the thinking part of that pathway.

Johnson et al. (1994) and Lindsay et al. (2004) echo the same message across age groups: people with mild–moderate ID can give reliable self-reports when questions are concrete and short.

You no longer have to guess if an adult with ID feels hopeless. Give the CTI-C during intake or after a major life change. A high score is a red flag for depression and a cue to start evidence-based talk or activation therapy. Keep the language simple, sit beside the client, and read each item aloud if needed. The 10-minute check can guide your next treatment step and show progress over time.