The relationship between challenging behaviour and anxiety in adults with intellectual disabilities: a literature review.

The authors read every paper published between 2000 and 2012 that looked at anxiety and challenging behavior in adults with intellectual disability.

They found only seven studies, so they wrote a narrative review instead of a meta-analysis.

All studies used caregiver reports or clinical interviews; none used physiological measures like heart rate.

Every study showed a moderate link: when anxiety goes up, so does challenging behavior.

Yet the link is messy. Some behaviors look like anxiety but are not labeled that way.

Because anxiety is rarely screened, many adults stay undiagnosed and behaviors are blamed on the disability itself.

Haishi et al. (2013) extends this picture by showing that cognitive slowing starts around age 30 in severe ID. Together the papers warn: as adults age, both hidden anxiety and hidden brain changes can spark behaviors that look "new" but have medical roots.

Finlayson et al. (2025) and Bouck et al. (2016) echo the same gap. Janet’s team found high rates of untreated incontinence, while C et al. showed lower quality of life; both argue that health problems stay invisible unless you actively screen.

Eggleston et al. (2018) carries the timeline further: once these adults reach 50, having four or more health conditions doubles mortality risk. The 2014 review’s call to screen for anxiety therefore feeds straight into the later life-or-death numbers seen in D et al.

If you support adults with ID, add a quick anxiety screen to your intake. Use the Glasgow Anxiety Scale or simply ask caregivers about new fears, sleep loss, or avoidance. Treating anxiety can cut challenging behavior before you write a behavior plan.