Challenging behaviors should not be considered depressive equivalents in individuals with intellectual disabilities. II. A replication study.

Sturmey et al. (2010) asked a simple question: do challenging behaviors signal depression in adults with severe or profound intellectual disability?

They re-checked the same behavioral "depression equivalents" an earlier group had proposed—things like social withdrawal, irritability, or self-injury.

Using the same tests and ratings, they looked for any link between those behaviors and formal depression scores.

No link showed up. The behaviors did not track with depression any better than chance.

The result matched an earlier null study, strengthening the evidence that these behaviors are not mood clues.

Meins (1995) first described irritability and behavior worsening in depressed adults with ID, planting the idea that behaviors might equal mood. Sturmey et al. (2010) directly tested and rejected that idea, turning an early observation into a falsified claim.

Perez et al. (2015) later tracked the same population for months. They found that falling interest or pleasure predicted later self-injury, but mood scores did not. This extends Peter’s null finding: look at enjoyment, not general mood, if you want early warning signs.

Matson et al. (2009) and Willner (2015) both reviewed drug studies and found little proof that antidepressants or antipsychotics curb challenging behaviors. Their medication doubts line up with Peter’s message—do not treat behaviors as psychiatric symptoms without stronger evidence.

If you support adults with severe or profound ID, do not assume that self-injury, withdrawal, or aggression equals depression. Treat the behavior as communication, run a functional assessment, and seek medical or psychiatric evaluation only when clear, additional signs emerge. This stance protects clients from unnecessary medication and keeps your intervention focused on environmental causes and skill building.