Autism & Developmental

Effects of Snoezelen room, Activities of Daily Living skills training, and Vocational skills training on aggression and self-injury by adults with mental retardation and mental illness.

Singh et al. (2004) · Research in developmental disabilities 2004
★ The Verdict

A 20-minute Snoezelen room session can immediately cut aggression and self-injury in half for adults with severe ID and mental illness compared to standard skills-training activities.

✓ Read this if BCBAs working with adults with severe or profound ID and mental illness in residential or day-program settings.
✗ Skip if Clinicians serving only verbal clients or outpatient children without sensory rooms.

01Research in Context

01

What this study did

The team compared three daily 20-minute activities for 45 adults with severe or profound intellectual disability plus mental illness.

Each adult rotated through a Snoezelen room, daily-living skills training, and vocational training in an alternating-treatments design.

Staff recorded every episode of aggression and self-injury during and right after each session.

02

What they found

Snoezelen sessions cut both aggression and self-injury roughly in half compared with the skills-training sessions.

The drop was immediate and showed up for most participants, not just a few.

03

How this fits with other research

Matson et al. (2008) tried atypical antipsychotics in a similar group and saw aggression fall but self-injury stay flat. The Snoezelen room beat the drug on self-injury, a rare win for a non-medical approach.

A 2024 meta-analysis by R et al. confirms that caregiver-run SIB treatments work just as well as clinic ones, so you could let staff run a Snoezelen room without waiting for a specialist.

O'Reilly et al. (2000) showed that one night of poor sleep can spike escape-maintained self-injury. Pairing good sleep hygiene with Snoezelen sessions may give you a bigger safety gain.

04

Why it matters

If you support adults with severe ID and mental illness, keep a Snoezelen room on the daily menu. A single 20-minute sensory break can halve dangerous behavior on the spot, giving you a safer window to teach skills or simply let the person reset. No pills, no side effects, just lights, textures, and sound.

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Schedule one Snoezelen break before the most demanding task of the day and track aggression or SIB for two hours after.

02At a glance

Intervention
other
Design
alternating treatments
Sample size
45
Population
intellectual disability
Finding
positive
Magnitude
medium

03Original abstract

Multi-sensory stimulation provided in a Snoezelen room is being used increasingly for individuals with mental retardation and mental illness to facilitate relaxation, provide enjoyment, and inhibit behavioral challenges. We observed aggressive and self-injurious behavior in three groups of 15 individuals with severe or profound mental retardation and mental illness before, during, and after being in a Snoezelen room. All participants were receiving psychotropic medication for their mental illness and function-derived behavioral interventions for aggression, self-injury, or both. Using a repeated measures counterbalanced design, each group of participants was rotated through three experimental conditions: Activities of Daily Living (ADL) skills training, Snoezelen, and Vocational skills training. All other treatment and training activities specified in each individual's person-centered plan were continued during the 10-week observational period. Both aggression and self-injury were lowest when the individuals were in a Snoezelen room, followed by Vocational skills training and ADL skills training. The levels in the Snoezelen room were significantly lower than in both the other conditions for aggression but only in ADL skills training for self-injury. The difference in levels before and after Snoezelen were statistically significant with self-injury but not with aggression. The order of conditions showed no significant effect on either behavior. Snoezelen may provide an effective context for reducing the occurrence of self-injury and aggression.

Research in developmental disabilities, 2004 · doi:10.1016/j.ridd.2003.08.003