Snoezelen or controlled multisensory environment (MSE) is a therapy for people with autism and other developmental disabilities, dementia or brain injury. It consists of placing the person in a soothing and stimulating environment, called the "Snoezelen room". These rooms are specially designed to deliver stimuli to various senses, using lighting effects, color, sounds, music, scents, etc. The combination of different materials on a wall may be explored using tactile senses, and the floor may be adjusted to stimulate the sense of balance. The person is usually accompanied by an aide or therapist.
The term "Snoezelen" (pronounced /ˈsnuzələ(n)/) is a neologism formed from a blend of the Dutch "snuffelen" (to seek out, to explore) and "doezelen" (to doze, to snooze). "SNOEZELEN" is a registered trademark of the English company Rompa which sells equipment for Snoezelen rooms, even though the term was coined and the concept developed by Jan Hulsegge and Ad Verheul from their work at De Hartenberg Institute in the Netherlands. 
Ideally, Snoezelen is a non-directive therapy, controlled by the client and not by the therapist. It can be staged to provide a multi-sensory experience or single sensory focus, simply by adapting the lighting, atmosphere, sounds, and textures to the specific needs of the client at the time of use. There is no formal focus on therapeutic outcome - the focus is to assist users to gain the maximum pleasure from the activity in which they and the enabler are involved. An advantage of Snoezelen therapy is that it does not rely on verbal communication and may be beneficial for people with profound autism, as it may provide stimulation for those who would otherwise be almost impossible to reach.
Snoezelen therapy relates to the interdependence of both the space (the physical environment) and the "client-centered" approach of the practitioner (the human environment). The specially designed sensory physical environment together with the input of the "enabling practitioner" initiates changes in arousal by affecting the relaxation process, reducing anxiety/pain (both physical and emotional). It aims to maximize a person's potential to focus on his own free will and to engage on a motivational stimulus (object, activity or person), and thereby to improve communication and functioning.
The defining principles of the MSE help the practitioner to focus attention on the basic elements of this approach. The following are the principles.
- The experience takes place in a specific physical environment.
- The attitude of the practitioners is "client centered".
- Stimuli must be controlled according to the client's needs.
- The MSE is a medium for communication.
- The sensory environment is neither positive nor negative.
- The practitioner relies on the client's point of view. (Shapiro, 2010).
A small research study carried out in Brussels compared the behavior of nine adult clients with profound autism in both classroom and Snoezelen settings. Though individual results varied, the study claimed a 50% reduction in distress and stereotypical behavior, and seventy-five percent less aggression and self-injury in the Snoezelen environment.
- "History of Snoezelen". Snoezeleninfo.com. 2005-11-29. Retrieved 2014-11-05.
- Shapiro et al., 1997; 2009a; 2009b; Fornes, Messbauer, Pagliano & Verheul, 2009
- Chung JCC, Lai CKY. Snoezelen for dementia. The Cochrane Database of Systematic Reviews 2002, Issue 4. Art. No.: CD003152. doi:10.1002/14651858.CD003152.
- Lancioni GE, Cuvo AJ, O'Reilly MF. Snoezelen: an overview of research with people with developmental disabilities and dementia. Disabil Rehabil. 2002; 24: 175-84. PMID 11926258
- International Snoezelen Association, with definition of snoezelen, bibliography, meetings etc.
- Report on the use of a snoezelen room at Jackson Memorial Hospital, fall 2004
- Photo and video galleries of various snoezelen rooms
- Snoezelen in Israel
- Snoezelen for people with Alzheimer's and dementia