O

OCD (Obsessive compulsive disorder)

A disorder whereby an individual has recurring unwanted ideas (obsessions) and a strong urge (compulsion) to relieve the obsession.

Ocular light therapy

See Lumatron and LWS.

Omega-3

Polyunsaturated fatty acids which are essential for human health, but which the body cannot produce. They are obtained from foods such as fish and nuts. These fatty acids are believed to be important for cognitive and behavioural functions.

Online communities

Online groups such as websites, forums and chatrooms, sometimes used for social communication. This type of social communication can be attractive to some people with autism.

Operant conditioning

An intervention whereby desired behaviours are reinforced through rewards and undesired behaviours are ignored or redirected.

Opiates

Any chemical or medicine derived from the opium poppy (e.g.morphine)

Opioids

Any substance which provides a reaction like that of opium or its derivatives.

Options Program

A form of intervention developed by the Option Institute in the United States, including the Son-Rise Program.

Orodispersible

Medication which comes in tablet form and which can dissolve in the mouth and are, therefore, easy to swallow.

OT (Occupational therapy)

A therapeutic treatment aimed at enabling individuals to participate in daily activities in as independent a manner as possible. Meaningful activities are used to facilitate this process.

Outcome

The effect or impact of an intervention.

Overselectivity

Focusing on one or two components of a stimulus rather than entirety of the cues which make up a stimulus.

Oxygen therapy

See HBOT.