Mental disorder in adults with intellectual disability. 2: The rate of behaviour disorders among a community-based population aged between 16 and 64 years

Despite the difficulty of defining behaviour disorder, most previous studie s have reported a high rate of behaviour disorders in people with intellect ual disability (ID). The aim of the present study was to establish the over all rate and types of behaviour disorders in a population-based sample of a dults with ID. The other aim was to explore the possible risk factors that are associated with the overall rate as well as different types of behaviou r disorders. One hundred and one adults with ID aged between 16 and 64 year s were randomly selected from a sample Of 246 such adults, i.e. those who w ere known to the Vale of Glamorgan Social Services Department in South Wale s, UK. Thirteen behaviour disorders were rated according to the Disability Assessment Schedule. Background data on subjects were also collected, and w ere subsequently analysed to assess the relationship between different risk factors and behaviour disorders. Sixty-one subjects (60.4%) had at least o ne behaviour disorder of any severity or frequency. Twenty-three per cent o f subjects showed aggression, 24% self-injurious behaviour, 36% temper tant rum, 26% overactivity, 29% screaming, 38% attention-seeking behaviour, 20% objectionable habits, 18% night-time disturbance and 12% Of subjects showed destructiveness, Statistically significant associations were seen between the rate of overall behaviour disorder and the use of psychotropic medicati on, and between family and group home residence. The rate of aggression was significantly associated with the use of psychotropic medication. The rate of self-injurious behaviour was significantly associated with the severity of ID, female gender and poor communication abilities. The rate of temper tantrum was significantly associated with the use of psychotropic medicatio n. Twenty-four subjects showed severe or frequent aggression, destructivene ss, self-injury or temper tantrum, and ii individuals showed real challengi ng behaviours. Severe behaviour problems were significantly associated with female gender, severity of ID, the presence of a history of epilepsy and a ttendance at day activities.