Behavioural Activation and Severe Learning Disabilities

This is a 38-item behavioural checklist derived from DSM-III-R criteria, designed to measure the frequency of identified depressive behaviours within a four-week period. Minimum possible score is 0 and maximum possible score is 228. Higher scores indicate a higher frequency of depressive symptoms.

This scale is the only one that has been shown to be a reliable and valid measure of anxiety in adults with severe/profound intellectual disabilities. Since the investigators are already using two measures of depressive symptoms, only the anxiety sub-scale of the Anxiety, Depression and Mood Scale will be used in this study. Seven items will be used from the original 28-item measure. These items comprise the 'generalised anxiety' subscale, with informants reporting on their observations of these symptoms in the last 2 weeks. Items are scored on a four-point Likert scale that combines frequency and severity of symptoms. Minimum possible score is 0 and maximum possible score is 42. Higher scores indicate a higher frequency and severity of anxiety symptoms.

This 16-item scale provides a measure of participation in social and community based activities during the previous 4 weeks. Minimum possible score is 0 and maximum is 80. Higher scores indicate a higher frequency of engagement in community activities.

This scale measures participation in 13 household tasks during the previous 4 weeks. Minimum possible score is 0 and maximum possible score is 26. Higher scores indicate higher levels of independent participation in domestic tasks.

This proxy report questionnaire assesses the participants' health related quality of life across five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has five levels: no problems, slight problems, moderate problems, severe problems and extreme problems. Possible minimum score is 5 and possible maximum score is 25. Higher scores indicate more problems in these domains. There is an additional visual analogue scale with endpoints of 'the worst health you can image' and 'the best health you can image' on a 0 to 100 scale.

The BPI-S is an informant-based behaviour rating instrument for adults with intellectual disabilities who display challenging behaviour. It is a 30-item measure which includes three subscales: Self-Injurious Behaviour (14 items), Stereotyped Behaviour (24 items), and Aggressive/Destructive Behaviour (11 items). This measure assesses both severity and frequency. The frequency of the BPI-S measure is rated on a 5-point Likert scale ranging from 0 (never/no problem) to 4 (hourly). The severity of the self-injurious and aggressive/destructive behaviour is rated on a 3-point Likert scale starting from 1 (mild) to 3 (severe). Possible minimum and maximum scores are 0 - 56 (self-injurious behaviours), 0 - 70 (aggressive/destructive behaviours), and 0 - 48 (stereotyped behaviours). Higher scores indicate a higher frequency and severity of problem behaviours.

This is a flexible five item scale to assess carer (parents and paid carer) perceptions of their self-efficacy in specific support domains relating to children and adults with intellectual disability or autism. Minimum possible score is 0 and maximum possible score is 80. Higher scores indicate higher perceived self-efficacy.

This seven item self-report measure of mental wellbeing has strong internal consistency (Cronbach's alpha = 0.88 - 0.93) and has proven to have good construct validity, with significant correlations with scores from other standardised measures of mental health and wellbeing, the PHQ-9 and GAD-7. The possible minimum score is 13 and possible maximum score is 65. Higher scores indicate higher levels of wellbeing.

CSRI is a validated tool to measure total package resource use and has been used in evaluations involving people with learning disabilities. It records items such as contacts with community-based primary care, other health or social services, educational services, and outpatient and inpatient attendances. Unit costs for most of these are available.

Medication use will be recorded, and any changes in use of medication over the course of the intervention and during follow-up will be noted to determine if there are treatment differences between the two arms of the study. In combination with the CSRI, medication use will also be costed.

This comprises 12 items from two subscales (mood, and interest and pleasure) and requires proxy respondents to indicate how often a particular symptom has occurred within the last 2 weeks. Possible minimum and maximum scores for each sub-scale are 0 - 24. Lower scores indicate lower mood and lower levels of interest and pleasure. The mood interest and pleasure questionnaire (Ross et al., 2008; Ross & Oliver, 2003) short form shows high internal con sistency (Cronbach alpha coefficients: total = .88; mood = .79; inter est and pleasure = .87) (Ross et al., 2008)