A Cochrane review included 6 studies on adult populations with learning disabilities with a total of 309 subjects. They were based on adult populations with intellectual disabilities. These studies examined a range of cognitive-behavioural therapy (CBT) approaches: anger management (3 studies, n = 235; one individual therapy and two group-based); relaxation (one study; n = 12), mindfulness based on meditation (one study; n = 34), problem solving and assertiveness training (one study; n = 28). They were compared with standard treatment or wait-list control groups. There were no studies using behavioural interventions and no studies of children. Three studies showed some benefit of the intervention on improving anger ratings. The meta-analysis was not conducted due to the heterogeneity of studies. Follow-up data for anger ratings for both the treatment and control groups were available for 2 studies. Only one of these studies (n = 161) had adequate long-term data (10 months), which found some benefit of treatment at follow-up (continued improvement in anger coping skills as rated by key workers). Two studies (n = 192) reported some evidence that the intervention reduces the number of incidents of aggression and one study (n = 28) reported evidence that the intervention improved mental health symptoms. One study investigated the effects of the intervention on quality of life and cost of health and social care utilisation. This study suggests that compared to no treatment, behavioural or cognitive-behavioural interventions do not improve quality of life at 16 weeks (n = 129) or at 10 months follow-up (n = 140), or reduce the cost of health service utilisation (n = 133). Only one study (n = 28) assessed adaptive functioning. It reported evidence that assertiveness and problem-solving training improved adaptive behaviour. No studies reported data on adverse events.
Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in participant, interventions and outcomes), indirectness (short follow-up times) and by limitations in study quality (unclear allocation concealment).