In a search of several international databases for studies published through June 2013, the authors found 34 articles describing 29 studies (including 15 randomized controlled trials) involving 1,305 participants that met their inclusion criteria. The studies evaluated behavior analytic techniques, cognitive rehabilitation, training, and support, and parent training interventions.

The authors found that for behavior analytic interventions, the best outcomes were shown for developmental and daily skills; cognitive rehabilitation, training, and support were found to be most effective for improving developmental outcomes; and parent training interventions to be most effective for improving developmental, behavioral, and family outcomes. The study limitations included that in research of this type it is difficult to mask individuals to the intervention, and therefore the studies are susceptible to performance bias, and the fact that few studies were conducted in low and middle income countries.

The authors state, "Overall, the outcomes of the studies included in this review show that non-specialist providers can deliver effective treatments to children with intellectual disabilities or lower-functioning autism spectrum disorders… Our findings that psychosocial interventions can be effective when delivered by nonspecialist providers has much relevance for improving access to care for children and adolescents with intellectual disabilities or lower-functioning autism spectrum disorders who live in both [high income countries] and [low and middle income countries], but it is useful especially in low-resource settings."

In an accompanying Perspective, Mashudat Bello-Mojeed and Muideen Bakare (Federal Neuro-Psychiatric Hospital, Lagos, Nigeria) (uninvolved in the study) discuss the implications of the study for care of children with intellectual disability or lower functioning autism spectrum disorders in low income countries. They state, "With under-five child mortality declining in resource-poor countries, an increasing number of children will live on to experience an increasing burden of neurodevelopmental disorders while the family shares a huge burden of caregiving… Interventions provided by non-specialist care providers could help alleviate the scarcity of specialist care by task shifting and potentially also help reduce the risk of burn-out among existing specialists." They conclude, "Ultimately, non-specialist psychosocial interventions for [neurodevelopmental disorders] will require advocacy and government support in [low and middle income countries], where mortality is given priority over morbidity and disability."