ABA Outside the Spectrum: A Systematic Literature Review

Applied behavior analysis (ABA) is well known to be an empirically approved intervention for individuals with autism spectrum disorder (ASD). However, its application extends well beyond autism and developmental disabilities. Despite this broader relevance, the use of ABA within mental health contexts remains underrepresented and poorly synthesised in the literature. This systematic literature review focuses on application of ABA principles and interventions in mental health populations, excluding individuals with autism spectrum disorder or primary cognitive delays. A total of 27 peer-reviewed experimental studies published between 1970 and 2023 were included. Articles were analysed across multiple dimensions, including participant age and diagnosis, treatment setting, intervention type, dependent variables, outcomes, and evidence of generalisation and maintenance. The literature reviewed included a range of mental health diagnoses ranging from depression, substance use disorders, schizophrenia, bipolar disorder, and emotional and behavioural disorders and they were carried out inpatient, outpatient, school as well as laboratory settings. Findings indicate that ABA-based interventions—such as contingency management, reinforcement procedures, behavioural activation, functional analysis, and skills training—were consistently associated with reductions in challenging behaviours and increases in adaptive functioning across age groups. Importantly, several studies demonstrated the effectiveness of ABA when delivered as a complementary component within multidisciplinary treatment packages, enhancing both short-term outcomes and long-term maintenance. Though these results are encouraging, there is still limited literature with wide variation in participant attributes, intervention components, and timing of engagement. Practice implications, the limitations of current research, and future research directions are described. This review highlights the potential of ABA as a complementary, person-centred, and empirically grounded approach within mental health services, challenging the misconception that its utility is confined to autism-related interventions.