The prevalence, risk and protective factors of the co-morbidity of neurodiversity and substance use.

The World Health Organization defines neurodevelopmental disorders as cognitive and behavioural conditions arising during a child's development. These include autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). ADHD involves a persistent pattern of inattention and/or hyperactivity-impulsivity, negatively affecting academic, occupational, or social functioning. ASD includes difficulties with social communication and interaction, alongside repetitive and inflexible behaviours, interests, or activities. There is a growing shift to emphasize protective factors, especially in the context of increasing co-morbidity between neurodiversity and substance use disorders.

The aim of this study is to provide the first estimates of the prevalence of neurodiversity among people accessing addiction services and to identify the risk and protective factors to inform appropriate service responses. This is a concurrent mixed method study including a systematic review on ADHD and ASD assessment among people who use substances.

A total of 11,508 articles were retrieved, of which 7,524 articles have been reviewed. One initial finding of the systematic review is the neglect of the assessment of prevalence of neurodiversity among people with substance use disorder (SUD) and the focus in the research literature of the alternative problem of SUD among people with confirmed neurodiversity. This highlights a further disparity among people who use substances. Over 500 anonymous online survey data have been gathered and qualitative interviews with key stakeholders are ongoing.

A triangulation across all the data sources will be conducted to seek areas of convergence and divergence within the results. This triangulation will enable commonalities in needs to be identified and may also highlight unexpected or discordant but important results. These final findings will inform recommendations which will be expressed as recommendations for service and practice or for policy.