Autism spectrum disorder is a neurodevelopmental condition characterised by difficulties with reciprocal social communication, restricted interests, repetitive behaviours, and sensory difficulties. In addition to these core features autistic people are at extremely high risk of developing additional mental health difficulties. For example, between 40% to 78% of children with autism have at least one anxiety disorder, almost four times the rate observed in children without the diagnosis. In addition, rates of depression and ADHD are extremely high. Adding to this complex picture is the fact that an autistic person will often experience more than one of these additional diagnoses. Current statistical approaches to the study of the co-occurrence of mental health conditions in autism fail to consider of important associations at a symptom level both within and between conditions, potentially preventing vital insights into key problem areas which could be targeted by interventions. To address this, we plan to apply an alternative and novel approach (Network analysis) to understanding the underlying structure of co-occurring conditions in this highly complex and heterogeneous population.