When a child struggles with attention, rigid routines, and anxious behaviours all at once, it’s tempting to assume only one diagnosis can be “the real one.” In this webinar, Dr. Cheryl Gilbert MacLeod, Senior Psychologist at The Family Psychology Place, explains why ADHD, autism, anxiety, and OCD so often overlap in children and adolescents — and how to make sense of what’s actually going on.

Untangling the Overlap

• Anxiety and OCD: Anxiety disorders are the most common mental health concern in youth, with prevalence rising significantly in older adolescents. OCD was once grouped under anxiety but is now its own diagnosis — relatively rare, affecting 1–3% of the population, typically with onset between ages 8 and 12.
• ADHD: The most common neurodevelopmental disorder in youth, estimated to affect 5–9% of the population, presenting as inattentive, hyperactive, or combined type.
• Autism Spectrum Disorder (ASD): Affects roughly 2% of children aged 1 to 17, characterized by differences in social communication and the presence of repetitive behaviours, interests, or sensory sensitivities.

Why These Conditions Get Tangled Together
These diagnoses frequently coexist — 80% of children with ADHD have at least one other diagnosis, and nearly all children with anxiety have a comorbid condition — largely because they affect overlapping areas of the brain governing attention, emotion, and executive functioning. That overlap makes misdiagnosis a real risk: repetitive behaviours or avoidance can look similar across conditions, and cultural norms and gender differences further shape how symptoms present and get diagnosed.

Getting to an Accurate Picture

• The Team Approach: Diagnosis works best as a collaborative process — drawing on input from parents, teachers, and pediatricians rather than a single perspective.
• Distinguishing the Behaviours: Parents can help by observing the context, triggers, and frequency of challenging behaviours, particularly distinguishing functional routines (often ADHD) from non-functional, ritualistic behaviour (often OCD).
• Matching Treatment to Diagnosis: ADHD is often managed through behavioural interventions, routines, and sometimes medication; ASD through social skills training, psychoeducation, and behavioural therapy; anxiety and OCD through Cognitive Behavioural Therapy (CBT) and Exposure and Response Prevention (ERP).

Whatever the diagnosis (or diagnoses), the most useful shift for parents is remembering that the behaviour is the issue, not the child — de-escalating, validating emotions, and practicing co-regulation so children can eventually build the self-regulation skills themselves.