Chapter 3


Diagnosing Autism Spectrum Disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD) in both children and adults requires a comprehensive assessment by experienced healthcare professionals in Australia. The diagnostic process typically involves multiple steps to accurately identify and differentiate these conditions from other possible causes of the presenting symptoms.

For ADHD, the diagnostic process usually includes:

  1. Initial concerns: Parents, teachers, or the individual themselves may notice developmental delays, communication difficulties, or atypical social interactions that raise suspicion of ADHD.
  2. GP consultation: A visit to the General Practitioner (GP) is the first step, where concerns are discussed, and an initial evaluation is conducted. If the GP suspects ADHD, they will provide a referral to a specialist or a multidisciplinary team.
  3. Specialist assessment: A thorough assessment by a specialist, such as a paediatrician, psychiatrist, or clinical psychologist, is crucial. They will use standardised diagnostic tools and gather information from multiple sources, including interviews, observations, and reports from parents, teachers, and other professionals involved in the individual’s care.
  4. Rule out other conditions: For ADHD, the specialist will also consider and rule out other possible causes for the symptoms, such as learning disabilities, sleep disorders, or anxiety.
  5. Diagnosis and support planning: If the specialist confirms an ADHD diagnosis, they will discuss the results with the individual and their family, provide recommendations for support services and interventions, provide recommendations for treatment options (e.g., medication, behavioural therapy, and educational support) and collaborate with other healthcare professionals to create a tailored care plan.

In Australia, the diagnostic process for both ASD and ADHD must adhere to the guidelines provided by the National Health and Medical Research Council (NHMRC) and the Royal Australian and New Zealand College of Psychiatrists (RANZCP). It is crucial to obtain an accurate diagnosis to access appropriate support and interventions that can improve the individual’s quality of life.

For Adult ADHD screening, we recommend the ADHD psychology clinic and to have a chat with your GP as soon as possible.

Subsections of Diagnosis

Diagnostics Criteria

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), provides guidelines for diagnosing ADHD.

Criteria include the presence of a persistent pattern of inattention and/or hyperactivity-impulsivity, symptoms that began before age 12, impairment in multiple settings, and exclusion of other mental disorders that could better explain the symptoms.

Assessment Tools

Various assessment tools are used to support ADHD diagnosis, including rating scales, questionnaires, and clinical interviews.

These instruments gather information from multiple sources, such as parents, teachers, and the individuals themselves, to provide a comprehensive understanding of the individual’s symptoms and functioning.

Professional Evaluation

A thorough professional evaluation by a qualified clinician, such as a psychologist, psychiatrist, or pediatrician, is necessary for an accurate ADHD diagnosis.

The evaluation process typically involves gathering information on the individual’s medical, developmental, and family history, as well as conducting a thorough assessment of their cognitive, emotional, and behavioural functioning.