When evaluating patients for attention-deficit hyperactivity disorder (ADHD) it is typical to use multiple stages of assessment prior to formal diagnosis. Following assessment, formal diagnosis is based on symptoms. At Brain Therapy Centre, we use a 3-stage assessment process. The first stage is a consultation, where the psychologist will gather information about the person’s symptoms. This will also usually involve the client or parents completing a questionnaire to determine the severity of symptoms. The second stage involves assessment of cognitive skills using a brief, computerised cognitive test battery to confirm the presence of attentional difficulties. Our assessment tools are well established, reliable, objective and supported by research. The final stage involves reviewing the assessment and interview findings to confirm a formal diagnosis. ADHD assessment can be useful for both children and adults.