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How Many Symptoms Are Needed for Diagnosis? 

PostedOctober 13, 2025
UpdatedOctober 13, 2025
ByMy Patient Advice
Author: Avery Lombardi, MSc | Reviewed by: Dr. Rebecca Fernandez, MBBS

Understanding the ADHD diagnostic criteria symptoms is key to knowing when a full assessment might be necessary. According to the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition), the number of symptoms required for an ADHD diagnosis depends on the individual’s age and the type of ADHD being assessed inattentive, hyperactive-impulsive, or combined type. 

For children (up to age 16), at least six symptoms of inattention and/or hyperactivity-impulsivity must be present. These symptoms must have persisted for at least six months and be inconsistent with the child’s developmental level. For adults and adolescents aged 17 and older, the threshold is slightly lower, five symptoms in either category is enough to meet the criteria. 

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Key DSM-5 Symptom Thresholds for ADHD Diagnosis 

Here’s a breakdown of how ADHD diagnostic criteria symptoms is assessed: 

Inattention Symptoms  

Examples include difficulty sustaining attention, being easily distracted, often forgetting daily tasks, or frequently losing things. 

Hyperactivity-Impulsivity Symptoms  

May include fidgeting, talking excessively, difficulty waiting turns, or interrupting others. 

Symptom Thresholds 

Children: 6+ symptoms in one or both categories 

Adolescents/Adults: 5+ symptoms in one or both categories 

In all cases, symptoms must also: 

  • Be present in two or more settings (e.g., home, school, work) 
  • Clearly interfere with functioning 
  • Have started before age 12 

In conclusion, understanding these DSM-5 guidelines helps clarify when a formal diagnosis is appropriate. 

Visit providers like ADHD Certify for personal consultations and expert guidance tailored to your unique situation. 

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to Signs, Symptoms, and Self-identification of ADHD.  

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Avery Lombardi, MSc, author for my patient advice - mypatientadvice.co.uk
Avery Lombardi, MSc
Author

Avery Lombardi is a clinical psychologist with a Master’s in Clinical Psychology and a Bachelor’s in Psychology. She has professional experience in psychological assessment, evidence-based therapy, and research, working with both child and adult populations. Avery has provided clinical services in hospital, educational, and community settings, delivering interventions such as CBT, DBT, and tailored treatment plans for conditions including anxiety, depression, and developmental disorders. She has also contributed to research on self-stigma, self-esteem, and medication adherence in psychotic patients, and has created educational content on ADHD, treatment options, and daily coping strategies.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy. 

Dr. Rebecca Fernandez, MBBS, author and a reviewer for my patient advice - mypatientadvice.co.uk
Dr. Rebecca Fernandez, MBBS
Reviewer

Dr. Rebecca Fernandez is a UK-trained physician with an MBBS and experience in general surgery, cardiology, internal medicine, gynecology, intensive care, and emergency medicine. She has managed critically ill patients, stabilised acute trauma cases, and provided comprehensive inpatient and outpatient care. In psychiatry, Dr. Fernandez has worked with psychotic, mood, anxiety, and substance use disorders, applying evidence-based approaches such as CBT, ACT, and mindfulness-based therapies. Her skills span patient assessment, treatment planning, and the integration of digital health solutions to support mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewer's privacy.