What Are the Core Symptoms of ADHD According to DSM-5? 

The ADHD core symptoms outlined in the DSM-5 are classified into two main categories: inattention and hyperactivity-impulsivity. To receive a diagnosis of ADHD, an individual must demonstrate a persistent pattern of these symptoms that significantly interfere with daily functioning and development. These symptoms must be evident for at least six months and cause noticeable disruption in multiple settings, such as at home, school, or work. 

Inattention symptoms include difficulty maintaining focus on tasks, making careless mistakes due to lack of attention to detail, and being easily distracted by unrelated stimuli. Individuals may also struggle to follow through on instructions, fail to complete tasks, and often appear forgetful or disorganised in their daily activities. 

Hyperactivity-impulsivity symptoms involve excessive movement, fidgeting, an inability to remain seated, and difficulty waiting for one’s turn in conversations or activities. Impulsivity often manifests as interrupting others, speaking out of turn, or having trouble controlling emotions, which can result in social challenges. 

How It Helps 

Understanding the ADHD core symptoms as defined in the DSM-5 is essential for accurate diagnosis and treatment. Recognising both inattention and hyperactivity-impulsivity symptoms helps healthcare professionals differentiate ADHD from other conditions that may present similar traits. With this understanding, more effective and targeted treatment plans can be created to manage symptoms and improve overall functioning. 

Visit providers like ADHD Certify for personal consultations and expert advice tailored to your needs.   

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to DSM-5 Diagnostic Guidelines.  

Harriet Winslow, BSc

Author

Harriet Winslow is a clinical psychologist with a Bachelor’s in Clinical Psychology and extensive experience in behaviour therapy and developmental disorders. She has worked with children and adolescents with ADHD, autism spectrum disorder (ASD), learning disabilities, and behavioural challenges, providing individual and group therapy using evidence-based approaches such as CBT and DBT. Dr. Winslow has developed and implemented personalised treatment plans, conducted formal and informal assessments, and delivered crisis intervention for clients in need of urgent mental health care. Her expertise spans assessment, treatment planning, and behavioural intervention for both neurodevelopmental and mental health conditions.

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

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.