What are the main causes of ADHD?

PostedAugust 19, 2025

UpdatedSeptember 4, 2025

ByMy Patient Advice

Author: Avery Lombardi, MSc | Reviewed by: Dr. Rebecca Fernandez, MBBS

The causes of ADHD are multifaceted, including a mix of early brain development issues and inherited characteristics. While there’s not a single explanation, researchers agree that both genetics and environmental triggers play a significant role in shaping the condition.

A strong family history remains one of the clearest indicators, suggesting that genetics is a key part of the puzzle. However, environmental triggers such as smoking, alcohol use, or stress during pregnancy can also contribute to how ADHD develops. These factors may influence brain structure and function during key stages of early growth. Understanding the causes of ADHD can help with early identification and support.

Studies show that people with ADHD often have differences in brain areas linked to attention, impulse control, and organisation. These changes may begin during pregnancy or early childhood, further highlighting the importance of both biological and environmental factors in the ADHD causes equation.

Common Signs to Watch Out For

Recognising the signs of ADHD can help families seek support earlier. Below are some behaviours that may point to the condition:

Inattention

Children may seem easily distracted, forget instructions, or struggle to complete tasks. They often appear mentally “somewhere else” during conversations or lessons.

Impulsivity

This can involve blurting out answers, interrupting others, or making quick decisions without thinking about the consequences.

Hyperactivity

Excessive movement, fidgeting, or restlessness can become more noticeable in quiet or structured settings.

If these signs are showing up consistently, it may be time to explore professional support.

Visit providers like ADHD Certify for personal consultations and tailored guidance.

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to premature birth or low birth weight.

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

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.