Can Thyroid Dysfunction Mimic ADHD Symptoms?

Posted September 10, 2025 Updated September 10, 2025 Author: Harriet Winslow, BSc Reviewed by: Dr. Rebecca Fernandez, MBBS

Thyroid dysfunction vs ADHD is an important distinction, as both conditions can lead to issues with attention, hyperactivity, and emotional regulation. However, the causes and symptoms of these two disorders are quite different. Understanding how thyroid dysfunction vs ADHD can overlap is key for accurate diagnosis and treatment.

Thyroid dysfunction can take two primary forms: hyperthyroidism and hypothyroidism. Hyperthyroidism, or an overactive thyroid, can cause symptoms such as restlessness, anxiety, and irritability, which can resemble the hyperactivity and impulsivity seen in ADHD. On the other hand, hypothyroidism, or an underactive thyroid, can lead to fatigue, depression, and difficulty concentrating, which can mimic the inattention often observed in ADHD.

Common Symptoms: Thyroid Dysfunction vs ADHD

Hyperthyroidism

Individuals with hyperthyroidism may experience symptoms like anxiety, irritability, and restlessness, which can be mistaken for the hyperactive behaviours seen in ADHD. However, hyperthyroidism is typically accompanied by other physical symptoms like weight loss, increased heart rate, and excessive sweating.

Hypothyroidism

Hypothyroidism can lead to attention impact, such as difficulty focusing, memory problems, and sluggish thinking, which can mimic the inattention symptoms of ADHD. However, it is often accompanied by fatigue, weight gain, and cold sensitivity, which are not typically seen in ADHD.

Attention Impact

Both conditions can affect attention, but thyroid dysfunction tends to have more physical symptoms associated with it, while ADHD is primarily characterised by long-standing behavioural patterns of inattention and impulsivity.

By recognising the differences between thyroid dysfunction vs ADHD, healthcare professionals can ensure the correct diagnosis and provide appropriate treatment for each condition.

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 Rule-outs for other conditions.

Written by

Harriet Winslow, BSc

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.

Reviewed by

Dr. Rebecca Fernandez, MBBS

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.