How common is bipolar disorder in people with ADHD

PostedNovember 20, 2025

UpdatedNovember 21, 2025

ByMy Patient Advice

Author: Harriet Winslow, BSc | Reviewed by: Dr. Rebecca Fernandez, MBBS

Bipolar disorder is more common in adults with ADHD than in the general population, and the two often overlap in ways that make diagnosis and treatment complex. According to NHS guidance and NICE guidelines, understanding this comorbidity is crucial to avoid misdiagnosis and ensure safe, effective management.

Epidemiology and comorbidity

Recent studies show that ADHD and bipolar disorder co-occur in around 9 to 36 per cent of adults, a rate far higher than expected by chance. UK data estimate that approximately 1.7 per cent of adults have bipolar disorder and between 2 and 6 per cent have ADHD. Reports from the NHS England ADHD Taskforce and the Royal College of Psychiatrists suggest that bipolar symptoms appear in about 15 per cent of adults assessed for complex ADHD presentations.

Diagnostic guidance and clinical challenges

The NICE NG87 ADHD guideline highlights the difficulty in distinguishing ADHD from bipolar disorder because both can involve impulsivity, emotional instability, and sleep disturbance. Clinicians are advised to take a detailed developmental and collateral history and to confirm whether mood changes are persistent or episodic. In most cases, bipolar disorder should be stabilised first using mood stabilisers or antipsychotics before introducing stimulant medication for ADHD. This reduces the risk of triggering manic episodes.

Neurobiological and genetic overlaps

Both disorders share genetic and neurobiological links, particularly involving dopamine and prefrontal cortex function. A PubMed review found that these shared mechanisms may explain why impulsivity, poor emotional regulation, and fluctuating energy levels are common to both conditions. Research also indicates that individuals with ADHD and bipolar type II often experience earlier onset, higher emotional reactivity, and more frequent mood episodes than those with either condition alone.

Treatment and monitoring when both coexist

The NICE bipolar guideline (CG185) and NICE NG87 recommend starting with mood stabilisers such as lithium or valproate before considering ADHD medication. If stimulants are used, this should only occur once the mood is stable and under close supervision. Antidepressants are prescribed cautiously, as they can trigger manic episodes in some individuals. Multidisciplinary monitoring across psychiatry, primary care, and psychological services is essential for long-term safety and relapse prevention.

Differentiating ADHD-related mood swings from bipolar episodes

ADHD mood shifts are typically short-lived and reactive, while bipolar mood episodes last days or weeks and involve significant changes in energy, sleep, and activity levels. Detailed clinical history, family risk factors, and symptom duration help clinicians distinguish between the two. Assessment by specialists experienced in both neurodevelopmental and mood disorders, such as through private or NHS referral pathways, is often necessary for an accurate diagnosis.

Key takeaway

Bipolar disorder is relatively common in people with ADHD, with studies suggesting comorbidity rates between 10 and 30 per cent. According to NICE and NHS guidance, safe management involves stabilising mood first, then introducing ADHD treatments alongside psychological support and regular review. With careful, coordinated care, both conditions can be effectively managed to improve long-term stability and quality of life.

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.