ADHD vs. Bipolar: How to Tell the Difference and Why It Matters

The human mind is both wonderfully complex and sometimes a little messy in the way it expresses distress or difference. It’s no wonder that certain mental health conditions can look remarkably similar from the outside – even to trained eyes. ADHD and bipolar disorder are two such conditions. They can share overlapping symptoms that make it tricky to know which is which, and in some cases, whether both might be present at the same time.

Understanding the differences matters. Not because one diagnosis is more serious or more ‘real’ than the other – both are valid ways the brain and mind can work – but because the way we support, treat, and adapt life for someone with ADHD is very different from how we help someone with bipolar disorder. If we get the diagnosis wrong, the person’s care can be less effective, sometimes even harmful.

ADHD, or attention-deficit/hyperactivity disorder, is a neurodevelopmental condition that starts in childhood and continues across the lifespan. It affects attention, impulse control, self-regulation, and often comes with a kaleidoscope of related challenges like emotional intensity, time blindness, and difficulty switching tasks. Bipolar disorder, on the other hand, is a mood disorder that usually emerges in adolescence or early adulthood and involves distinct episodes of elevated mood (mania or hypomania) and depression. It’s about patterns of mood over time, rather than a persistent style of thinking and acting from birth.

And here’s where things get tangled: both conditions can involve restlessness, impulsivity, distractibility, rapid speech, racing thoughts, risk-taking, and emotional ups and downs. It’s not unusual for a person to come to therapy or a GP saying, “I think I might have bipolar disorder” when they actually have ADHD, or the other way around. Some people even have both – research suggests rates of comorbidity are higher than we once thought, with studies finding anywhere between 9% and 21% of adults with ADHD also meeting criteria for bipolar disorder at some point (Skirrow et al., 2012; Nierenberg et al., 2005).

So how do we tell them apart? This is where curiosity is key – curiosity about time, patterns, and triggers.

In ADHD, symptoms are relatively consistent over time. A person may be distractible and impulsive in January, June, and December – regardless of mood. While stress, environment, and interest can affect how strongly symptoms show up, they don’t tend to occur in distinct cycles. The inattention and impulsivity are part of how the brain processes information every day.

In bipolar disorder, changes are episodic. Mania or hypomania – periods of elevated or irritable mood, reduced need for sleep, grandiosity, and increased goal-directed activity – occur in bursts that can last days to weeks. Depression episodes follow or precede them, bringing low mood, hopelessness, fatigue, and slowed thinking. In between episodes, a person may feel and function quite ‘normally’ for months. These cycles are the cornerstone of the diagnosis.

There are also subtle but important distinctions in how similar symptoms are experienced. For example:

1. **Racing thoughts** in ADHD often feel like a jumble of competing ideas, distractions, and tangents – the brain flipping through channels too fast to focus. In mania, racing thoughts may feel more like a powerful, coherent flow of ideas that seem brilliant or urgent, with a drive to act on them.

2. **Sleep** is another clue. People with ADHD might stay up late because they’re hyperfocused on a project, lost in social media, or struggling with restlessness – but they still feel tired the next day. In mania or hypomania, sleep need genuinely drops, sometimes to just a few hours, without feeling fatigued.

3. **Mood shifts** in ADHD are typically short-lived and reactive to external events. A frustrating phone call can trigger anger that passes in an hour. In bipolar disorder, mood changes during episodes are more sustained and less tied to external triggers.

4. **Risk-taking and impulsivity** are common in both, but in ADHD it’s usually a constant personality feature, while in mania it tends to spike dramatically during elevated mood periods.

Getting this right is not just about naming a condition accurately. The treatments are very different. ADHD is often treated with stimulant medication, which can be life-changing – but in someone with undiagnosed bipolar disorder, stimulants can trigger or worsen manic episodes. Bipolar disorder is typically managed with mood stabilisers or atypical antipsychotics, medications that don’t target ADHD symptoms and can even dampen energy and focus. Misdiagnosis can delay the right help for years, sometimes decades.

Beyond medication, the therapeutic approaches also differ. ADHD therapy might focus on executive functioning skills, environmental scaffolding, and strategies for emotional regulation. Bipolar therapy includes mood monitoring, relapse prevention, and lifestyle stabilisation – sleep hygiene, stress management, and recognising early warning signs of mood episodes. In someone with both conditions, therapy needs to carefully integrate these approaches.

In clinical practice, teasing apart the two requires a thorough history that includes early childhood behaviour, school reports if available, family accounts, and a careful mapping of mood over time. Screening tools can help but are never enough on their own. We also need to be aware of the role of trauma, substance use, and other mental health conditions that can cloud the picture.

Importantly, it’s not about choosing one label and sticking to it forever. Our understanding of a person can evolve. Sometimes what first looks like ADHD turns out to be bipolar disorder once a manic episode appears years later. Sometimes an initial bipolar diagnosis gets revised when lifelong attentional and self-regulation differences become clearer. The best clinicians stay open to updating their understanding, and the best therapeutic relationships make space for this ongoing exploration.

For the person seeking answers, the experience of uncertainty can be frustrating and even frightening. But taking the time to get the diagnosis right is an act of care. It means you get treatment that fits the way your brain works, not the way we’ve mistaken it for working. It means the chance to build a life around the real challenges you face, with strategies and support that actually help.

If you or someone you care about recognises themselves in both ADHD and bipolar symptoms, the safest path is to seek a comprehensive assessment from a psychiatrist or psychologist experienced in both conditions. This usually involves several sessions, not just a quick checklist. Bring notes about your mood and energy patterns, and invite someone who knows you well to share their observations. This shared detective work is invaluable.

Therapy can help in more ways than just clarifying a diagnosis. A skilled psychologist can help you manage day-to-day functioning while the diagnostic picture unfolds, offer strategies for emotional regulation, support you through any distress that uncertainty brings, and help you advocate for the right medical care. Whether the final picture is ADHD, bipolar disorder, or both, therapy is a space to develop insight, self-compassion, and tools that work in your real life.

If you are curious about your own patterns and how they fit into the bigger picture, you can book an appointment with a psychologist to start this process. It’s never too late to get clarity, and understanding your brain is one of the most empowering journeys you can take.