ADHD or bipolar disorder?

Chronic symptoms versus distinct episodes is the core distinction

ADHD symptoms, under DSM-5-TR criteria, must be present before age 12 and persist continuously across settings, without the person cycling in and out of periods of dramatically different functioning. Bipolar disorder is defined by discrete mood episodes, at least one week of elevated or irritable mood with increased energy for mania, or at least four days for hypomania, plus separate depressive episodes, each marking a clear shift from that person's usual baseline.

Put simply, someone with ADHD tends to describe their attention and impulsivity as roughly the same, for better or worse, most weeks of most years. Someone with bipolar disorder describes clearly different chapters, weeks of feeling unusually high-energy and less in need of sleep, followed by separate periods of low mood and reduced functioning, with more typical functioning in between.

Some features genuinely overlap between the two conditions

Impulsivity, distractibility, and rapid, pressured speech can appear in both ADHD and a manic or hypomanic episode, which is exactly why the two are sometimes confused, especially without a full history. The distinguishing factor is timing and pattern: ADHD's version of these features is present continuously, while bipolar disorder's version appears specifically during an episode and improves or disappears between episodes.

A thorough assessment specifically screens for bipolar history

Because stimulant medications carry a recognized risk of triggering or worsening a manic or hypomanic episode in someone with bipolar disorder, the Canadian ADHD Practice Guidelines call for screening personal and family history for bipolar disorder before starting stimulant treatment, not just diagnosing ADHD in isolation.

This screening is asked of everyone being assessed for ADHD, not only people who mention mood concerns upfront, since a history of past episodes isn't always something someone thinks to bring up on their own, especially if it happened years earlier or wasn't recognized as significant at the time.

Both conditions can occur together, which requires careful sequencing

It's possible to have both ADHD and bipolar disorder. When that's the case, guidelines generally call for stabilizing mood first, working with a psychiatrist managing the bipolar disorder, before starting or adjusting ADHD medication, since treating ADHD symptoms in the middle of an unstable mood episode can complicate both.

Once mood is stable, ADHD symptoms that persist independently of any mood episode can be addressed on their own timeline, coordinated between the psychiatrist and the clinician managing ADHD care rather than one prescriber working without input from the other.

Getting an accurate picture matters for safety, not just labelling

If you notice a family history of bipolar disorder or have experienced distinct periods of unusually elevated mood, energy, or reduced need for sleep, mentioning this clearly during an assessment is important, since it changes the treatment approach. A related question some people ask is whether stimulants can specifically trigger mania. If you're in crisis or thinking about harming yourself, call or text 9-8-8, Canada's Suicide Crisis Helpline, or call 911, and ConnexOntario offers free, confidential help finding mental health services in Ontario.

Being asked about mood history during an ADHD assessment isn't a sign anything is assumed to be wrong; it's a standard safety question built into a proper intake process, asked of everyone regardless of how likely bipolar disorder seems, precisely because it can be easy to miss otherwise. Answering honestly, even if it feels unrelated, helps your clinician build an accurate picture from the start.