Attention deficit hyperactivity disorder (ADHD) and bipolar disorder have similar symptoms. This is so much the case that they’re often misdiagnosed for one another. But this doesn’t mean that they don’t show up together.

Approximately 3 to 6 percent of the adult population has ADHD.

It’s also estimated that about 4.4 percent of American adults will experience bipolar disorder at some point in their life, according to the National Institute of Mental Health.

ADHD and bipolar disorder often occur together. Some symptoms, such as impulsivity and inattention, can overlap. This can sometimes make them difficult to tell apart.

It’s still not entirely clear why ADHD and bipolar disorder commonly occur together. It’s thought that genetic and biological factors could be partially responsible.

Keep reading as we take a look at what the latest research has uncovered about ADHD in people with bipolar disorder.

ADHD and bipolar disorder are common comorbidities. Comorbidities are two conditions that occur in the same person at the same time.

How common is bipolar disorder in people with ADHD?

In a 2018 study, researchers sought to examine the prevalence of bipolar disorder in a group of 2.4 million people born in Denmark between 1955 and 1991.

They looked at bipolar disorder in people diagnosed with ADHD, an anxiety disorder, both, or neither.

The researchers found that bipolar disorder was almost 11 times more likely in people with a prior diagnosis of ADHD, compared with people who had no prior diagnosis of ADHD or anxiety.

The incidence rate of bipolar disorder was 30 times higher in people with a prior diagnosis of ADHD and anxiety than people who weren’t diagnosed with either.

How common is ADHD in people with bipolar disorder?

A 2021 review of studies analyzed prevalence rates of bipolar disorder and ADHD in more than 646,000 participants.

The researchers found that about 1 in 13 adults with ADHD was also diagnosed with bipolar disorder, and 1 in 6 adults with bipolar disorder had ADHD.

Why do bipolar disorder and ADHD often occur together?

It’s still not entirely clear why bipolar disorder and ADHD often occur at the same time. One theory is that shared genetic and biological factors may be partially responsible for the association.

In a 2015 study, researchers examined data from 13,532 twins to try to understand the degree to which genetic factors play a role in the development of ADHD in people with bipolar disorder.

They found that genetic factors associated with mania were 25 to 42 percent associated with ADHD symptoms, suggesting that there’s some biological connection between the two conditions.

What’s the outlook for people with ADHD and bipolar disorder together?

People with both ADHD and bipolar disorder may experience more severe symptoms than people with either ADHD or bipolar disorder.

A 2015 study published in the Journal of Affective Disorders found that people with both conditions experienced a greater number of suicide attempts compared with people who only had bipolar disorder.

Multiple studies have also found that ADHD is associated with:

  • an earlier onset of bipolar disorder
  • a higher frequency of mood episodes
  • increased violence against others

When making the diagnosis of bipolar disorder in a person with ADHD, a clinician will follow guidelines laid out in the most recent edition of the American Psychiatric Association’s Diagnostic and Statistical Manual.

ADHD and bipolar disorder can share symptoms such as hyperactivity, distractibility, and reduced inhibition, which makes diagnosis difficult.

Bipolar disorder is generally episodic, meaning periods of mania and depression are often short-lived.

People with ADHD show relatively constant symptoms. A clinician can use this difference as a clue to which disorder you might be experiencing.

Some researchers consider a diagnosis of ADHD and bipolar disorder to be distinct from other forms of ADHD.

There’s a limited amount of research examining the best treatment option for people with ADHD and bipolar disorder. The treatment of ADHD and bipolar disorder together is currently based on a clinician’s observations rather than a standard set of guidelines.

According to a 2017 article published in the Journal of Psychiatry and Neuroscience, the best option might be to treat symptoms of bipolar disorder first.

Once bipolar symptoms are under control, then ADHD can be targeted with medication.

However, this recommendation is meant as a suggestion for clinicians, not as a definitive treatment strategy. More research is needed to evaluate what the best treatment is.

Bipolar disorder treatment typically includes a combination of medication and therapies. Medications for bipolar disorder include:

ADHD treatment often includes medications, the most common being central nervous system stimulants.

Some research suggests that stimulants used to treat ADHD may lead to manic and psychotic episodes in people with ADHD and bipolar disorder. But other researchers have found that people with ADHD and bipolar disorder respond well to these medications.

A large 2016 study found that the medication methylphenidate (Ritalin) may be a safe treatment option for people with ADHD and bipolar disorder who are on mood stabilizers to manage bipolar symptoms.

The study found that people not on mood stabilizers experienced a 6.7 times increase in manic episodes over a 3-month period.

ADHD and bipolar disorder have similar symptoms and are commonly misdiagnosed for one another.

People often experience both disorders together. People who have ADHD and bipolar disorder may have more severe symptoms than people who only have one.

More research is needed to understand the best treatment option for people who have ADHD and bipolar disorder. It’s been suggested that the best option may be to treat bipolar disorder first and then target ADHD symptoms.