Why can bipolar disorder go undiagnosed for years?

Bipolar disorder does not follow one predictable pattern, so it can look different from person to person. Some experience severe episodes of mania, while others have subtler periods of hypomania that can be much harder to recognize.

There are two main types of bipolar disorder. Bipolar I is defined by at least one manic episode. During mania, someone may feel unusually euphoric or irritable, have far more energy than usual or need very little sleep without feeling tired. They may also have racing thoughts, speak much faster than usual or act impulsively.

That impulsivity can lead to risky behavior, such as excessive spending, substance misuse or reckless driving. In severe cases, mania can include psychosis, such as hallucinations or delusions. People with bipolar I often experience depression as well, although a depressive episode is not required for diagnosis.

Bipolar II involves at least one major depressive episode and at least one hypomanic episode, with no history of mania. Hypomania is less severe than mania and typically causes less disruption to daily life. But bipolar II is not simply a milder form of the disorder; its depressive episodes can be severe and long-lasting.

During hypomania, someone may feel more confident, energetic, productive, creative or social than usual. Because those changes can feel positive, the person—and those around them—may not see them as signs of a mental health condition.

“That is one reason bipolar II can be especially difficult to identify,” says Dr. Goldberger. “Patients may feel as though they are functioning at their best.”

For many people with bipolar disorder, depression is what first brings them into care. An estimated 50% to 80% experience their first recognized episode as major depression rather than mania or hypomania.

That can make the condition difficult to identify. The depressive symptoms can look like MDD, while periods of mania or hypomania may not have happened yet, may have gone unrecognized or may not come up during an appointment. In some cases, five to eight years pass between a person’s first depressive episode and the first recognized manic or hypomanic episode.

It’s not surprising, then, that research suggests about 4 in 10 or more people eventually diagnosed with bipolar disorder first receive a diagnosis of MDD. But the distinction is important because the two conditions are treated differently.

“When a patient seeks care for depression, the clinician may not yet know about earlier or emerging periods of mania or hypomania,” says Dr. Goldberger. “Without that history, it can be difficult to recognize the underlying bipolar disorder.”

That’s why a diagnosis depends on more than the symptoms someone is experiencing at one moment. Looking at how their mood, sleep, energy and behavior have changed over time can help reveal patterns that point to bipolar disorder and guide them toward the right care.

Bipolar disorder isn’t always characterized by clearly separate episodes of depression and mania or hypomania. Some people experience “mixed features,” in which depressive symptoms occur alongside symptoms associated with mania or hypomania.

For instance, a person may feel deeply depressed or hopeless while also experiencing racing thoughts, unusually high energy, irritability or an inability to sleep. These symptoms can pull in different directions, creating a particularly complex clinical picture, explains Dr. Goldberger.

“Mixed features can be challenging because clinicians must look at the combination of symptoms rather than focusing only on the most visible one,” says Dr. Goldberger. “Finding the right treatment approach requires careful assessment and can take time.”

That complexity underscores why researchers continue to study treatment approaches across the full spectrum of bipolar disorder. Johnson & Johnson’s psychiatry portfolio includes an approved treatment for depressive episodes associated with bipolar I or II disorder in adults. The company is also evaluating whether the treatment could also help address manic episodes associated with bipolar I disorder.

For someone who has spent years believing they have MDD, receiving a bipolar disorder diagnosis can bring a new understanding of past experiences—and new questions about the future. Periods once viewed as unusually productive, confident or energetic may take on a different meaning.

The adjustment can be particularly complex for people with bipolar II because hypomanic periods may not have felt concerning. They may instead have felt like welcome relief from depression.

“It can take time for someone to recognize that changes they experienced as positive may have been part of a larger pattern,” says Dr. Goldberger. “Understanding that pattern is an important part of learning to manage the condition.”

Beginning treatment can also require adjustment. People may have concerns about how treatment will affect their energy, creativity, identity or ability to function. Open conversations with HCPs about symptoms, treatment expectations and daily life are an important part of ongoing care.

Supporting someone with bipolar disorder therefore means more than explaining a diagnosis. It also means helping them understand their individual symptom patterns and working with their care team on a treatment plan that supports long-term health and day-to-day functioning.

There is no laboratory test, imaging scan or biomarker that can definitively diagnose bipolar disorder. Instead, diagnosis depends on building a detailed clinical history that examines changes in mood, energy, sleep, behavior and daily functioning over time.

“Diagnosing bipolar disorder requires asking the right questions and understanding when a person’s behavior falls outside their usual patterns,” says Dr. Goldberger.

An HCP might ask whether there have been periods when someone needed very little sleep but still felt unusually energetic, experienced a flood of ideas, spoke more quickly than usual or took on an unusual number of ambitious projects.

They may also ask about periods of impulsive or uncharacteristic behavior, such as excessive spending or making major decisions without fully considering the consequences. Input from family members or others close to the patient may help identify changes the person didn’t recognize at the time.

Greater awareness of mania and hypomania may help make these patterns easier to recognize. Addressing stigma is equally important because fear or misunderstanding can keep people from discussing symptoms or seeking care.

Recognizing bipolar disorder means looking beyond a single episode and beyond assumptions about what depression or mania should look like. A fuller understanding of symptoms over time can support a more informed diagnosis and more appropriate care.

While bipolar disorder requires ongoing management, effective treatment can help people manage symptoms and improve their quality of life.