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Bipolar age of onset can vary. If you or someone you know is experiencing signs of this condition later in life, the reason might be late onset bipolar.

The word bipolar means two poles, or extremes. It’s a fitting name for this condition that features drastic shifts in mood and energy.

People living with bipolar disorder experience episodes of mania and depression. During a manic episode, you might be awake all night brimming with energy and ideas, and function on little sleep for several days. This may sound like an advantage.

However, mania transitions into a depression that can leave you feeling empty, pessimistic, and sad. You may not have the energy to get out of bed, let alone make it through the day.

Although bipolar often appears in adolescence and early 20s, some people experience their first symptoms later in life.

The average age of bipolar onset is around 25 years old, although it can vary.

Sometimes bipolar symptoms start in childhood or later in life. However, the most frequent range of onset is between the ages of 14 to 21 years.

Childhood bipolar is relatively rare, with only up to 3% of children receiving this diagnosis.

According to the National Institute of Mental Health (NIMH), about 4.4% of adults (18 years of age or older) in the United States will experience bipolar disorder at some point in their lives. It affects men and women equally.

NIMH estimates that nearly 2.9% of adolescents — those who are between 13 and 18 years old — will experience bipolar disorder at some point, with the highest prevalence (up to 4.3%) seen in 17- to 18-year-olds.

Despite common belief, bipolar disorder doesn’t just occur in young people. In recent years, research has shown an increase in the diagnosis of late onset bipolar disorder (LOBD).

According to a 2015 report from the International Society for Bipolar Disorders Task Force on Older-Age Bipolar Disorder (OABD), up to 25% of people with bipolar disorder are 60 years of age and older. It’s estimated that between 5% and 10% of people start showing symptoms of bipolar disorder after the age of 50 years old.

People diagnosed with LOBD differ from those with early onset BD in several ways.

  • They have more association with neurological disorders like cerebrovascular disease — such as stroke or aneurysms.
  • They have fewer occurrences of mood disorders in their family history.
  • They have more comorbid medical conditions but fewer comorbid psychiatric diagnoses.
  • They may experience depressive episodes more often than mania or hypomania. These episodes can also be more frequent and severe than those seen in younger people with bipolar disorder.

In addition, people with LOBD have vascular changes in their right brain hemispheres that have been linked to manic episodes, and vascular lesions in their left cerebral hemispheres that have been associated with depressive episodes. However, more research is needed to support these claims.

Research suggests several factors that can contribute to the development of bipolar disorder.

  • Genetics: Family history is more often linked to early onset bipolar than LOBD. Having a parent or sibling with bipolar disorder may increase your chances of developing the condition, but it’s no guarantee. Some people with family history never develop bipolar.
  • Stress: An event or ongoing situation can trigger manic and depressive episodes. Examples include a death in the family, financial hardship, or a difficult relationship.
  • Brain structure: People with bipolar disorder may have structural differences in their brains. LOBD features vascular differences in both the left and right hemispheres of the brain.

Medical conditions can sometimes cause late-onset bipolar symptoms. Examples include:

  • vascular dementia
  • encephalitis
  • neurosyphilis
  • stroke
  • HIV encephalopathy
  • multiple sclerosis
  • traumatic brain injury (TBI)
  • Huntington’s disease
  • brain tumors
  • lupus
  • hyperthyroidism
  • vitamin B12 deficiency

Late-onset bipolar disorder is a diagnosis of exclusion, meaning that a healthcare professional will rule out other conditions that may be causing your symptoms, like cerebrovascular disease.

They will likely begin with a thorough medical and family history and conduct medical assessments like lab and imaging tests.

Symptoms that may be assessed when diagnosing LOBD can include:

  • mania, with fewer and milder episodes than in early onset bipolar disorder
  • depressive episodes
  • irritability
  • psychomotor changes (rapid or slowed speech, physical agitation)
  • mental flexibility impairments
  • cognitive impairments, more pronounced than in early onset bipolar disorder

Once potential medical causes for symptoms have been ruled out, you may be referred to a mental health professional for further evaluation and testing.

It helps to get an early diagnosis so that you can start treatment sooner. According to the National Alliance on Mental Illness (NAMI), delaying treatment can allow bipolar disorder to progress and worsen.

Much like in the case of early onset bipolar disorder, medications may be prescribed to help treat your symptoms.

These medications include:

Some evidence suggests that people who take lithium for bipolar disorder later in life might experience lower rates of dementia or Alzheimer’s disease. More research is needed to determine if lithium can treat the cognitive decline from bipolar disorder.

There are lithium side effects to consider, which could include:

  • tremors
  • cognitive impairment
  • renal dysfunction
  • rash
  • weight gain
  • hypothyroidism

Potential medication interactions and other side effects might also be considered. People with LOBD are more likely than younger people with bipolar disorder to be taking medications for other conditions. Also, some antipsychotic medications can cause serious side effects in people living with dementia.

Those who don’t respond to medication can try electroconvulsive therapy (ECT), which sometimes works for LOBD. Transcranial magnetic stimulation is another neurostimulation technique that may be beneficial, although more research is needed for this age group.

Psychotherapy can help younger people with bipolar disorder, but more research is needed to determine if treatments like cognitive behavioral therapy (CBT) and interpersonal therapy (IPT) can help treat LOBD.

Bipolar is a serious condition, but it’s treatable.

An accurate diagnosis and prompt treatment can help reduce manic and depressive episodes. This helps manage your symptoms and reduces the chance that your symptoms get worse.

Sometimes treatable medical conditions can cause bipolar symptoms when you’re older. A complete medical history can help a healthcare professional identify such conditions. They can also help you minimize the chance of interactions between bipolar medications and other medications you may be taking.

It may feel overwhelming to be diagnosed with bipolar disorder when you’re older, but there is support available. Here are some resources you can try: