The Connection Between Bipolar Disorder and Autism: What to Know

Bipolar disorder and autism spectrum disorder (ASD) share some traits and may share some genetic roots. In addition, autistic people are at increased risk for bipolar disorder and people with bipolar disorder are more likely to be autistic. The two conditions, however, are not the same.

While a connection between the two is not well understood, healthcare providers can explore traits and determine whether you have bipolar disorder, are autistic, or both. About 2.8% of the U.S. population is diagnosed with bipolar disorder. And about 1.85% of Americans have an autism spectrum diagnosis.

The Connection Between Bipolar Disorder and Autism

Bipolar disorder and ASD are distinct diagnoses. However, there are some ways in which the two conditions can look similar, and it is perfectly possible to be diagnosed as autistic and with bipolar disorder.

According to one study, about 7% of autistic people also have a bipolar diagnosis, nearly three times the percentage of people in the general population.

Another study found about 40% of people diagnosed with bipolar disorder also exhibit traits of autism spectrum disorder.

Recently, studies have found genetic connections between autism and several mental illnesses, including schizophrenia and bipolar disorder; this probably explains some of the symptom crossovers. These connections also expand on the stance that many neurodiversity experts hold that includes conditions such as schizophrenia, bipolar disorder, PTSD, OCD, etc as forms of neurodivergence.

In addition to the reality that there is real crossover, there are many symptoms of bipolar that appear in autistic people with higher support needs, but for entirely different reasons. These include hyperactivity, disturbed sleep, impulsivity, agitation, and irritability.

While it's reasonable to ascribe some of those traits to bipolar disorder, it can be challenging (especially with a non-verbal individual) to sort out bipolar from autistic traits.

Comparing Bipolar Disorder and Autism

Because autistic people and people with bipolar disorder can sometimes behave in similar ways, at times, it can be hard to tell the difference. Autism is a developmental disability and traits must appear before age 3. Bipolar disorder is a mental illness that may appear at any age and may be triggered by traumatic emotions.

Here's a look at the similarities and differences between the two disorders:

Causes

The causes of these disorders include:

• Genetics: Both autism and bipolar disorder have genetic links and can run in families. It is, however, possible for one twin to be autistic or have bipolar disorder while the other twin does not. Research suggests that some of the same genes may be implicated in autism and bipolar disorder (along with other forms of neurodivergence).
• Environmental issues: Episodes in bipolar disorder can be set off by a stressful event such as a death or divorce. This is not the case with autism.
• Brain structure and function: Some evidence suggests that the brains of autistic people and people with bipolar disorder are slightly different from neurotypical brains but in somewhat different ways.

Signs and Traits

Depending on the individual, traits of autism and bipolar disorder can look similar. For example, people with either condition can exhibit:

• Irritability 
• Disturbed sleep 
• Repetitive behavior 
• Distractibility and impulsivity  
• Loud, rapid, and virtually nonstop speech   
• Impulsivity that can lead to aggression

These behaviors, however, occur for very different reasons, and there are distinct traits that exist only in autism and only in bipolar disorder.

If you have concerns that you have bipolar disorder as an autistic person, or that your autistic child has bipolar disorder, you should contact a physician—but also bear in mind that:

• Autism is not a cyclical disorder. You should not see sudden and severe mood shifts occurring for no apparent reason.
• Autism can't be triggered by an event. Symptoms must appear before age 3, and while autistic traits can change, you will not see a point at which they "disappear." However, autistic burnout is triggered by chronic stress; it can cause a person to be unable to mask as well as they've done in the past, which can look like an increase in autistic traits.
• Autism, on its own, should not cause severe depression or suicidal thoughts. However, autistic people are more likely to be depressed than allistic people due to the systemic and interpersonal stressors that affect all disabled people.
• Autistic people are likely to have support needs with communication, sensory over- or under-sensitivity, and executive functioning. These are not necessarily symptoms of bipolar disorder.
• "Stimming" (rocking, pacing, mumbling, etc.) is common with autistic people and is a tool for self-calming. If it has been present consistently for a long time, it is probably unrelated to bipolar disorder.
  

Diagnosis

Autism is typically diagnosed in early childhood, though individuals prolific at masking or with lower support needs may be diagnosed as teens or adults. Autism is generally diagnosed through observations and, specific tests and questionnaires, as there is no biological marker for the disorder. Diagnosticians are looking for:

• Specific behavioral differences typical of autism (stimming, lack of eye contact, etc.)
• Speech delays or idiosyncrasies such as echolalia (repeating the same phrases or "echoing" TV or movies)
• Sensory dysfunction
• Social and communication support needs

Bipolar disorder is rarely diagnosed in toddlers. The diagnostic process often starts with a physical exam and laboratory tests to rule out other issues, such as thyroid problems, which can cause mood swings. The patient must have experienced at least one episode of mania.

Like autism, bipolar disorder has no biological marker, so physical tests can only rule out other issues.

Therapy and Treatment

Therapy for autism may or may not include pharmaceuticals. Typically, autism is approached with therapies such as applied behavior analysis, developmental and play therapies, speech therapy, and social skills training. When pharmaceuticals are used, they often include anti-anxiety medications and second-generation antipsychotics.

Treatment of bipolar disorder is more likely to include specific mood stabilizers such as lithium. Second-generation antipsychotics and antidepressants may also be used. In addition, cognitive therapy (talk therapy) is often helpful for people with bipolar disorder.

When to Seek Professional Treatment

If you believe or suspect that you or a loved one might be autistic or have bipolar disorder, your first step should be seeing a healthcare professional. Describe the relevant traits, and ask for evaluation.

Be sure that the person or team doing the evaluation has solid experience with both conditions, as it is easy to mistake one for the other or to miss signs of mental illness in an autistic person.

Adults seeking diagnosis and treatment should document symptoms carefully, with particular attention to these questions:

• How long have these traits been present? (If they appear suddenly, they may not be related to autism.)
• Have there been cycling episodes of mania and depression? When, how often, and for how long? (This may suggest bipolar disorder).
• Does the individual have suicidal thoughts? (While such thoughts occur in both disorders, they are more likely to appear in someone with bipolar disorder.)
• Does the individual have difficulties with social communication, symptoms of sensory dysfunction (problems with bright lights and loud noises, for example), or speech delays? (While some of these symptoms occur in both disorders, if all are present, they may suggest autism.)

Summary

Bipolar disorder and autism spectrum disorder are not the same. However, they have some common traits and may share some underlying genetic factors. Autistic people are at increased risk for bipolar disorder and bipolar people are more likely to be autistic.

Traits, age of onset, diagnostic criteria, and treatment methods are different for the two conditions. Any health concerns should be brought up with a healthcare provider to get a proper diagnosis. Adults should seek a professional diagnosis.