The signs of bipolar disorder and autism can look similar, so how do you know which one you’re experiencing?

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Bipolar disorder involves an array of symptoms that occur through episodes of high and low mood. You may transition from periods of agitation to times where you feel hopeless and can’t concentrate.

Some behaviors associated with autism spectrum disorder — like irritability, slow social responsiveness, or excited talking — can appear similar to what happens during mood episodes of bipolar disorder.

It’s not always easy to know which condition is at hand. It could be bipolar disorder, autism — or both.

No evidence indicates bipolar disorder causes autism or autism causes bipolar disorder.

Research from 2018 does suggest these two conditions may share genetic expression patterns, and a 2016 study found genetic variants that can increase the chances of developing one or the other.

Genetics may account for an overlap of symptoms and may also help explain why you may be more likely to experience bipolar disorder if you’ve already been diagnosed with autism.

Autism and bipolar disorder prevalence

In a 2018 study on Asperger’s syndrome, a condition now included under the scope of autism spectrum disorders (ASDs), researchers found as many as 27% of autistic children showed symptoms of bipolar disorder.

A small-scale study from 2019 suggested autistic people were 9.34 times more likely than neurotypical people to receive a clinical diagnosis of bipolar disorder.

More recent studies continue to support this correlation but indicate the actual number of dual diagnoses may be either higher or lower.

In 2013, a large, family-based study found as many as 30% of people living with bipolar disorder also met the criteria for an ASD diagnosis. The average onset of bipolar disorder was also noted as significantly earlier when co-occurring with ASD.

A 2016 study, however, found the co-occurrence rate was closer to 8%, also noting the onset of bipolar disorder was earlier among autistic people.

That same study found co-occurring ASD and bipolar disorder more frequently included symptoms of:

  • racing thoughts
  • distractibility
  • depressed mood
  • social withdrawal
  • low reactivity of mood states

Bipolar disorder is a mental health disorder characterized by extreme mood, activity, and energy level shifts.

It involves periods of elevated, agitated mood known as mania, and periods of low mood identified as depressive episodes.

The three primary forms of bipolar disorder include:

  • Bipolar I disorder. Experiencing at least one episode of mania, but most commonly episodes of both mania and depression.
  • Bipolar II disorder. Depressive episodes mixed with mild forms of elevated mood called “hypomania.”
  • Cyclothymia. Hypomania and depressive episodes frequently cycling for a period of at least 2 years.

The exact cause of bipolar disorder is unknown. Genetics, internal stress coping mechanisms, and alterations in brain structure are all thought to play a role.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with symptoms primarily seen within the first 2 years of life.

It’s a complex condition that can vary significantly in level of impairment.

According to the Diagnostic and Statistical Manual of Mental Disorders, fifth Edition (DSM-5), the core criteria for an ASD diagnosis are:

  • persistent deficits in social communication and interaction
  • repetitive and restrictive patterns of behavior
  • symptoms are present in early childhood and cause clinically significant impairment

A broad range of symptoms can meet the criteria of ASD, including:

  • repetitive habits or behaviors, like repeating phrases
  • hyper-focusing on a specific topic
  • inconsistent eye movement or contact
  • slow response to verbal cues
  • being nonspeaking or unable to hold conversation
  • delayed facial expressions
  • sensitivity to sensory input
  • not adjusting to changes in routine

The exact cause of ASD is unknown, though genetics are thought to be an important factor. You may also have an increased chance of experiencing ASD if you:

Symptoms of bipolar disorder and autism aren’t always straightforward, especially when they occur simultaneously.


Some of the similarities between bipolar disorder and autism include:

  • Both ASD and bipolar disorder can feature similar mood-related symptoms such as:
    • agitation
    • rapid speech
    • difficulty concentrating
    • irritability
    • poor judgment
  • Sleep disturbance is common with both conditions.
  • Genetics may play a role in both ASD and bipolar disorder.
  • Social challenges, such as withdrawal or difficulty maintaining relationships, may be experienced.
  • Both are lifelong conditions.


Here are some differences between autism and bipolar disorder:

  • ASD is often identified within the first 2 years of life, whereas bipolar disorder tends to be diagnosed around age 25.
  • ASD is a neurodevelopmental disorder, which means growth, learning, and brain development are affected from an early age. Bipolar disorder is a mental disorder and is not associated with early developmental and learning impairment.
  • Bipolar disorder symptoms stem from cycling mood episodes. ASD symptoms may have mood traits, but they are often consistent, repetitive, and related to behavior and learning.
  • Symptoms of bipolar disorder can be improved with medications to the point where your daily life is minimally affected. Often, therapy for autistic people is focused on life skills and doesn’t involve medication.

Both ASD and bipolar disorder can be diagnosed by a mental health professional based on your symptoms.


ASD diagnosis may first come from your pediatric medical team as they compare your development path and behavior patterns against medical benchmarks.

As a child, your language skills, cognitive abilities, and neurological responses may all be evaluated. Your pediatric team will also look to identify common behaviors known as the hallmarks of ASD in children.

Bipolar disorder

Bipolar disorder tends to occur later in life compared with ASD, around early adulthood.

Since there are no lab tests that can definitively identify bipolar disorder, a mental health professional will determine a diagnosis based on your symptoms and their frequency, and how they’re impacting your life.

You may also be sent for a medical screening to rule out the possibility of underlying physical conditions that could be responsible for changes in mood.

Bipolar disorder is often treated through the use of medications, such as mood stabilizers, and through varying forms of psychotherapy.

Cognitive behavioral therapy (CBT) may be used to help identify and restructure unhelpful behaviors and thought patterns.

It is possible to improve your symptoms and lead a functional life with bipolar disorder.

The autism discussion

Many people don’t view ASD as a condition that requires treatment.

Popular belief asserts autistic people may act and perceive things uniquely, but that doesn’t mean they’re any less capable.

The autism spectrum is broad. It’s entirely possible for autistic people not to need professional guidance.

For some people, however, ASD can present significant challenges in daily life. In these cases, ASD therapies exist to help improve social interactions, communication skills, and physical mobility.

Comorbid ASD and bipolar disorder

Autistic people who have also been diagnosed with bipolar disorder may be placed on medications to stabilize mood initially while the behavioral aspects of both conditions can be managed through psychotherapy approaches.

Autism and bipolar disorder are two separate diagnoses, but you can experience both at the same time.

Genetic overlaps between these conditions may account for some similar symptoms, but there are a number of differences that set ASD and bipolar disorder apart.

Speaking with a mental health professional can help identify which condition — or conditions — may be causing symptoms and what treatment options are best for you.