Autism and Epilepsy

Autism and epilepsy occur together more often than expected by chance. Their overlap is especially important in people with intellectual disability, developmental and epileptic encephalopathies and certain genetic or chromosomal conditions.

Neither condition simply causes the other

The relationship is complex.

In many people, epilepsy and autistic features arise from shared neurodevelopmental biology rather than one condition directly producing the other.

Shared genetic causes

Many genes and genomic disorders can produce both epilepsy and autistic neurodevelopmental features.

Examples include conditions involving SCN2A, STXBP1, CDKL5, DEPDC5/GATOR1, tuberous sclerosis complex and numerous developmental and epileptic encephalopathies.

Not every autistic person has epilepsy

Epilepsy is an important comorbidity in autism, but it affects only a subset of autistic people.

Risk is higher in people with intellectual disability, more severe developmental impairment and some identifiable genetic syndromes.

Not every person with epilepsy and autism has a single-gene disorder

Genetics can be highly informative, but the overlap is heterogeneous.

Some people have chromosomal, single-gene or metabolic diagnoses while others do not receive a defined molecular cause.

Seizure recognition can be difficult

Repetitive movements, stereotypies, staring, sensory responses and behavioural shutdown can resemble seizures.

Conversely, subtle focal or absence seizures can be mistaken for autistic behaviour.

Video can help

Home video of concerning events can help clinicians determine whether episodes are stereotyped and whether formal video-EEG assessment is needed.

EEG abnormalities without seizures

Autistic people may have epileptiform EEG abnormalities without clinical epilepsy.

An abnormal EEG alone does not automatically mean that every behavioural event is a seizure or that antiseizure treatment is required.

Developmental regression

Regression requires careful assessment because many causes are possible.

In a person with epilepsy, clinicians may consider uncontrolled seizures, developmental and epileptic encephalopathy, sleep-activated epileptiform activity, medication effects, genetic disease and non-epileptic developmental causes.

Developmental and epileptic encephalopathies

In DEEs, developmental impairment can result both from the underlying biological disorder and from epileptic activity.

This is different from assuming that seizures alone caused autism.

Treatment of epilepsy

Antiseizure treatment is chosen according to seizure type, epilepsy syndrome, genetic diagnosis and the individual’s wider health.

There is no universal “autism-specific” antiseizure medicine.

Behavioural and sensory effects of medication

Some antiseizure medicines can affect alertness, irritability, sleep or behaviour.

People with communication difficulties may show adverse effects through behavioural change rather than being able to describe dizziness, fatigue or cognitive slowing.

Precision medicine

For a minority of genetic conditions, the molecular diagnosis changes epilepsy treatment or identifies targeted therapies.

For many others, precision medicine remains an area of active research rather than established routine treatment.

Communication during healthcare

Epilepsy appointments should adapt to sensory, communication and cognitive needs.

Visual explanations, additional processing time, familiar supporters and clear seizure descriptions can improve assessment without assuming the supporter should speak instead of the person.

Sleep

Sleep problems are common in autism and can also influence seizure control.

Assessment should consider sleep disorders, medication effects and nocturnal seizures rather than attributing all disrupted sleep to autism.

Genetic testing

Genetic evaluation is particularly relevant when autism occurs with epilepsy, intellectual disability, developmental regression, dysmorphic features, congenital anomalies or a strong family history.

The appropriate test may include exome/genome sequencing, copy-number analysis or syndrome-specific testing.

The central point

Autism and epilepsy frequently share underlying neurodevelopmental and genetic mechanisms. Behavioural differences should not automatically be labelled seizures, and seizures should not automatically be dismissed as autistic behaviour.

Sources

Medical note: new episodes of altered awareness, regression or unusual movements deserve individual clinical assessment rather than assumptions based on an autism diagnosis.

Evidence checked: September 2026.