Autism and Co-Occurring Conditions: What You Might Not Know

When people think about autism, they often picture a single, clearly defined condition. In reality, autism rarely exists in isolation. Many autistic individuals experience co-occurring conditions (also called comorbidities)—additional physical or mental health differences that can shape how autism presents in everyday life.

Understanding these can be incredibly helpful—not just for professionals, but for families, educators, and autistic people themselves. It helps explain why things feel harder than expected, and more importantly, it opens the door to the right support.

What Are Comorbidities?

A comorbidity simply means one or more additional conditions occurring alongside a primary diagnosis. In autism, these are very common.

Research suggests that the majority of autistic individuals have at least one co-occurring condition, and many have several. These aren’t “extra” problems—they are often deeply intertwined with how a person experiences the world.

The More Well-Known Comorbidities

1. ADHD (Attention-Deficit/Hyperactivity Disorder)

One of the most recognised overlaps is between autism and ADHD.

Many individuals experience:

• Difficulty focusing or sustaining attention

• Impulsivity

• Hyperactivity or restlessness

For some, this can look like a constant push-pull between needing routine (autism) and craving novelty (ADHD). This combination is sometimes informally referred to as “AuDHD.”

2. Anxiety Disorders

Anxiety is extremely common in autistic individuals, often due to:

• Sensory overload

• Social uncertainty

• Difficulty predicting or controlling environments

This may present as:

• Generalised anxiety

• Social anxiety

• Panic attacks

Importantly, anxiety in autism is often situational and cumulative, building up over time rather than appearing suddenly.

3. Depression

Living in a world that doesn’t always accommodate neurodivergent needs can take its toll. Depression may develop due to:

• Chronic stress

• Social isolation

• Masking (hiding autistic traits to fit in)

Depression can sometimes go unnoticed, particularly in individuals who already struggle to express emotions.

4. Learning Disabilities

Some autistic individuals also have a learning disability (intellectual disability), which can affect:

• Communication

• Daily living skills

• Academic learning

Others may have average or above-average intelligence but still experience specific learning differences, such as dyslexia.

Lesser Known—but Very Important—Comorbidities

This is where awareness often drops off—but these conditions can have a huge impact on quality of life.

5. Sensory Processing Differences

While sensory sensitivities are part of autism, some individuals experience more pronounced difficulties often linked to Sensory Processing Disorder.

This can include:

• Extreme sensitivity to sound, light, or textures

• Difficulty filtering background noise

• Overwhelm in busy environments

These experiences are not behavioural—they are neurological.

6. Sleep Disorders

Sleep issues are incredibly common, including:

• Difficulty falling asleep

• Frequent waking

• Irregular sleep patterns

Some research links this to differences in melatonin production, which regulates the sleep-wake cycle.

7. Gastrointestinal (Gut) Issues

Many autistic individuals experience digestive problems such as:

• Constipation

• Diarrhoea

• Abdominal pain

Conditions like Irritable Bowel Syndrome are reported more frequently in autistic populations.

The connection isn’t fully understood, but may involve the gut–brain axis, sensory sensitivities to food, or differences in diet.

8. Dyspraxia (Developmental Coordination Disorder)

Dyspraxia affects movement and coordination.

This can show up as:

• Clumsiness

• Difficulty with fine motor skills (e.g. handwriting)

• Challenges with planning physical actions

It’s often mistaken for carelessness, when it’s actually neurological.

9. Epilepsy

There is a higher prevalence of Epilepsy among autistic individuals compared to the general population.

Seizures can vary widely in severity and type, and may develop in childhood or later.

10. Eating Disorders

Autism is increasingly recognised as a factor in certain eating disorders, particularly Anorexia Nervosa.

This may be linked to:

• Sensory sensitivities to food

• Need for control or routine

• Anxiety

It’s important to recognise that eating difficulties in autism are not always about body image—they can have very different underlying causes.

11. Obsessive-Compulsive Disorder (OCD)

While autism can involve repetitive behaviours, Obsessive-Compulsive Disorder is different.

OCD involves:

• Intrusive, distressing thoughts (obsessions)

• Compulsive behaviours performed to reduce anxiety

Distinguishing between autism traits and OCD is important for proper support.

12. Hypermobile Ehlers-Danlos Syndrome (hEDS)

A lesser-known but increasingly discussed link is with Hypermobile Ehlers-Danlos Syndrome.

This connective tissue condition can cause:

• Joint hypermobility

• Chronic pain

• Fatigue

Some researchers are exploring a possible biological connection between autism and connective tissue differences.

13. Postural Orthostatic Tachycardia Syndrome (POTS)

Another under-recognised condition is Postural Orthostatic Tachycardia Syndrome, which affects the autonomic nervous system.

Symptoms include:

• Dizziness when standing

• Rapid heart rate

• Fatigue and brain fog

This can significantly impact daily functioning but is often overlooked.

Why This Matters

Understanding comorbidities changes everything.

It can:

• Explain behaviours that might otherwise be misunderstood

• Prevent misdiagnosis or missed diagnoses

• Lead to more effective, compassionate support

For example, what looks like “challenging behaviour” might actually be:

• Anxiety

• Pain

• Sensory overload

• Sleep deprivation

A More Holistic View of Autism

Autism is not just a “social communication condition.” It is a whole-body, whole-person experience that often overlaps with many other aspects of health.

Recognising this helps shift the focus from:

“What’s wrong?”

to:

“What support does this person need to thrive?”

Final Thoughts

If you or someone you support is autistic and struggling, it’s worth considering whether a co-occurring condition might be part of the picture.

Because when we understand the full picture, we can:

• Support more effectively

• Reduce distress

• Improve quality of life

And ultimately, that’s what truly matters.