Have you ever wondered what causes SPD? If you or your child struggles with certain sounds, textures, lights, or smells, you’re not alone. Sensory Processing Disorder (SPD) can make everyday experiences feel confusing, overwhelming, or even painful. But where does it come from—and why does it affect some people more than others?
In this post, we’ll break down the known and possible causes of SPD in a way that’s easy to understand. While science is still working out the details, we’ll look at the key factors that researchers believe play a role.
What Causes Sensory Processing Disorder
Before we dive into the causes, it’s helpful to know what SPD actually is. Sensory processing disorder happens when the brain struggles to properly receive, interpret, or respond to sensory information. The exercise can involve any of the senses—touch, hearing, sight, smell, taste, movement, or body awareness.
Someone with SPD might be
- Hypersensitive (over-responsive): Loud noises feel painful, and certain fabrics cause distress.
- Hyposensitive (under-responsive): They may not notice when they are hurt or prefer intense movement such as spinning or jumping.
So, what is the underlying cause of sensory processing disorders? Let’s take a look.
Genetic Influences on SPD
Researchers believe genetics may play a role in the development of sensory processing disorders. In many families, SPD symptoms appear in more than one person, suggesting a hereditary link.
Some studies show that children with SPD often have a parent or sibling with similar traits, such as anxiety, ADHD, or sensory sensitivities. While no specific gene has been identified, the correlation is strong enough to be meaningful.
If SPD runs in your family, it doesn’t mean a child will definitely have it—but the chances could be higher.
Neurological Differences and Brain Function
One of the most well-supported ideas about what causes sensory processing disorder is that it relates to differences in brain function. Research using brain scans shows that individuals with SPD have unusual patterns of activity in areas responsible for:
- Processing sensory input
- Connecting sensory information between different brain regions
- Regulating emotional responses
These brain-based differences may explain why people with SPD react so strongly—or sometimes not at all—to certain sensory input.
In short, their brains may process information in a way that’s just… different. And, while this is not “wrong,” it can make typical environments extremely difficult.
Environmental Factors and Early Development
Beyond genetics and neurology, environmental factors play a role in the development of sensory processing disorders. Early life experiences matter a lot—especially those that shape how the brain grows and connects.
Some examples include
- Premature birth or low birth weight
- Early exposure to toxins or substances
- Complications during pregnancy or delivery
- Limited sensory input during infancy (e.g., time spent in a NICU)
Children who don’t receive consistent or healthy sensory stimulation during key stages of development may be more likely to develop sensory processing challenges later.
However, it’s important to remember that many children with SPD have no clear history of trauma or medical issues—so environment alone doesn’t explain everything.
SPD and Co-Occurring Conditions
Another factor when exploring what causes sensory processing disorder is its connection to other developmental conditions. SPD often appears alongside
- Autism Spectrum Disorder (ASD)
- Attention-Deficit/Hyperactivity Disorder (ADHD)
- Anxiety disorders
- Learning disabilities
While SPD can exist on its own, these overlapping diagnoses suggest there may be shared causes or brain mechanisms. That said, not every person with autism or ADHD has SPD, and not everyone with SPD is autistic.
Still, this connection helps doctors and therapists create more effective treatment plans based on individual needs.
Can Parenting or Lifestyle Affect SPD?
Many parents worry that something they did—or didn’t do—caused their child’s sensory challenges. But rest assured: parenting does not cause SPD. It’s not the result of poor discipline, too much screen time, or a lack of structure.
SPD is believed to come from a combination of genetic, neurological, and developmental factors. While environment can influence how symptoms show up, it’s not to blame for the root cause.
In fact, supportive parenting can have a significant positive impact on how children manage their sensory world.
Final Thoughts
So, what causes sensory processing disorder? While there isn’t one single answer, science points to a mix of genetic, brain-based, and early developmental factors. Each person’s experience is unique, and there’s still much to learn—but we’re getting closer.
Most importantly, knowing the causes can help us respond with understanding, patience, and support. Whether you’re a parent, teacher, or someone living with SPD, awareness is the first step toward making life easier and more inclusive.