Causes & Effects of Sensory Processing Disorder

Learn about sensory processing disorder

Sensory processing disorder (SPD), once known as sensory integration dysfunction, refers to a condition in the brain in which cells experience difficulty receiving and responding to information that is obtained through the senses. The way in which the nervous system receives sensory messages and then turns those messages into appropriate corresponding actions and behaviors is referred to as sensory processing. When an individual’s nervous system is not able to appropriately turn sensory messages into correlating actions or behaviors, he or she is likely to be suffering from SPD. While everyone can experience occasional difficulties with appropriately processing information received by the senses, for people with sensory processing integration disorder, such difficulties are chronic and cause disruptions in many aspects of their daily lives. Some individuals with SPD will struggle with processing only one sense, while others will struggle with processing multiple senses.

Sensory processing disorder statistics

According to the Sensory Processing Disorder Foundation, at least one in every 20 children is affected by SPD. Furthermore, a research study conducted by the Sensory Processing Disorder Scientific Work Group suggests that one in six children has sensory symptoms that are severe enough to affect his or her ability to perform daily functions.

Causes and risk factors for sensory processing disorder

Like most neurological disorders, a specific cause of sensory processing disorder has not been identified. While research efforts continue to thrive on the topic, most professionals in the field believe that the onset of SPD is the result of a combination of varying factors, including:

Genetic: Preliminary research suggests that sensory processing disorder can be inherited, although no genetic markers have yet been identified.

Physical: Experiments have shown that individuals who experience sensory processing dysfunction have abnormal brain activity when exposed to certain stimuli. In a study conducted at the University of California San Francisco, researchers found that children with SPD have differences in their brain structure that are quantifiable, providing a biological basis for the onset of this disease.

Environmental: Professionals in the field believe that there are a number of environmental factors that can play a role in determining whether or not someone will develop sensory processing disorder. The most prominent of such environmental factors includes not being exposed to appropriate amounts of stimulation during crucial developmental stages.

Risk Factors:

• Having been understimulated or institutionalized during crucial periods of neurological development
• Being exposed to drugs while in utero
• Having food allergies
• Having certain developmental delays or neurological disorders

Signs and symptoms of sensory processing disorder

The symptoms of SPD will vary from person to person in both type and severity. Some individuals with sensory processing disorder will be overly responsive to stimuli, while others may not respond at all. For example, one person may scream in pain when gently touched, while another person may be incapable of feeling pain at all. Different symptoms that may present across the spectrum of SPD severity may include:

Behavioral symptoms:

• Sudden aggressive outbursts
• Throwing tantrums
• Has a difficult time engaging in conversations or play
• Excessively high or excessively low activity level
• Blinks, squints, or rubs one’s eyes frequently
• Resists certain grooming activities
• Illegible handwriting

Physical symptoms:

• Impaired coordination
• Bumping into things
• Overly sensitive to, or incapable of sensing, touch
• Abnormally high or low pain threshold
• Fine and/or gross motor delays
• Avoids eating certain foods due to texture or consistency

Cognitive symptoms:

• Speech and language delays
• Inability to remain focused
• Poor attention span
• Overly sensitive to volume or frequency of sounds
• Becomes easily overstimulated in group settings

Psychosocial symptoms:

• Low sense of self-worth
• Onset of anxiety
• Onset of depression
• Difficulty developing a sense of independence

Effects of sensory processing disorder

While successful treatment options are available for sensory processing disorder, many individuals are misdiagnosed or remain undiagnosed and therefore do not receive appropriate treatment. The long-term effects of untreated SPD may include:

• Difficulty developing and maintaining significant interpersonal relationships
• Academic or occupational failure
• Unemployment
• Social isolation
• Drastically low self-esteem
• Suicidal thoughts and behaviors

Sensory processing disorder and co-occurring disorders

The presence of SPD can occur alongside various other conditions as well, including:

• Autism spectrum disorders
• Anxiety disorders
• Attention-deficit/hyperactivity disorder
• Intellectual disability
• Learning disorders
• Bipolar disorder
• Schizophrenia