Sensory Defensiveness or Sensory Overload

Did you ever lie awake in bed at night unable to sleep because of the sound of a dripping faucet? Did you ever feel enraged because someone sitting near you was chewing gum and making sounds while dong so? Are you someone who would like to wear a turtle neck sweater during the cold weather but cannot because it feels as though the touch of the fabric on your neck and throat is strangling? Do you react badly by the sudden and unexpected touch of someone, even if its someone you know and love? If you are familiar with any of these experiences you then have a good idea of what sensory defensiveness or sensory overload is all about.

However, what distinguishes you from those who fit the full diagnostic category of sensory defensiveness is that there are multiple stimuli that the sensory defensive person finds intolerable. As a result, daily life is deeply affected because it is difficult or impossible to work, have a relationship or engage in social interaction with other people. The reason for these limitations is that there are so many stimulating factors in the environment that cause real irritation that the individual is distracted and therefore, incapacitated. Many of these people withdraw into social isolation and this isolation as well as the sensitivity to stimuli, are depressing.

In sensory defensiveness, multiple things are experienced as alarming, and are negatively reacted to. It is important to stress that these over stimulating items are minor and do not bother or annoy the average person. For those who with sensory overload, many or all of these things are intolerable. Commonly, there can be a startle response to irritating stimuli. Another common response is extreme anger that other people find disconcerting if not totally unacceptable.

This terrible experience of intolerance can affect everything from the taste and texture of certain foods to many types of sounds, lights and clothing fabrics and even temperature. 

People with this disorder have a lot of variability with regard to what things will be overwhelming and to what degree someone is overwhelmed. It is possible to have a sensory defensiveness to a degree that is mild, moderate or severe.

It is not completely clear what causes this disorder. There is evidence that such factors as Premature Birth, Alcoholism, Drug Addiction, Autism, PTSD, ADHD and Brain Injury due to head trauma, can contribute to the start of hypersensitivity to stimuli.

Conditioning is sometimes used to help people with this condition. This means that they are exposed to very calming stimuli to help counteract the negativer response to things that are irritating. Ultimately the person must learn to use these calming strategies by themselves.

Recent research shows that the part of the brain called the Thalamus might be involved in this hypersensitivity. The Thalamus, located in the middle of the brain, is a kind of relay station for all the sensory information that is relayed via the eyes, ears and other sensory organs. If the thalamus is damaged, it may disrupt the brain's ability to sort out and integrate all the sensory information coming into the brain. The use of fMRI technology and other types of brain scopes, are helping medical science understand what goes wrong in the brains of these people. It is hoped that this will lead to new and more effective techniques for the treatment of this disorder.

It is important to keep in mind that people with this condition are not deliberately behaving badly when they over react to something. This is not something they are choosing to do and would happily change it if they could.

If you know someone who may be experiencing sensory overload, including a child, it is important that they be seen by an MD so that the correct diagnosis can be made and treatment begun. Part of the treatment may include regular visits to a therapist who is expert in using conditioning and relaxation techniques.

Your comments and questions are encouraged.

Allan N. Schwartz, PhD