What causes learning disabilities? Are they preventable? If I have one, will my child inherit it? Hear what our experts have to say about causality and learning disabilities.
Gail Grodzinsky, Ph.D.:
As of now, no one is certain what causes learning disabilities. It is thought that learning disabilities may be caused by hereditary, teratogenic factors (for instance, alcohol or cocaine use during pregnancy), medical factors (premature birth, diabetes, meningitis of mother or offspring), and/or environmental factors (malnutrition, poor prenatal healthcare). A leading theory among scientists is that learning disabilities stem from subtle disturbances in the way brain structures are formed. Researchers are also studying genetic links.
Sheldon Horowitz, Ed.D.:
Experts aren’t exactly sure what causes learning disabilities. Some possibilities include:
Learning disabilities are NOT caused by economic disadvantage, environmental factors, or cultural differences. In fact, there is frequently no apparent cause for learning disabilities.
David Urion, M.D.:
There appears to be no one cause of learning disabilities. We know that some appear to be hereditary — for example, dyslexia and certain other language-based learning disorders seem to pass through families. In other instances, early brain injury — such as can occur as a consequence of prematurity — is associated with learning disabilities. Certain toxic exposures, such as lead, can produce injury to the developing brain and lead to learning disabilities. Many remain obscure in their origins.
Cheryl Weinstein, Ph.D.:
The most is known about the learning disability known as dyslexia. Individuals with dyslexia do not have the typical pattern of left hemisphere brain organization for reading. Dr. Sally Shaywitz at Yale University (2003) has done remarkable research with functional magnetic resonance imagings (MRIs) showing that dyslexic adults have under-activation of the reading area of the brain and over-activation of brain regions responsible for attention and recognition of sounds. It is no wonder that the adult with a reading disorder is more fatigued after work. Their brain is literally working harder.
More generally, there are multiple factors that cause learning disabilities, including atypical brain organization. Specifically, there may be differences in cells or in the basic “hard-wiring” of the brain. One patient explained that his brain “was wired by a non-union electrician.” There also may be differences in brain development due to metabolic disorders such as maternal diabetes or thyroid disease. Parental alcohol abuse and maternal smoking are well-known agents contributing to childhood learning problems. In addition, there may be stress to the baby during birth when there is sudden lack of oxygen to the baby’s brain (anoxic events).