Learning Disabilities from the National Institute of Mental Health
Imagine having important needs and ideas to communicate, but being unable to express them. Perhaps feeling bombarded by sights and sounds, unable to focus your attention. Or trying to read or add but not being able to make sense of the letters or numbers.
You may not need to imagine. You may be the parent or teacher of a child experiencing academic problems, or have someone in your family diagnosed as learning disabled. Or possibly as a child you were told you had a reading problem called dyslexia or some other learning handicap.
Although different from person to person, these difficulties make up the common daily experiences of many learning disabled children, adolescents, and adults. A person with a learning disability may experience a cycle of academic failure and lowered self-esteem. Having these handicaps--or living with someone who has them--can bring overwhelming frustration.
But the prospects are hopeful. It is important to remember that a person with a learning disability can learn. The disability usually only affects certain limited areas of a child's development. In fact, rarely are learning disabilities severe enough to impair a person's potential to live a happy, normal life.
This booklet is provided by the National Institute of Mental Health (NIMH), the Federal agency that supports research nationwide on the brain, mental illnesses, and mental health. Scientists supported by NIMH are dedicated to understanding the workings and interrelationships of the various regions of the brain, and to finding preventions and treatments to overcome brain dysfunctions that handicap people in school, work, and play.
The booklet provides up--to-date information on learning disabilities and the role of NIMH-sponsored research in discovering underlying causes and effective treatments. It describes treatment options, strategies for coping, and sources of information and support. Among these sources are doctors, special education teachers, and mental health professionals who can help identify learning disabilities and recommend the right combination of medical, psychosocial, and educational treatment.
In this booklet, you'll also read the stories of Susan, Wallace, and Dennis, three people who have learning disabilities. Although each had a rough start, with help they learned to cope with their handicaps. You'll see their early frustrations, their steps toward getting help, and their hopes for the future.
The stories of Susan, Wallace, and Dennis are representative of people with learning disabilities, but the characters are not real. Of course, people with learning disabilities are not all alike, so these stories may not fit any particular individual.
- What is a learning disability?
- What are the types of learning disabilities?
- What causes learning disabilities?
- Are learning disabilities related to differences in the brain?
- How are learning disabilities first identified?
- How are learning disabilities formally diagnosed
- What are the education options?
- Is medication available?
- How do families learn to cope?
- Can learning disabilities be outgrown or cured?
- What aid does the Government offer?
- What hope does research offer?
What are sources of information and support?
At age 14, Susan still tends to be quiet. Ever since she was a child, she was so withdrawn that people sometimes forgot she was there. She seemed to drift into a world of her own. When she did talk, she often called objects by the wrong names. She had few friends and mostly played with dolls or her little sister. In school, Susan hated reading and math because none of the letters, numbers or "+" and "-" signs made any sense. She felt awful about herself. She'd been told--and was convinced--that she was retarded.
Wallace has lived 46 years, and still has trouble understanding what people say. Even as a boy, many words sounded alike. His father patiently said things over and over. But whenever his mother was drunk, she flew into a rage and spanked him for not listening. Wallace's speech also came out funny. He had such problems saying words that in school his teacher sometimes couldn't understand him. When classmates called him a "dummy," his fists just seemed to take over.
Dennis is 23 years old and still seems to have too much energy. But he had always been an overactive boy, sometimes jumping on the sofa for hours until he collapsed with exhaustion. In grade school, he never sat still. He interrupted lessons. But he was a friendly, well-meaning kid, so adults didn't get too angry. His academic problems became evident in third grade, when his teacher realized that Dennis could only recognize a few words and wrote like a first grader. She recommended that Dennis repeat third grade, to give him time to "catch up." After another full year, his behavior was still out of control, and his reading and writing had not improved.
Unlike other disabilities, such as paralysis or blindness, a learning disability (LD) is a hidden handicap. A learning disability doesn't disfigure or leave visible signs that would invite others to be understanding or offer support. A woman once blurted to Wallace, "You seem so intelligent--you don't look handicapped!"
LD is a disorder that affects people's ability to either interpret what they see and hear or to link information from different parts of the brain. These limitations can show up in many ways--as specific difficulties with spoken and written language, coordination, self-control, or attention. Such difficulties extend to schoolwork and can impede learning to read or write, or to do math.
Learning disabilities can be lifelong conditions that, in some cases, affect many parts of a person's life: school or work, daily routines, family life, and sometimes even friendships and play. In some people, many overlapping learning disabilities may be apparent. Other people may have a single, isolated learning problem that has little impact on other areas of their lives.
"Learning disability" is not a diagnosis in the same sense as "chickenpox" or "mumps." Chickenpox and mumps imply a single, known cause with a predictable set of symptoms. Rather, LD is a broad term that covers a pool of possible causes, symptoms, treatments, and outcomes. Partly because learning disabilities can show up in so many forms, it is difficult to diagnose or to pinpoint the causes. And no one knows of a pill or remedy that will cure them.
Not all learning problems are necessarily learning disabilities. Many children are simply slower in developing certain skills. Because children show natural differences in their rate of development, sometimes what seems to be a learning disability may simply be a delay in maturation. To be diagnosed as a learning disability, specific criteria must be met.
The criteria and characteristics for diagnosing learning disabilities appear in a reference book called the DSM (short for the Diagnostic and Statistical Manual of Mental Disorders). The DSM diagnosis is commonly used when applying for health insurance coverage of diagnostic and treatment services.
Learning disabilities can be divided into three broad categories:
- Developmental speech and language disorders
- Academic skills disorders
- "Other," a catch-all that includes certain coordination disorders and learning handicaps not covered by the other terms
Each of these categories includes a number of more specific disorders.
Developmental Speech and Language Disorders
Speech and language problems are often the earliest indicators of a learning disability. People with developmental speech and language disorders have difficulty producing speech sounds, using spoken language to communicate, or understanding what other people say. Depending on the problem, the specific diagnosis may be:
- Developmental articulation disorder
- Developmental expressive language disorder
- Developmental receptive language disorder
Developmental Articulation Disorder -- Children with this disorder may have trouble controlling their rate of speech. Or they may lag behind playmates in learning to make speech sounds. For example, Wallace at age 6 still said "wabbit" instead of "rabbit" and "thwim" for "swim." Developmental articulation disorders are common. They appear in at least 10 percent of children younger than age 8. Fortunately, articulation disorders can often be outgrown or successfully treated with speech therapy.
Developmental Expressive Language Disorder -- Some children with language impairments have problems expressing themselves in speech. Their disorder is called, therefore, a developmental expressive language disorder. Susan, who often calls objects by the wrong names, has an expressive language disorder. Of course, an expressive language disorder can take other forms. A 4-year-old who speaks only in two-word phrases and a 6-year-old who can't answer simple questions also have an expressive language disability.
Developmental Receptive Language Disorder -- Some people have trouble understanding certain aspects of speech. It's as if their brains are set to a different frequency and the reception is poor. There's the toddler who doesn't respond to his name, a preschooler who hands you a bell when you asked for a ball, or the worker who consistently can't follow simple directions. Their hearing is fine, but they can't make sense of certain sounds, words, or sentences they hear. They may even seem inattentive. These people have a receptive language disorder. Because using and understanding speech are strongly related, many people with receptive language disorders also have an expressive language disability.
Of course, in preschoolers, some misuse of sounds, words, or grammar is a normal part of learning to speak. It's only when these problems persist that there is any cause for concern.
Academic Skills Disorders
Students with academic skills disorders are often years behind their classmates in developing reading, writing, or arithmetic skills. The diagnoses in this category include:
- Developmental reading disorder
- Developmental writing disorder
- Developmental arithmetic disorder
Developmental Reading Disorder -- This type of disorder, also known as dyslexia, is quite widespread. In fact, reading disabilities affect 2 to 8 percent of elementary school children.
When you think of what is involved in the "three R's"--reading, 'riting, and 'rithmetic--it's astounding that most of us do learn them. Consider that to read, you must simultaneously:
- Focus attention on the printed marks and control eye movements across the page
- Recognize the sounds associated with letters
- Understand words and grammar
- Build ideas and images
- Compare new ideas to what you already know
- Store ideas in memory
Such mental juggling requires a rich, intact network of nerve cells that connect the brain's centers of vision, language, and memory.
A person can have problems in any of the tasks involved in reading. However, scientists found that a significant number of people with dyslexia share an inability to distinguish or separate the sounds in spoken words. Dennis, for example, can't identify the word "bat" by sounding out the individual letters, b-a-t. Other children with dyslexia may have trouble with rhyming games, such as rhyming "cat" with "bat." Yet scientists have found these skills fundamental to learning to read. Fortunately, remedial reading specialists have developed techniques that can help many children with dyslexia acquire these skills.
However, there is more to reading than recognizing words. If the brain is unable to form images or relate new ideas to those stored in memory, the reader can't understand or remember the new concepts. So other types of reading disabilities can appear in the upper grades when the focus of reading shifts from word identification to comprehension.
Developmental Writing Disorder -- Writing, too, involves several brain areas and functions. The brain networks for vocabulary, grammar, hand movement, and memory must all be in good working order. So a developmental writing disorder may result from problems in any of these areas. For example, Dennis, who was unable to distinguish the sequence of sounds in a word, had problems with spelling. A child with a writing disability, particularly an expressive language disorder, might be unable to compose complete, grammatical sentences.
Developmental Arithmetic Disorder -- If you doubt that arithmetic is a complex process, think of the steps you take to solve this simple problem: 25 divided by 3 equals ?
Arithmetic involves recognizing numbers and symbols, memorizing facts such as the multiplication table, aligning numbers, and understanding abstract concepts like place value and fractions. Any of these may be difficult for children with developmental arithmetic disorders. Problems with numbers or basic concepts are likely to show up early. Disabilities that appear in the later grades are more often tied to problems in reasoning.
Many aspects of speaking, listening, reading, writing, and arithmetic overlap and build on the same brain capabilities. So it's not surprising that people can be diagnosed as having more than one area of learning disability. For example, the ability to understand language underlies learning speak. Therefore, any disorder that hinders the ability to understand language will also interfere with the development of speech, which in turn hinders learning to read and write. A single gap in the brain's operation can disrupt many types of activity.
"Other" Learning Disabilities
The DSM also lists additional categories, such as "motor skills disorders" and "specific developmental disorders not otherwise specified." These diagnoses include delays in acquiring language, academic, and motor skills that can affect the ability to learn, but do not meet the criteria for a specific learning disability. Also included are coordination disorders that can lead to poor penmanship, as well as certain spelling and memory disorders.
Nearly 4 million school-age children have learning disabilities. Of these, at least 20 percent have a type of disorder that leaves them unable to focus their attention.
Some children and adults who have attention disorders appear to daydream excessively. And once you get their attention, they're often easily distracted. Susan, for example, tends to mentally drift off into a world of her own. Children like Susan may have a number of learning difficulties. If, like Susan, they are quiet and don't cause problems, their problems may go unnoticed. They may be passed along from grade to grade, without getting the special assistance they need.
In a large proportion of affected children--mostly boys--the attention deficit is accompanied by hyperactivity. Dennis is an example of a person with attention deficit hyperactivity disorder--ADHD. They act impulsively, running into traffic or toppling desks. Like young Dennis, who jumped on the sofa to exhaustion, hyperactive children can't sit still. They blurt out answers and interrupt. In games, they can't wait their turn. These children's problems are usually hard to miss. Because of their constant motion and explosive energy, hyperactive children often get into trouble with parents, teachers, and peers.
By adolescence, physical hyperactivity usually subsides into fidgeting and restlessness. But the problems with attention and concentration often continue into adulthood. At work, adults with ADHD often have trouble organizing tasks or completing their work. They don't seem to listen to or follow directions. Their work may be messy and appear careless.
Attention disorders, with or without hyperactivity, are not considered learning disabilities in themselves. However, because attention problems can seriously interfere with school performance, they often accompany academic skills disorders.
Understandably, one of the first questions parents ask when they learn their child has a learning disorder is "Why? What went wrong?"
Mental health professionals stress that since no one knows what causes learning disabilities, it doesn't help parents to look backward to search for possible reasons. There are too many possibilities to pin down the cause of the disability with certainty. It is far more important for the family to move forward in finding ways to get the fight help.
Scientists, however, do need to study causes in an effort to identify ways to prevent learning disabilities.
Once, scientists thought that all learning disabilities were caused by a single neurological problem. But research supported by NIMH has helped us see that the causes are more diverse and complex. New evidence seems to show that most learning disabilities do not stem from a single, specific area of the brain, but from difficulties in bringing together information from various brain regions.
Today, a leading theory is that learning disabilities stem from subtle disturbances in brain structures and functions. Some scientists believe that, in many cases, the disturbance begins before birth.
Errors in Fetal Brain Development
Throughout pregnancy, the fetal brain develops from a few all-purpose cells into a complex organ made of billions of specialized, interconnected nerve cells called neurons. During this amazing evolution, things can go wrong that may alter how the neurons form or interconnect.
In the early stages of pregnancy, the brain stem forms. It controls basic life functions such as breathing and digestion. Later, a deep ridge divides the cerebrum--the thinking part of the brain--into two halves, a right and left hemisphere. Finally, the areas involved with processing sight, sound, and other senses develop, as well as the areas associated with attention, thinking, and emotion.
As new cells form, they move into place to create various brain structures. Nerve cells rapidly grow to form networks with other parts of the brain. These networks are what allow information to be shared among various regions of the brain.
Throughout pregnancy, this brain development is vulnerable to disruptions. If the disruption occurs early, the fetus may die, or the infant may be born with widespread disabilities and possibly mental retardation. If the disruption occurs later, when the cells are becoming specialized and moving into place, it may leave errors in the cell makeup, location, or connections. Some scientists believe that these errors may later show up as learning disorders.
Other Factors That Affect Brain Development
Through experiments with animals, scientists at NIMH and other research facilities are tracking clues to determine what disrupts brain development. By studying the normal processes of brain development, scientists can better understand what can go wrong. Some of these studies are examining how genes, substance abuse, pregnancy problems, and toxins may affect the developing brain.
Genetic Factors -- The fact that learning disabilities tend to run in families indicates that there may be a genetic link. For example, children who lack some of the skills needed for reading, such as hearing the separate sounds of words, are likely to have a parent with a related problem. However, a parent's learning disability may take a slightly different form in the child. A parent who has a writing disorder may have a child with an expressive language disorder. For this reason, it seems unlikely that specific learning disorders are inherited directly. Possibly, what is inherited is a subtle brain dysfunction that can in turn lead to a learning disability.
There may be an alternative explanation for why LD might seem to run in families. Some learning difficulties may actually stem from the family environment. For example, parents who have expressive language disorders might talk less to their children, or the language they use may be distorted. In such cases, the child lacks a good model for acquiring language and therefore, may seem to be learning disabled.
Tobacco, Alcohol, and Other Drug Use -- Many drugs taken by the mother pass directly to the fetus. Research shows that a mother's use of cigarettes, alcohol, or other drugs during pregnancy may have damaging effects on the unborn child. Therefore, to prevent potential harm to developing babies, the U.S. Public Health Service supports efforts to make people aware of the possible dangers of smoking, drinking, and using drugs.
Scientists have found that mothers who smoke during pregnancy may be more likely to bear smaller babies. This is a concern because small newborns, usually those weighing less than 5 pounds, tend to be at risk for a variety of problems, including learning disorders.
Alcohol also may be dangerous to the fetus' developing brain. It appears that alcohol may distort the developing neurons. Heavy alcohol use during pregnancy has been linked to fetal alcohol syndrome, a condition that can lead to low birth weigh, intellectual impairment, hyperactivity, and certain physical defects. Any alcohol use during pregnancy, however, may influence the child's development and lead to problems with learning, attention, memory, or problem solving. Because scientists have not yet identified "safe" levels, alcohol should be used cautiously by women who are pregnant or who may soon become pregnant.
Drugs such as cocaine--especially in its smokable form known as crack--seem to affect the normal development of brain receptors. These brain cell parts help to transmit incoming signals from our skin, eyes, and ears, and help regulate our physical response to the environment. Because children with certain learning disabilities have difficulty understanding speech sounds or letters, some researchers believe that learning disabilities, as well as ADHD, may be related to faulty receptors. Current research points to drug abuse as a possible cause of receptor damage.
Problems During Pregnancy or Delivery -- Other possible causes of learning disabilities involve complications during pregnancy. In some cases, the mother's immune system reacts to the ferns and attacks it as if it were an infection. This type of disruption seems to cause newly formed brain cells to settle in the wrong part of the brain. Or during delivery, the umbilical cord may become twisted and temporarily cut off oxygen to the fetus. This, too, can impair brain functions and lead to LD.
Toxins in the Child's Environment -- New brain cells and neural networks continue to be produced for a year or so after the child is born. These cells are vulnerable to certain disruptions, also.
Researchers are looking into environmental toxins that may lead to learning disabilities, possibly by disrupting childhood brain development or brain processes. Cadmium and lead, both prevalent in the environment, are becoming a leading focus of neurological research. Cadmium, used in making some steel products, can get into the soil, then into the foods we eat. Lead was once common in paint and gasoline, and is still present in some water pipes. A study of animals sponsored by the National Institutes of Health showed a connection between exposure to lead and learning difficulties. In the study, rats exposed to lead experienced changes in their brainwaves, slowing their ability to learn. The learning problems lasted for weeks, long after the rats were no longer exposed to lead.
In addition, there is growing evidence that learning problems may develop in children with cancer who had been treated with chemotherapy or radiation at an early age. This seems particularly true of children with brain tumors who received radiation to the skull.
In comparing people with and without learning disabilities, scientists have observed certain differences in the structure and functioning of the brain. For example, new research indicates that there may be variations in the brain structure called the planum temporale, a language-related area found in both sides of the brain. In people with dyslexia, the two structures were found to be equal in size. In people who are not dyslexic, however, the left planum temporale was noticeably larger. Some scientists believe reading problems may be related to such differences.
With more research, scientists hope to learn precisely how differences in the structures and processes of the brain contribute to learning disabilities, and how these differences might be treated or prevented.
- Learning disabilities can be divided into three broad categories: