The Prevention, Diagnosis, and Treatment of Dyslexia
Background: Reading and spelling disorder (dyslexia) is one of the more common specific developmental disorders, with a prevalence of approximately 5%. It is characterized by severe impairment of learning to read and spell.
Methods: We discuss major aspects of the diagnosis, treatment, and prevention of dyslexia on the basis of a selective literature review and the guidelines of the German Society of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy.
Results: 40% to 60% of dyslexic children have psychological manifestations, including anxiety, depression, and attention deficit. The diagnostic assessment of dyslexia consists of a battery of standardized reading and spelling tests and an evaluation of the child’s psychological state, including additional information obtained from parents and teachers. The treatment of dyslexia is based on two main strategies: specific assistance with the impaired learning areas (reading and spelling) and psychotherapy for any coexisting psychological disturbance that may be present. Evaluated preventive strategies are available for use in kindergarten and at home.
Conclusion: The diagnosis of dyslexia should be established with the aid of the multiaxial classification system. The benefit of specific treatment strategies for dyslexia has not yet been demonstrated empirically. Nonetheless, evaluated prevention programs are available in kindergarten that have been found to promote children’s ability to acquire reading and spelling skills in school.
Dyslexia is a specific developmental disorder. Some of the core symptoms of dyslexia can persist into adulthood. Around 5% of children and adolescents suffer from dyslexia (1). The psychological manifestations which often accompany dyslexia have severe effects on children, adolescents and adults with dyslexia.
Dyslexia is characterized by specific, isolated impairment of reading and spelling which cannot be explained by delayed development of cognitive abilities or low intelligence. However, the prejudice that children with dyslexia (also called reading and spelling disorder) are unintelligent and not suitable for grammar school education is very widespread.
The International Classification of Mental Disorders (2) and the Diagnostic and Statistical Manual of Mental Disorders (3) define diagnostic criteria which can be used to diagnose dyslexia and, in the case of ICD-10, also to diagnose isolated spelling disorder. Although both classification systems list dyslexia as a mental disorder, comparable to language development disorders and motor development disorders, the German public healthcare system does not recognize dyslexia as an illness, despite considerable protests from parents and sufferers, who are obliged to pay treatment costs themselves. A possible reason for this is that until the 1980s dyslexia was thought to be caused by educational methods. However, the results of basic research conducted in the last 30 years show that dyslexia has neurobiological correlates and that genetic factors affect reading and spelling ability (e1–e4).
This selective literature review is based on the guidelines of the German Society of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy.
The aims of this overview are as follows:
- To convey an understanding of the complexity of diagnosis
- To identify the ways in which support can be provided for dyslexia sufferers.
Reading disorder is characterized by very significantly reduced reading speed. Children with reading disorder often require two to three times as much time as other children, or more, to read text. Slower reading leads to great difficulty understanding what has been read, particularly when reading longer sentences.
Associating individual letters with their corresponding sounds is very slow, and mistakes are often made. In place of words which are difficult to read, children with reading disorder tend to read other words with similar letters. Some children manage to deduce the content of a sentence on the basis of the other words it contains even when individual words are read incorrectly (e.g. hammer instead of matter). It is therefore very important that diagnosis take into account not only reading comprehension but also the speed with which individual words are read aloud.
Limited reading speed is also the main symptom of reading disorder in adults (4). This occurs in particular with complex, polysyllabic, and rare words. In stressful situations, e.g. reading forms at an official office or in front of colleagues, symptoms increase. Reading disorder also manifests itself in counting (e.g. reading math word problems) and when learning foreign languages.
Spelling disorder is characterized by a significantly increased number of spelling errors. Children with spelling disorder usually spell only 10% of 40 test words correctly. In free writing, words are avoided when children suspect that they cannot spell them correctly. This is often perceived as limited vocabulary or a lack of linguistic ability. However, it is usually a compensation strategy to avoid spelling errors, which are still often corrected in red pen, with negative comments from teachers.
The development of the ability to spell comes in stages. First of all, children begin to spell phonetically, e.g. foto instead of photo or boks instead of box (Figure 1 gif ppt). It usually takes a year to learn all sound-letter associations. Children with spelling disorder often take two years. The next stage of spelling development is orthographically correct writing. This includes issues such as correct use of capital and lower-case letters, suffixes (asked, not askt) and correct spelling of word roots (happen, not hapen, because the first vowel is short). The basics of correct spelling have usually been acquired before the end of the fourth year of school in Germany (age 10 years). Children with spelling disorder have great difficulties spelling words correctly, even in adulthood.
It is impossible to define subgroups of dyslexia according to etiology. Nor are there any spelling errors which are typical of dyslexia, but rather errors which can be assigned to individual stages of development.
40% to 60% of children and adolescents with dyslexia experience psychological problems. This is significantly higher than the general prevalence of psychological disorders, which according to current data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) is between 5% and 18%, depending on the diagnostic criteria and clinical symptoms used for classification (e5, e6). Children with dyslexia experience more negative thoughts, depression, gloomy moods, and school-related anxiety as early as primary school. They often feel excluded, disapproved of by teachers, and rejected.
The rate of world-weary thoughts and suicide attempts in adolescents with dyslexia is three times as high as that of adolescents of the same age without dyslexia (5, 6). The rate of depressive disorders in adolescents with dyslexia is twice as high, and anxiety disorders are as much as three times as common (7). The most common concurrent disorders at primary school age include attention deficit hyperactivity disorder (ADHD) (approximately 20%).
In addition, due to significantly improved diagnosis, dyscalculia is being identified more and more frequently (prevalence of dyscalculia: approximately 5% [e7]). ICD-10 classifies dyscalculia as combined disorders involving abilities learned in school (F81.3). For many years it was thought that those with significant problems reading and spelling must be good with numbers. This idea was not borne out by empirical research. In fact, approximately 20% to 40% of children with reading and/or spelling disorder also suffer from dyscalculia (7).
Although ICD-10 and DSM-IV are based on a clinical picture characterized by impaired development of reading and spelling, current research shows that there are three separate disorders (8):
- Combined reading and spelling disorder, or dyslexia
- Reading disorder alone
- Spelling disorder alone.
The prevalence of combined reading and spelling disorder is 8%, that of spelling disorder alone 6% and that of isolated reading disorder 7%. It appears that different neurocognitive deficits underlie each of these disorders. However, as yet there are no valid research results on this (8).
Studies involving large epidemiological samples have shown repeatedly that dyslexia is two to three times as common in boys as in girls. When differentiating between reading disorder and spelling disorder, it was shown that boys exhibit spelling problems more frequently but are affected by reading disorder in similar numbers to girls (8, 9).
Diagnosis of dyslexia and of isolated reading disorder and spelling disorder is complex and relies on the following (the list is non-exhaustive) in addition to the core symptoms of reading and/or spelling disorder:
- Psychiatric disorder (ADHD)
- The child’s cognitive ability (intelligence)
- Chronic diseases (diabetes mellitus)
- Negative psychosocial factors (significant distressing factors at school such as bullying)
- The child’s psychosocial functional level (interaction with others of the same age).
These functional areas are represented for classification in the multiaxial classification system for mental disorders (MAS, 10) and its six axes. Developmental disorders are represented on axis II, psychiatric illnesses on axis I, intelligence on axis III, physical diseases on axis IV, psychosocial factors on axis V, and psychosocial functional level on axis VI.
Reading and spelling diagnostics
Diagnosis of reading ability should cover speed, accuracy and comprehension when reading. There are currently standardized tests available for this for German school years 1 through 6 (Table 1 gif ppt). A combination of various tests is needed to test word reading and reading comprehension. This involves individual testing of a child by an examiner. The child’s performance is compared to that of children in the same school year. There are often standards for particular months, which means that tests should only be used during these limited time periods. Tests which were standardized more than ten years ago should not be used. There are also “reading screenings,” suitable for group tests in schools but not for standard diagnosis.
There are currently standardized tests for all school years to examine spelling ability (Table 2 gif ppt). In these tests, children write down dictated words in sentences with gaps (Figure 1). Depending on age and grade, children are required to write down more than 20 words. There is no time limit for the test. These tests are also standardized for limited periods of time. This means that spelling tests should only be used when there are standards for the time period during which testing can be conducted.
To describe the cognitive ability of a schoolchild with dyslexia, a test with as broad a scope as possible should be selected. One option is the WISC-IV (Wechsler Intelligence Scale for Children) (German version: HAWIK-IV, Hamburg-Wechsler intelligence test for children) (11), which has been standardized for children aged 5 to 16. In addition to linguistic abilities, this test includes logical thought, processing speed, and memory. The results profile it provides allows for differential diagnosis of reading and spelling weaknesses due to lower intelligence and dyslexia with cognitive abilities of at least average level. HAWIK-IV is conducted with an individual schoolchild. The length of the test depends on the child’s attention span, concentration, and motivation. It is often necessary to divide the extensive testing into two periods. To ensure that children’s results are fair, it is essential that testing be carried out in the morning, as this is when performance is usually highest.
In addition to developmental history, school history is also very important. It is helpful to obtain information on development in reading, spelling, counting, and other school subjects from teachers. The development of written language skills can be established with the help of samples of the child’s writing (e.g. stories, free writing, dictation), possibly from several different school years. In addition to examination, questionnaires and clinical interviews can be used to assess emotional development, anxieties, and depression (12). To investigate how schoolchildren assess their own abilities at school, there are self-assessment scales for rating students' academic self concept (13). Scales to measure motivation for learning and performance (14) are a valid, reliable method for assessing motivation in school, use of avoidance strategies, and attainment of targets.
Providing a diagnosis
The results of reading and spelling tests give percentage rankings that can be used to compare an individual child’s performance with that of other children in the same school year. A percentage ranking of 15 means that 85% of children in the same school year score better on the test in question. To be diagnosed with dyslexia, a child’s reading and spelling performance must be well below average. This means a percentage ranking <16, which corresponds to one standard deviation below the mean. Both MAS (ICD-10) and DSM-IV require not only a divergence from the class or age level, but also a reading and spelling ability different from the level expected on the basis of the child’s intelligence. In practice, this means that reading and spelling performance as measured in individual tests is compared to intelligence quotient (IQ). As there is a medium-high correlation between reading, spelling and IQ, the use of a divergence criterion in children with low or high intelligence does not yield meaningful diagnostic results. In children with high intelligence (e.g. an IQ of 115), a spelling performance of percentage ranking (PR) <55 (the average is PR 16–84) represents a divergence of 1.5 standard deviations. Because of this, in practice a regression criterion must be used (15). This criterion, which is more appropriate methodologically, means that for the given example spelling test performance must be less than percentage ranking 14 (i.e. in the below-average area). Table 3 (gif ppt) shows the critical percentage rankings below which reading and/or spelling disorder should be diagnosed, according to individuals’ overall IQ. Table 3 shows critical divergences for both criteria (columns 1 and 2 for a divergence of 1.5 standard deviations between spelling and IQ, and columns 3 and 4 for 1 standard deviation). In other words, an individual’s result must be less than the value for a given percentage ranking shown in Table 3 in order to meet the criterion at a particular IQ and so give a diagnosis of dyslexia.
However, diagnosis must not be based on reading and spelling test scores alone. In adolescents with dyslexia or children who have received treatment, the critical borderline value may be narrowly missed, but this does not mean that the disorder has been cured. Diagnostic decisions must take a child’s overall psychosocial development into account. This includes support and treatment received to date, the child’s integration in school, relations with classmates and friends, and the child’s family situation in terms of stress and support.
Treatment consists initially of defining the disorder, advising parents, and possibly also advising teachers (16). Subsequent treatment depends on the severity of dyslexia and psychological symptoms or concurrent disorders. Drug treatment is not beneficial for dyslexia. Only if a dyslexia sufferer also has attention deficit hyperactivity disorder (ADHD) can drug treatment for ADHD also improve learning abilities inside and outside school.
Defining the disorder, its causes, and treatment options is usually a great relief to parents. Diagnosis often takes months to years, during which time parents, usually the mother, have tried to support their child via daily practice at home. Hours spent together every day on homework, regular (usually frustrating) dictation exercises, the child’s unwillingness to study, together with despair at spelling errors in so many words in samples or tests despite so much practice, lead to constant depression in the child and feelings of failure in parents.
In addition, parents often receive reports from teachers to the effect that their child might benefit from more practice at home. If parents are then told in advice sessions that they have not failed, that their child finds it significantly harder than other children to learn to read and spell because of neurobiological deficits, this comes as a great relief to parents. Children themselves must also have the disorder explained to them and thereby have their stress relieved.
Advice for teachers serves to explain the child’s psychological stress and provides an opportunity to consider together how the child can become better integrated at school. The dyslexia diagnosis must also be reported. In some German federal regions dyslexia is recognized by educational law, which has consequences for inschool support and awarded grades.
Dyslexia treatment has two components: treatment of core problems with reading and spelling, and treatment of any concurrent psychological disorders (16).
Child and adolescent psychotherapy is available to treat psychological disorders. This aims primarily to reduce children’s symptoms and improve their individual development.
To the great bewilderment of all parents, dyslexia treatment is not covered by statutory health insurance in Germany. As a result, parents must seek specialist help on the free market. As there is no nationally recognized training for dyslexia therapists, the parents’ association German Association for Dyslexia and Dyscalculia (Bundesverband Legasthenie und Dyskalkulie, BVL) (17) has begun a program to certify training establishments. The term BVL-certified dyslexia therapist, which is granted to graduates of the corresponding training institutes, is associated with extensive theoretical and practical training. All other titles, such as dyslexia therapist, are unprotected and do not necessarily guarantee suitable qualification.
Reading support depends on an individual child’s development. On the basis of detailed analysis of developmental status in reading, reading support should be provided regularly, at least once a week for at least a year. In addition to this therapy, establishing a reading-friendly family environment with frequent reading sessions and reading together can also substantially boost reading development. Only a few types of reading support have been empirically investigated.
Spelling support must be given separately from reading support. As with reading support, individual developmental status must be determined at the outset. Support is then designed around this. Beginning with support in phonics (spelling individual sounds), children learn regular trends in spelling. For example, in English the diphthong
However, despite regular, intensive support most children with dyslexia achieve only slight improvement in their reading and spelling. The reasons for this are not well understood. Attempts are now being made to better understand the processes which are disrupted in these children by recording neurobiological correlates during treatment.
An essential part of treatment is therefore psychotherapy. Children suffering from anxiety and depression can be significantly helped by such treatment. If a sufferer also has ADHD, drug treatment is also indicated when the disorder is severe, in addition to psychotherapy.
Because of the often chronic progression of the disorder, together with substantial psychosocial limitations and psychological stress, preventing reading and spelling difficulties is very important. As primary prevention, schemes which build on preschool support for linguistic abilities have been developed. For several years, an early support program named “Hear, Listen, and Learn” (Hören, lauschen, lernen) (e8) has been used in kindergartens. It is used with small groups of children a half-year before they start school, led by a kindergarten teacher (23). The focus is on language games, rhyme recognition, clapping syllables, and sound recognition. The program’s preventive effect for written language development has been confirmed in long-term studies. This early support also reduces the risk for children who are at risk of dyslexia (e9–e11). However, it is only effective when kindergarten teachers are well trained in how to use the method and correspondingly well motivated.
The significance of families in supporting language skills in preschoolers has long been known. The “Let’s read!” program (Lass uns lesen!) links preschool language support with reading aloud together and encouraging knowledge of the alphabet (24). In the last half-year before children start school, one parent carries out 15 minutes of activities with the child every day. With the help of three activity books and extensive materials (Figure 3 gif ppt), there are games and tasks involving rhyme recognition and creation, syllables, knowledge of words and sentences, recognition of the beginnings of words and syllables, letter-sound associations, and the ends of words and syllables. These activities are great fun for children, and the scheme also prepares them for school, as they are faced with specific tasks. The efficacy of supporting phonological abilities and language skills by reading together was assessed in two evaluation studies which show that children’s language and sound recognition abilities are increased by the Let’s read! program, and as a result the basis for learning to read and spell is improved (25, e12).
Conflict of interest statement
The authors declare that no conflict of interest exists according to the guidelines of the International Committee of Medical Journal Editors.
Manuscript received on 21 May 2010, revised version accepted on 16 July 2010.
Translated from the original German by Caroline Devitt, MA.
Prof. Dr. med. Gerd Schulte-Körne
Direktor der Klinik für Kinder- und Jugendpsychiatrie,
Psychosomatik und Psychotherapie, Klinikum der Universität München
80336 München, Germany
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