Developmental disorders can be divided into various types. These include, in particular:
- Developmental disorders of language and speech
- Developmental disorders of academic skills, e.g., reading and spelling disorders (dyslexia), math disorders (dyscalculia)
- Developmental disorders of motor functions
- Pervasive developmental disorders, e.g., autism, Rett syndrome
Developmental disorders of language and speech refer to inadequate language development from the very beginning. They cannot be attributed to
- neurological disorders
- environmental factors (such as moving to a different language area)
- sensory impairments (hearing loss) or
- low intelligence
. It is important to note that children do not all develop at the same rate. Many children develop at a relatively slow pace, at least at certain stages. This does not necessarily indicate a disorder. A disorder is only diagnosed when
- the development of the relevant function proceeds extremely slowly over an extended period of time, or
- related functions are simultaneously impaired.
For example, a language disorder is more likely to be present if, at the same time, pronounced reading or writing problems are evident.
However, if all functions are developing more slowly, this could indicate a general intellectual disability.
What types of language and speech disorders are there?
One specific disorder of language development is what is known as an articulation disorder. It manifests itself in the use of sounds or sound combinations that
- are completely missing,
- are used incorrectly or in the wrong order, or
- are replaced by other sounds.
Articulation disorders are the most common speech development disorders. They occur in approximately 7 percent of 5-year-old boys and 2 percent of 5-year-old girls.
In expressive language disorder, the child is unable to express themselves in a manner appropriate for their age. For example, they cannot speak in age-appropriate sentences. However, their ability to understand others’ speech is normal.
If language comprehension is impaired, the condition is referred to as a receptive language disorder.
Stuttering is a disorder of speech flow. Speech flow is inhibited or interrupted. Those affected often repeat or prolong sounds or syllables. Stuttering occurs in 5 percent of 5-year-old boys and 2 percent of 5-year-old girls.
Cluttering is also a disorder of speech fluency. It is characterized by an extremely arrhythmic and irregular flow of speech, sometimes at a very fast rate.
These developmental disorders include
- reading and spelling disorder (dyslexia) as well as
- mathematics disorder (dyscalculia).
Both disorders are classified as specific learning disabilities, meaning that the child’s other skills are age-appropriate.
Approximately 10 percent of all children are affected by specific learning disabilities, with boys being significantly more affected than girls. Prevalence rates for reading and spelling disorders range between 4 and 7 percent. Up to 6 percent of children are affected by math disorders.
In these developmental disorders, school assessments of the affected functions fall in the lowest range. Additional problems such as inattention or hyperactivity are common.
The disorder does not simply resolve on its own even when the child is offered more support.
Affected children often experience failure, ridicule, and poor performance. This leads to emotional problems such as
- anxiety,
- social behavior disorders,
- psychosomatic symptoms (physical complaints resulting from psychological problems), or
- school refusal.
Reading and Spelling Disorder
Dyslexia manifests itself
- in the omission, transposition, substitution, or addition of letters or words when writing and reading,
- a slow reading speed with marked difficulty getting started and frequent hesitation, as well as
- in the transposition of letters within a word or words within a sentence.
Reading comprehension is also impaired. Affected children may, for example, be unable to paraphrase what they have read or draw their own conclusions from the text. Dyslexia is often preceded by a delay in language development.
In adulthood, difficulties with spelling in particular may persist. Reading ability usually returns to normal.
Dyslexia is a common reading and spelling disorder © photophonie | AdobeStock
In some cases, rather than a reading and spelling disorder, a pure spelling disorder is observed. Reading ability and comprehension remain unaffected.
Therapeutically, the focus is on providing information to parents and children, as well as on exercises to address the impaired functions. In addition, depending on the legal situation in the respective state, options under school law may be available. These include, for example, dyslexia allowances or additional remedial instruction.
Case Study: Reading and Spelling Disorder (Dyslexia)
Nine-year-old Joachim was referred by his pediatrician to the child and adolescent psychiatric outpatient clinic. Until he started school, he had been a cheerful boy developing appropriately for his age. From the start of first grade, despite support from his teacher and mother, he has had great difficulty acquiring reading and writing skills. It is noticeable that Joachim writes the same words very differently on the same page and even has difficulty copying one word from another. In all other subjects, however, he performs very well and participates actively.
His reading and writing problems have persisted for over two and a half years. Joachim is enjoying school less and less. He often sleeps poorly, and in the mornings he frequently complains of stomachaches, which often prevent him from attending school.
Math Disorder (Dyscalculia)
Children with a math disorder master basic math skills at a level significantly below the norm for their age. This includes, for example, the four basic arithmetic operations.
Various errors can occur. Affected children
- For example, they may not understand the concepts behind the arithmetic operations,
- do not understand mathematical expressions and symbols or fail to recognize them,
- cannot recall their multiplication tables, or
- fail to understand number structure and the correct order of numbers.
It is possible that affected children have below-average spatial visualization skills.
Children with this disorder are clumsy in their movements. For example, they have difficulty
- dress themselves,
- tie their shoes,
- using scissors and glue,
- draw or paint.
They are very slow to learn more complex motor skills such as riding a bike or swimming. Due to these deficits, affected children can easily find themselves marginalized in school, sports, and recreational activities.
When making a diagnosis, the doctor checks whether the developmental disorders might also be caused by a visual impairment.
Approximately 1.4 percent of all students are affected, with boys being affected twice as often as girls. Treatment typically involves exercise therapy and training in body awareness.
Autism, like Rett syndrome, is classified as a so-called profound developmental disorder. These disorders are characterized by
- severe impairments in social interaction and communication, as well as
- stereotyped and limited interests or movements
.
Autism
In early-onset autism, which begins before the age of 3, social interactions are severely impaired. Children have difficulty interpreting social cues and show little response to the social context. There is a lack of social or emotional reciprocity, and social play is rare.
Language development is also frequently impaired. The language they do possess is rarely used in social contexts and is employed with little flexibility.
In addition, the children exhibit rigid, highly restricted, and often repetitive behavioral patterns (stereotypies). For example,
- they frequently touch or smell objects, or
- engage in ritualistic activities involving schedules or dates.
In addition to these characteristics, children with autism often exhibit various behavioral issues such as
- fears,
- self-injury (e.g., banging their head against the wall or biting their hand),
- sleep and eating disorders.
A milder form of the condition is Asperger’s syndrome. Here, too, children exhibit
- impaired communication,
- stereotyped behaviors, and
- an idiosyncratic use of language
Intellectual functioning and the development of language skills, however, are not impaired.
Up to 0.1 percent of all children have autism, with boys being affected two to three times as often as girls.
Rett Syndrome
Rett syndrome affects only girls and begins between the 7th and 24th month of life. It is then accompanied by a partial or complete loss of previously acquired motor and language skills. Stereotypical, writhing hand movements are typical.
As the condition progresses, physical developmental abnormalities may also occur. Symptoms such as slowed head growth and epileptic seizures may also appear. Overall, the prognosis is poor and cannot be significantly improved.
