The first descriptions of language disorders emerged in the early 1800s and referred to children who had a poor understanding and use of speech. By 1998, communication disorders such as language disorders were known to affect as many as one in 10 people in the United States.
According to the Gale Encyclopedia of Children's Health (2006), speech and language problems are extremely common. Disorders range from the slow acquisition of language to sound substitution, stuttering, the inability to understand language or to speak at all. The federal Agency for Healthcare Research and Quality estimated in 2002 that communication disorders cost the United States between $30 billion and $154 billion annually in lost productivity and funds spent on special education, medical care and remediation.
A disorder can be verbal or written, for example dyslexia. When language difficulties occur and no other issues are identified as the cause, such as hearing impairment, neuromotor dysfunction, environmental deprivation, autism or emotional disturbance, then the diagnosis may well be diagnosed as a language disorder. This commonly affects the ability to process sounds into syllables and words. Individuals with this diagnosis may not grasp the proper use of words, are often confused about their meaning, have difficulty in expressing ideas and thoughts and find it challenging to remember numbers and letters in sequence.
Language disorders can be described as either developmental or acquired. In a developmental disorder there is no obvious point of onset or identifiable neurological basis. An acquired disorder may be caused by an identified neurological condition or be traced to a point of onset, such as psychological trauma. Developmental language disorders affect a child's functional language skills. For example, they may be unable to use language properly and can appear direct and change the topic of conversation abruptly.
Studies have shown that developmental language disorders are often inherited, as specific disorders can present in families with a history of learning or language problems. Familial language disorders may be genetic or caused by environmental factors. For example, the child may experience greater exposure to deviant language in families with a history of language disorders. In the developmental stages when language is acquired, the need to communicate effectively may lead to parents using overly simplistic language. This could create further problems for the development of speech.
An acquired language disorder, also known as aphasia, has an underlying neurological cause. It is due to brain damage resulting from cerebral palsy, stroke, tumor or head trauma affecting the parts of the brain responsible for language function. For example, Broca's area is located in the left frontal lobe and damage to this area affects language fluency. People affected by this may use shortened sentences and demonstrate an impaired flow of speech or lack of intonation. This is also known as Broca's aphasia. Damage to an area in the left temporal lobe is called the Wernicke's area and results in rapid speech where individuals sometimes invent words.
A language disorder can have far-reaching effects, such as social and educational isolation. It may cause frustration and anxiety in children who are unable to communicate with others and perceive their own differences from their peers. Their frustration can lead to other problems such as self-abusive behavior or they might become withdrawn and show signs of depressive behavior. Delayed diagnosis of language disorders can prolong the agony for both the child and the family. Parents or carers can sometimes find themselves blamed by professionals in this field, who attribute delayed speech to parenting issues where the child is "nannied" and discouraged from developing their communications skills.
Treatment for language disorders is usually undertaken by a speech therapist in conjunction with the child's family and physician, with educational support. This condition is easier to tackle when diagnosed early because language and communication skills are best learnt before the age of five. At this age it is widely believed that corrective treatments are more readily accepted.
In early childhood, language disorders may be identified due to the disparity between the child's speech development and other children of the same age, particularly if the child does not naturally outgrow the stage where "baby talk" would be normally expected. Common indicators include very low attention levels or lack of organizational skills, coupled with difficulty in getting others to understand what the child is trying to communicate. The child may also be able to hear or see a word but have difficulty understanding its meaning.