Language Disorders: Types, Causes, Prevalence and Important Assessment Tools

The aim of this study is to understand language disorders, its possible causes and prevalence rate and to study relevant tools that play important role in identifying its presence. It does not cover speech disorders that form part of communication disorders. According to the DSM 5, the key features of language disorder are difficulties in acquisition and use of language due to deficits in the comprehension or production of vocabulary, sentence structure and discourse. There are difficulties in expressive ability - the production of vocal, gestural or verbal signals and receptive ability the process of receiving and comprehending language messages. In a study by Konadath, Suma, Jayaram, Sandeep, Mahima, and Shreyank (2013), it was found that prevalence of individuals with speech and language disorders was 9.42%. It was more prevalent in males than females and reading and writing difficulties were most commonly occurring problems among those suffering from speech and language disorders. Although no single cause has been found to explain language disorders, there is clear evidence of underlying cognitive deficits which are genetic in nature. Because language disorders often manifest in other areas of academics such as reading and writing, early identification can help in early intervention and remediation, leading to the development of adequate coping skills. The widely used assessment tools that are helpful in providing insight into language disorders and aid in identifying their presence are Peabody Picture Vocabulary Test-4 (PPVT-4) and Expressive Vocabulary Test-2 (EVT-2). These tests evaluate comprehension of spoken English and measure a person's achievement in acquiring vocabulary and can thus be used to detect language impairments at all ages.