Characteristics of Developmental Language Disorder in Adults: A Scoping Review.

Purpose

This scoping review aimed to map existing research on characteristics of developmental language disorder (DLD) in adults and describe this body of research. Furthermore, assessment practices used to identify adults with DLD in the included studies were investigated.

Method

A broad search was conducted across three international research databases to identify all peer-reviewed studies on DLD in adults from 1990 onward. The identified studies were collated and presented through numeric and thematic analyses. The numeric analysis comprised the categories publication period, location and language, research groups, main topic, and DLD terminology. The thematic analysis covered group identification, characteristics of language ability, domain-specific and domain-general cognitive characteristics, and biological characteristics.

Results

Though the search was inclusive and spanned 35 years, only 53 studies were identified. Results supported that DLD persists in adulthood and is associated with difficulties in language ability, as well as cognitive and biological characteristics, often recognizable from child studies. There are concerns related to diversity and geographical spread in the research community. Research output over time is modest.

Conclusion

There is considerable heterogeneity in the research base, making it difficult to draw firm and specific conclusions, illustrating a clear need for further research on DLD in adults.