This paper aims to critically review current studies with respect to definitions, methods, and results on the comprehension of metaphor, metonymy, idioms, and proverbs under the following clinical conditions: aphasia, Alzheimer’s disease, autism, brain injuries, specific language impairment, and Williams Syndrome. A comprehensive search of experimental psycholinguistic research was conducted using EBSCOhost, PsychInfo, PUBMED, and Web of Science databases. Thirty-eight studies met the review inclusion criteria. Results point to deficits in figurative language comprehension in all conditions considered, lack of clear definitions of the phenomena investigated, and varied methods throughout the sample. Patients’ difficulties are attributed to multiple factors, such as a lack of Theory of Mind, executive dysfunctions, and poor semantic knowledge. The study of nonliteral aspects of language comprehension in clinical populations reveals a range of disparate impairments. There was no specific feature about metaphor-related phenomena identified that could, on its own, account for the difficulty some populations have to understand figurative language. Rather, metaphor-related language comprehension difficulties are often part of pragmatic, linguistic, and/or cognitive impairments
