Intensity of aphasia therapy: evidence and efficacy.

Determining the optimal amount and intensity of treatment is essential to the design and implementation of any treatment program for aphasia. A growing body of evidence, both behavioral and biological, suggests that intensive therapy positively impacts outcomes. We update a systematic review of treatment studies that directly compares conditions of higher and lower intensity treatment for aphasia. We identify five studies published since 2006, review them for methodologic quality, and synthesize their findings with previous ones. For both acute and chronic aphasia, results at the language impairment and communication activity/participation levels tend to be more equivocal than previously demonstrated, with no clear differences between intensive and nonintensive treatment emerging across studies. Future research directions are discussed including research design, definitions of treatment intensity, and behavioral and biological measurement of short- and long-term changes following implementation of an intensive treatment.