How intensive/prolonged should an intensive/prolonged treatment be?

Background: The issue of efficacy of aphasia therapy has long been debated and there is now convincing evidence that treatment is effective. More focused questions on aphasia therapy have also been addressed, although less frequently. This paper reviews the literature on the effect of intensity and duration of treatment. Aims: Data in the literature on intensity and duration of treatment are reviewed. Main contribution: Positive and negative studies on treated and untreated patients are reconsidered and the length of treatments in the two groups is compared. Studies directly tackling the question of intensity/duration of therapy are briefly reported as well as the results of a meta-analysis. Improvement in three pairs of matched subjects, all treated for very long periods of time but with different intensity, is compared. Conclusions: Results clearly indicate that the number of therapy sessions is an important factor in recovery. Results of the meta-analysis support this conclusion. There are also indications that when therapy is protracted for many months or even years with a very strict regimen (2-4 hours daily), aphasic subjects show clear improvement in their daily use of language and communicative competence.