Is it possible to measure psychotherapeutic change retrospectively?
Traditionally, at least two measurements — before and after therapy — are required to measure therapeutic change. But is it possible to capture change with a single retrospective measurement — that is, by directly asking a client about the magnitude of perceived change? We have found that a questionnaire based on this approach measures change in a similar way to traditional pre-post measures. It has the advantage of being more sensitive to change and easier to implement in practice. The disadvantage is clients' tendency to overestimate the magnitude of change compared to traditional pre-post measurement.