Approximately what percentage of clients may worsen during the course of therapy?

• A. 0%
• B. 20 to 30%
• C. 5 to 10%
• D. 40 to 50%

Answer: (C)

In psychotherapy, it’s recognized that a small minority of clients may experience worsening of symptoms or functioning during treatment, even though overall outcomes are generally positive. This deterioration is a real but relatively rare risk, and most clients improve or stabilize. The best estimate is that about 5 to 10% of clients may worsen at some point during therapy, reflecting factors such as emotional overwhelm, a mismatch between the intervention and the client’s needs, diagnostic complexity, or issues in the therapeutic alliance.

Understanding this helps emphasize why ongoing progress monitoring and supervision are important, so any signs of deterioration can be addressed promptly. The other options imply no risk or an unrealistically large risk, which isn’t consistent with the observed range in psychotherapy research.