Many people come to therapy to try to reduce the severity of their psychological symptoms, and this article summarizes research on symptom reduction. However, it is important to understand that while symptom reduction is important, it is not the only measure of success in psychotherapy. See the following article for a discussion of complex change in psychotherapy: What is Mental Health?
HOW MANY SESSIONS ARE NEEDED TO PRODUCE MEANINGFUL CHANGE?
Studies show that the more psychotherapy one gets, the greater the probability of improvement. Howard, Kopta, Krause, & Orlinsky (1986) showed that 53% of clients showed clinically significant symptom reduction after 8 weekly sessions, 75% by 26 sessions, and 83% by 52 sessions. Anderson & Lambert (2001) examined less severe cases and found clinically significant improvement to be quicker, with 50% of patients improving after 7 sessions of psychotherapy and 75% improving after 14 sessions.
By how much can one expect to improve over time?
Anderson & Lambert (2001) and Hansen & Lambert (2003) used statistical methods to model the number of sessions needed for patients to return to a normal state of functioning (i.e., to have no more symptoms than people in the general population). They found that about 33% of patients recovered by the 10th session, 50% by the 20th session, and 75% by the 55th session.
How long should a client continue with psychotherapy?
This depends on a number of factors. Some disorders yield more quickly to treatment than others (Lambert et al., 2006). Client age also appears to be relevant; adolescents typically have better treatment outcomes than adults or younger children, but studies have shown that treatment may take longer to achieve these outcomes with teens. Response rates also differ based on treatment goals (Maling, Gurtman, & Howard, 1995). It is always best for clients to make treatment decisions in collaboration with their therapist.