I see most people with PTSD for 10-20 sessions. Within 10 sessions, clients generally have a sense of whether treatment is working for them.
Many people have experienced multiple traumas–sometimes so many that they blur together. In these instances, treatment may be effective but the course is more complicated. However, people still have a sense whether we are on the right track within 10 sessions or so.
In sum, many people find relief for their pain in as little as 3-4 months. For others, the road to recovery may be longer and more windy. I don’t expect anyone to be in treatment with me for months without any noticeable improvement, and I am always adjusting throughout treatment based my approach on what is and is not working.