This is a reasonable question and difficult to predict. Research shows that the duration of therapy is variable and can be influenced by the therapeutic approach, the strength of the relationship with your therapist, and factors specific to you. These other factors may include your goals; personal characteristics; the nature, severity, chronicity, and complexity of the problems you are experiencing; external factors such as what else is happening in your life and available social support; the extent to which you actively engage in the treatment; and how comfortable you are with making changes.
Depending on your specific needs and goals, therapy can be short-term, for a specific issue, or longer-term, to deal with recurrent life patterns or more in-depth personal growth. Therapy is a collaborative process, and your progress and goals will be discussed throughout the course of treatment.