Because every therapy is highly individualized, the length of the therapy varies from person to person.
How long it takes to see improvement varies with the problem. The more specific the problem, the faster one will experience symptom-relief. Treatment of panic, phobias, specific relational conflicts is relatively short-term. Significant improvement can be seen within 8 to 16 weeks and sometimes quicker than that. The problems that are more global and diffuse take longer to subside. These are the general patterns that represent one’s habitual ways of dealing with the world at large, behaviors that are part of one’s personality/character. These are more intractable and may need a long time to part with.

People are often invested in their habitual ways of being, thinking, and feeling. Sometimes people feel like they are asked to give up their old friends when therapists highlight these defensive, self-defeating patterns. There is safety in the familiar, even when it is really harmful for us. Becoming aware and changing these maladaptive habits is a journey that takes time. How much time depends on how motivated and willing the person is to apply oneself to the often arduous and emotionally draining but in the end rewarding work of psychotherapy.