After 3 months of citalopram therapy, S.K. reports she has had no panic attacks in the past month...

After 3 months of citalopram therapy, S.K. reports she has had no panic attacks in the past month and her functioning has improved dramatically. She is currently taking 40 mg/day of citalopram and gradually stopped taking the alprazolam 3 to 4 weeks ago. S.K. reveals she is painting regularly, selling some of her paintings, and paying her rent, and she has begun dating again. S.K. is experiencing no significant side effects from citalopram except for some sexual dysfunction. She wonders how long she should continue taking it since she is doing so well. What is the recommended duration of treatment for panic disorder?