Anxiety is not single disorder. It is a spectrum with varied presentations. It is not caused by virus, bacteria or fungus to be get rid off or cured. It is a disturbance in the internal milieu in an individual, more specifically the pathways of the mind determined by biological, psychological and sociological factors. For some anxiety disorders are short lived and disappear spontaneously too, for some with treatment the symptoms remit in few months, for some some it carries on lifetime too. But with effective treatment as long it is present, treatment can keep the symptoms under remission.

It's purely depends on individual. It's based symptoms severity and how medications are been used and regular follow ups.

Yes, many of my patients are doing well after stopping treatment, duration varies from individual to individual, there are many who need continuous treatment