Can an adult with a diagnosis of a mental health disorder refuse doctor orders? Why or why not?

This individual has a dual diagnosis of General anxiety disorder and an Eating disorder. Does that person have any rights? This person isn't severely affected nor in danger of thier self or others.

: http://alcoholdrugstreatment.info/can-an-adult-with-a-diagnosis-of-a-mental-health-disorder-refuse-doctor-orders-why-or-why-not