My mother in law has been on levothyroxine for 26 years and decided to quit taking it in May without telling anyone. I guess she was tired of being unable to lose weight and has been trying to give her life a whollistic makeover of a sort. Four months went by without notable side effects (meaning, I didn't notice anything), but then she suddenly seems to have had a psychotic episode that has been ongoing for over a week now. She's not eating or sleeping and has had to be under the constant supervision of her husband so she won't hurt herself or run away on foot. She is having premonitions where she thinks she's going to die or that something terrible has happened to a family member, and she is absolutely hysterical. Her husband took her to the ER and they gave her a potassium IV, and he also started forcing her to take the meds she quit taking at the onset of the episode; it's been 8 days without improvement. I am really scared. The doctors don't seem to be as concerned as they should be, and the correspondence with the meds discontinuation is not what I'd expect. Like I said, four months before being off the meds to start affecting behavior, then 8 whole days back on without any improvement.