My sister has been on anti-depressants for 20 yrs due to severe clinical depression which she developed in her 20s accompanied by OCD. In the 20 years in between she has always been slightly depressed but ok. Last year she started drinking very very heavily almost as an alcoholic and started to forget to take her anti-depressant tablets that she's been on since that episode in her 20s, and slowly her behaviour became a bit euphoric, but when the doctor stopped her anti-depressants abruptly when she developed Pneumonia as they interacted with the anti-biotics, she suffered severe problems within 2 days of stopping them, including delusions and this was then followed by mild mania for 10 mths. It has taken until 3 months ago to decide she may have Bipolar and she has been tried on various meds. This week she has dropped from high to deep depression after they changed her tabs again. I want to ask, could it be that she had Bipolar since the first severe depression in her 20s but it has been controlled by the anti-depressants so never picked up on. Or is it that stopping the anti-depressants so suddenly triggered the Bipolar? No one else in the family has it, but my other sister has unipolar depression recently. Also, the sister with the ?Bipolar has 2 children, is it very likely that they will also develop the condition and if so, would it be in adolescence or when they are older? And is it also possible that my other sister with unipolar depression might turn into Bipolar, or if she was going to develop Bipolar would it have happened in her 20s, if this is what you think happened to my sister who has now been diagnosed with the ?Bipolar. Her doctor thinks it's just normal depression but she is worried. Sorry this is so long.