A doctor from India when he was 18 and again when he was 24 experienced extreme adverse states from meditation practice.
I am a doctor. When I was in college days due to stress, which comes with medical studies, I decided to go for the stress reduction technique of meditation. I am a happy positive and cheerful person usually in a jolly mood. After a few days I found that I was becoming silent; like a dull brainless zombie. I thought I was developing calmness but gradually it was like that every sense was defective. I had severe depression, hallucinations, panic attacks and I heard voices in my ears constantly. I just wanted to be alone at home not speaking to anyone, silent like a ghost. I even broke a precious relationship in this state. Then I went to a psychiatrist. After six months of treatment I was fine and back on track. I never understood what was the problem. Now after starting my own clinical practice and due to workload stress I decided to practise meditation again to reduce stress at the end of the day and all of sudden after one month the same problems arose. I was shocked. I am actually an unbreakable kind of person but with this feeling of something very tormenting I joined the dots and realised that for me it was caused by meditation practice.