The friend described how 24-year-old Winehouse's convulsions were so bad that they were "like a scene from The Exorcist", and as her body had become frail from the drugs, doctors were scared her bones would break during a fit.
The first overdose had taken place in August last year, and it had been brought about by the singer's use of cocaine, heroin, ecstasy, ketamine and crystal meth.
The Rehab singer was advised to see a after displaying "multiple personality traits" that could drive her to commit suicide.
Her second overdose in July was caused when she inhaled an "inhuman" amount of hash, which left her vomiting uncontrollably and hallucinating.
At the time, her devoted dad Mitch, 54, said that it was a "bad reaction to her medication".
"The future is bleak, bleak, bleak," the Sun quoted a friend of hers as saying.
"Mitch does everything he can to protect his daughter - but his 'explanation' for Amy's hospital dash in July was just simply untrue.
"She had smoked an inhuman amount of hash which resulted in acute cannabis poisoning. You have to take a s***load of pot to suffer that severe a reaction.
"It's thought she had been smoking it for 36 hours.
"Amy's fits were as bad as the convulsions she had during her overdose in August last year. No one has mentioned her meth use before - but that stuff is truly nasty.
"She is in need of years of psychiatry and medical treatment if she has a hope," she added.