In an unusual diagnosis, doctors have described a 23-year-old man in Turkey as suffering from "vampirism" after he was caught several times trying to stab people and drink their blood, according to a report.
The man became addicted to drinking human blood after he started slicing his own arms, chest and stomach with razor blades, and gathering the blood in a cup so he could drink it, doctors say.
He soon became addicted and started turning to other sources to feed his habit which he described as being "as urgent as breathing", the 'Daily Mail' reported.
He apparently even got his father to get him bags of the bodily fluid from blood banks, according to the report published in the Journal of Psychotherapy and Psychosomatics.
The man, whose name was not revealed, was arrested several times after stabbing and biting others to collect and drink their blood.
He also developed multiple personalities and suffered from amnesia.
"Possibly due to 'switching' to another personality state, he was losing track during the 'bloody' events, did not care who the victim was anymore and remained amnesic to this part of his act," the report said.
"Medical professionals believed his behaviour was a reaction to horrific events in his life, such as witnessing a killing where one of his friends cut off the victim's head and penis," the researchers said.
He had also been traumatised by the death of his four-month-old daughter, and by the murder of his uncle.
Doctors, led by Direnc Sakarya, of Denizli Military Hospital in southwestern Turkey, diagnosed the man with dissociative identity disorder (DID), post-traumatic stress disorder (PTSD), and chronic depression and alcohol abuse.
To their knowledge, the man is the first patient with 'vampirism' and DID.
Researchers note that DID is often linked to childhood abuse and neglect. The blood addict's mother was described as having attacked him in 'freak out' episodes during his teenage years, but the man said he had no memory of his childhood between the ages of five and 11.
The man felt tortured by an 'imaginary companion' who forced him to carry out violent acts and attempt suicide.
In a follow-up six weeks after he was treated, the doctors said the man's blood-drinking habits were in remission, but his dissociative symptoms persisted.
The man did not experience any negative physical effects from his gruesome habit, but the human body is not well adapted for digesting blood.
While small quantities may be harmless, anyone who consumes blood often runs a risk of haemochromatosis --an iron overdose - or contracting blood-borne diseases such as HIV if blood is sourced from other people.