Doctors believe a traumatic brain injury gave rise to obsessive–compulsive disorder in a young man who began hoarding deodorant and completing tasks in a “ritualistic manner” after a long stay in hospital. 

The team, from the University of Calgary in Canada, said their patient had sustained serious injuries in a car accident during his late adolescence. 

The teenager had undergone an emergency craniotomy to evacuate a large, left-sided subdural haematoma, after which he remained in the ICU in an induced coma for three weeks. 

After waking, he spent a month in the neurosurgical unit and two months in the neurorehabilitation unit before discharge to the care of his family, the doctors write in BMJ Case Reports.