Even though the head injury was a long time ago, sometimes it can take a while for symptoms to show up. I have known multiple people who have gone a year or more after a TBI "doing fine" and then started having major personality changes after that time. This is not to say that his symptoms are DEFINITELY caused by his head injury; there is certainly the possibility that he has a concurrent psychiatric diagnosis. His symptoms sound consistent with a diagnosis of bipolar disorder, but I wouldn't want to diagnose this without further testing of brain functioning related to his injury.
i do believe it something like bipolar i have done some research, but i think the doctors are swayed by the fact he has miss used drugs and alcohol not often but he has taken some. i just dont seem to be gettin my views heard here in northern ireland and i would hate to think they could miss diagnose sorry to reply again i just need to know someone listening to me. thankyou