Hai agent001ck ,
In this case sailient findings are
accident 11 years ago with residual disability
prescence of mood disorder
Kindly uderstand if your friend had brain damage
and dysfunction following that that too remaining for about 11 years then he need to go for Neuro Psychlogical Assesment .following which he will be given some excersice which will gradually make him better than now.
Also in this case memory disturbance may be due to Psedodementia because of underlying depression
. If so by treating Depression his memory disturbance will vanish.
So i suggest you to Meet a nearest psychiatrist
to evalute your Memory disturbance . Also ask for NeuroPsychological asesment to diagnose also for prognosis.
I wish him to get better Physically and mentally