Sudden change in behaviour

My Brother has had a sudden change in behaviour
Family background
He is Weed and alcohol addicted and brother of two schizophrenic siblings

He has spent 6 yrs isolated completely living at my Dads house
Self harm in extreme
Low level psychosis
Anxiety disorder
Drinking in a darkened room
major depression
Unstable personality disorder
Huge very significant PTSD from age 3

He is suddenly changed over the last 1 - 2 weeks
He has been talking about being " schizophrenically paranoid
For the first time ever that she said “maybe id be better off in a mental hospital with forced medication”
Said once to me…
He is paranoid to buy alcohol
He spoke about wanting to leave the south west Region and not go anywhere hes been before

Main real change though in his behaviour
He met a friend who she has hated for 2yrs
She has been in and out of my place without speaking and picking up abd dropping off a spade… spending time where our brother was killed by a car
Getting lost frequently in a local wilderness area
Going out at 5am and driving 80 miles and returned at 9.15
Forceful with everything hes doing and not talking about what he is doing

I’m so sorry this was happening to him. It is so hard to watch someone acting ill and to not be able to help them.

https://www.mayoclinic.org/tests-procedures/electroconvulsive-therapy/about/pac-20393894