Is this also part of ADHD? ...

hi ... I have a situation a home right now that I have no idea if it is ADHD or just some paranoid situation ...

My partner was not diagnosed as a child and by the age of 18 he was diagnosed as schizophrenic ... now it is a mix of schizophrenia with ADHD ... since I am here I notice that sometimes he gets super stress if he misplace some items like his mobile or his wallet ... I try to keep an eye on where he left his stuff and when comes and ask where they are, I let him know .. of course it works when I see it ... but not when I don't see where he place them. 

Like one month ago he brought a tablet from his brother ... he couldn't use it and put it in a bag ... in the meantime, i forgot to close the window and he forgot to close the balcony (we live in a first floor apartment) ... long story short: he can't find his keys now, he can't find his tablet now .. and now has the idea that someone enter the apartment and steal those specific items despite I have my laptop almost in the same place where he "left" the tablet and also there is the TC screen ... he gets angry if I don't agree with him that someone enter the apartment and he says that he already searched in his whole room (he previously said that and later find things) ... after 9 months of the same .. I just let him be .. he complains and screams and get frustrated and when i try to say something and is not what he expects ... I am the wrong one and the no supportive one .. 

What is this situation about? I am aware he misplaces his items but now saying that someone enters the apartment and steal specific items that he can't find and then accuse me of ignoring him, that it doesnt matter to me or not being supportive is part of the ADHD or is just paranoia?