Information: Serious Mental Illnesses
The usual ones are:-
These are characterised by strange experiences and thinking, like seeing or hearing or smelling things. Strange thoughts can include believing that you are in danger from unusual things, like aliens, or from people who you do not know.
Other illnesses in this section, can be serious if severe, but thinking and expereinces are usually normal.
Having unusual experiences, does not mean you have one of these illnesses, they can be caused by tiredness or stress or illegal drugs.