Mice and men .What roles do psychological disorders and dreams play?PLEASE I NEED AN ANSWER TILL TOMORROW

I don't think there is a lot about psychological disorder in the book. Lennie is mentally challenged; he doesn't have a disorder. Lennie's imaginings of the big rabbit and Aunt Clara at the end of the book are manifestations of the intense stress he is feeling: Lennie know something has gone very wrong and he, with his limited intelligence, is trying to process it the only way he can.