Reviews on some psycho pathological horror movies

I do not understand why such horror movies and psycho analytic movies were made so often. Maybe because they attract interests of people. Or, any normal person might have some of such pathological experiences or people sometimes imagine such horrible things in their heads. Or they can be influenced by such things, though not all of them might put them into practice..Human beings have such mental aspects, and they wonder what if they cross the line of normality from time to time. Getting mad and losing their minds...
This might be the reason why such psycological and pathological movies have been often made. Also, many people seem to be in agony and distress on account of loneliness, outer appearances, relationships with other people, fierce competition to be famous and successful...maybe