Loneliness is generally cause by a lack of connection and intimacy with other people. Connection and intimacy is necessary for all humans; it is the way we are made. Loneliness has significant negative effect on the brain. Loneliness has a physiological reality, and does not only exist because someone "thinks" they are lonely.Thoughts alone will not change the reality of loneliness. Only creating connection and intimacy with others will. Of course, this is difficult for many.May I reiterate- WE ARE NOT MEANT TO EXIST ALONE AS ISOLATED INDIVIDUALS; we need each other. Lying to ourselves that we don't need anyone else makes the situation worse, for it will often lead us to emotionally isolating ourselves more and to putting up more walls between ourselves and others, taking us even further away from the solution.Loneliness is a symptom of a real problem.