Loneliness, anxiety & depression are extremely complex emotional and spiritual issues. They are very complex for many reasons and one such reason is that there are diverse opinions as to the cause or causes and its cure or remedy. Everyone seems to have an opinion as to its origin and cure if there is such a thing as a cure! If you were to consult a Psychiatrist, you may hear one thing and if go across town and consult a Psychologist, you may hear something completely contrary. The simple truth is that emotional issues are universal human issues and everyone deals with them on a daily basis but very few are experts in emotional issues. Emotional issues can simply be addressed in three ways and in these three ways, we would address causation and remedy and here are they: Medical, Psychological or Spiritual: 

1. Emotional Issues are Medical Issues: The believe that loneliness, anxiety, depression and a host of other emotional emotional are medical issues is deeply rooted in our society. Psychiatrists are medical doctors trained to diagnose and treat emotional issues. In the mind of a Psychiatrist, the cause is most likely some chemical imbalance and some medicine would be the appropriate remedy. 
2. Emotional Issues are Psychological Issues: A psychologist on the other hand would approach these issues completely different: They would assume that these emotional issues have been caused by your family of origin background, family status, upbringing. Your environment has influenced your emotions. They would provide several solution like, “Talk therapy,” where you are  counseled through the things that are causing your sense of loneliness, anxiety and depression. In terms loneliness, they may advice to get out and make friends and create a social network or offer “cognitive behavior therapy,” CBT where they try to talk you through some behavior modification. 
3. Emotional Issues are Spiritual Issues: Most people including Pastors would hardly treat emotional issues as spiritual issues. Any help from a Psychologist or Psychiatrist to remedy any form of emotional issues is short lived. The very first time that a word dealing with emotion was used was in the Bible. Genesis 2:18 says , It is not good for man to be alone.” So the idea of human companionship is engraved in the human DNA. In Psalms 25:16 it talks about a lonely heart. There is clear distinction about being alone and being lonely. Loneliness is more that having companionship. Loneliness is a soul void of the presence of and companionship with God and aloneness is companionship with fellow humanity. These are distinct. very differnt.