There are very many physical causes of Depression I this worlds today and they are scattered everywhere in our daily lives such that it is very hard to avoid them .Some of this causes are just our fellow human beings whom you can not live without talking to so that you can get what you need in order to live your own life .So, it depends on ones actions towards the other people who are I his or her environment.
If you are strict and hostile in every thing that you do, you don't expect people to be soft with you when you mix and do things together .But if you are a friendly person, mixing and doing things with other people will be very easy for you.
So, depression mostly happens to us when we are beaten and are completely helpless before the powers of nature in our lives .Take an example of someone who just finished school .He or she doesn't the power for deciding for this world what to do ,and perhaps she can not be understood what she or he wants this world to view him like ,and the this person lives up to forty years old without employment or without any source of income in their lives ,the person will start losing hope slowly by slowly as they continue becoming helpless before the forces of nature that bring about livelihood or the basic needs in their lives .This person continues losing hope until it becomes very severe and deep rooted in his mind and emotions that no causes of happiness can make them happy enough to bring back their spirits to the levels that they are expected to reach and they remain depressed that way for the rest of their lives .
Another cause of depression is when parents in the home can not realize that their children have grown up and that they are now men and women a who can contribute in the matters that concern the family .Their reasoning capacity is now equivalent to that of a normal mature human being and therefore when they pass decisions in the family ,especially in matters that involve their children ,they have to be careful how hey do it ,not to dictate the family without a proper cause .They have to talk to their children with dignity so that they feel that they are valuable despite the various weaknesses that might be in them ,say perhaps they eat a lot or are their bodies are not well structured to enable them to do well in things like sports and the others or they might not be very good at school work ,but with living life every human being can and every human being knows what is right and what is wrong .So ,you've got to be careful ,perhaps you might be talking to a man and not a child any more..
Continuing bulldozing a twenty years old man in the name of disciplining him does not help him any more at that age ,instead ,it worsens their emotional problems which later develops In to depression and other psychological complications which if not taken care of early enough ,will even change their lives from what school molded them in to and they will start seeing life and nature in general differently .They will start seeing themselves as useless things in life and life will reduce in value before them and perhaps they will remain this in their inside for all their lifetime .It is very hard to find some one who can disclose this to their parents or someone who can listen to you sincerely if it happens that it is you who is in the trap.
So, instead of calling for a meeting of elders in your house because your son has pinpointed your mistakes in the house, just go and check yourself and mend and change your behaviors to fit with the new environment in the home .Loss of hope and value before our own parents makes us to lack asylum from the harshness of the real truth in live of this world which then develops in to depression due to the lack of the chances to get what we can replace the depression with.
Some people do make mistakes and then they slide backwards in life .Perhaps they lose their jobs for good before they accomplish some of the things that they had targeted in their lives or sometimes others do loose all their wealth ,perhaps what they had gathered for a period of twenty or thirty years .Such people will have problems in mixing with the people who had been below them in life .They will be feeling ashamed for lacking the things they used to have before they fell and for serving the same people who used to be their own servants inside their homes .So such cases ,if they are not taken care of early enough ,will develop in to depression because ,for such people ,it will be very hard to get any lively hood unless they will be able to know how to live their new lives and in their new environments.
Continuous humiliation and misuse of power against us at places of work ,in the public offices and other public facilities and the rest .The people who are in power in those places do sometimes do this things to us and leave us with internal harm .After such incidents ,some people are left with changed thoughts towards life .They feel that they have been beaten and that there is no alternative for them because the world has been totally sealed out for them by those who are and they have no hope of ever making it again through those places and they loose hope and depression slowly takes the place of livelihood in their lives.
So, depression mainly comes in to our lives after we have been beaten to accomplish some of the things that determine, perhaps the future of our lives or the modes of living our lives and then the whole world looks like it has denied us forever and is sealed completely to us such that we can not reach the things that we would need for living our kinds of lives that we had targeted.