Depression can be quite debilitating. I have gone through difficult periods and know from personal experience that even mild symptoms of depression can ruin one's life.
Here are some common symptoms: inability to sleep, inability to concentrate, decreased sex drive, feelings of hopelessness, negative thoughts that you can't control or just will not go away, lack of appetite or excessive binging, and a lack of self-esteem.
This last one is particularly important. As human potential coach Brian Tracy once put it, self-esteem is not our self-concept. It is not in idea about ourselves. It is the feelings that we have about our own selves. Do we feel that we are valuable, do we feel successful, or do we feel that we are complete failures?
The first thing you have to do is change your thinking. Many people trip themselves up by the definitions they attach to certain words. For example, how do you define success? If your mind comes up with some unattainable image of a Hollywood-style mansion and a bunch of objects or achievements you must have in order to feel successful, then you have sabotaged yourself. So the first thing you must do is to define happiness in simple terms. You have to do this for yourself, you can't wait for society to give you the answers. Externally-imposed answers can never be what you truly want.
The second thing you have to do is change your lifestyle. If you spend a lot of time alone, then start spending time with other people. It doesn't matter exactly how you do it, the important thing is that you do it and that you force yourself to do it. Call old friends, go to Starbucks and talk to a stranger, anything to change your habit of being alone. If you spend a lot of time in the city, go on a hiking trip, sign-up to a mountaineering club, go to a park.
The third thing you must know is that exercise has been proven to be more effective than pharmaceutical drugs at improving and alleviating the symptoms of depression. Any type of exercise will do. If you have no time, then do a 20 minute workout in your home. Run up and down the stairs a few times. Do whatever your body can handle and never do it in excess. The chemical cascade that will result in your body will make you feel better.
The fourth point is to change your diet and take concentrated fish oil supplements every day. In cases of depression, simple sugars and refined carbohydrates are your biggest enemy. You should stop eating white bread, white rice, white flour, sugar and sweets and even sweet fruits. You should restrict yourself to brown rice, brown bread and sour fruits, such as Granny Smith apples, Kiwis and grapefruits. Also, it is very important to eat enough cholesterol, as cholesterol is what your body needs to make the hormones than deal with stress.
As far as supplements go, there is nothing better that y you can do for yourself than to take molecularly-distilled concentrated fish oil capsules every day, at a dose of a minimum of six capsules a day. Concentrated fish oil contains DHA. DHA is one of the most important substances in the brain. Research has shown very consistently that an increase in DHA consumption can help eliminate or at least alleviate depression.
Make sure that you buy a pure, top-quality concentrated fish oil by a reputable manufacturer, made with fish from clean, uncontaminated seas, such as those off the south coast of New Zealand. It should be accompanied by an independent certificate of analysis proving that the product is clean, safe and effective.