This form of depression can occur from not knowing how to deal with life on an adult level, experiencing temporary set backs, or dealing with manipulative or pushy persons who leave one feeling helpless, unworthy and frustrated.General depression should be taken seriously and steps should be taken for healing to prevent further emotional distress.
There is also a clinical depression which is a serious medical illness that negatively affects how a person feels, their thought process, and their physical and mental functioning regarding daily life. For instance, clinicaldepression affects the body, moods, thoughts and behavior. It can change eating habits and dictate how one interacts with other people, including family. People with depression either state that they don't feel like themselves any longer, or they will say there is nothing good about life in general and they can all but give up on life enjoyment.
However, from the many situations I've witnessed, when some people only receive medical treatment, they tend to continue with medication therapies prescribed and counseling sessions without experiencing healing.
You probably think you're doing everything you can to stay healthy: you get lots of sleep, exercise regularly and try to avoid fried foods. But you may be forgetting one important thing. Relax! Stress has a bigger impact on your health than you might realize.