How do i know if i should seek help for my depression?

Feeling Good: There are several types of depression. Reactive depression occurs as a result of loss and eventually we adjust. If one does not adjust or if the cause is not clear certainly seek professional help. "feeling good" by david burns is an excellent self-help book based on science. Don't let the thickness of it intimidate you. Take it bit by bit. The very best to you.

A good rule of thumb: is that if it's interfering with your social life or your work, then it probably needs to be addressed, regardless of the "why's or whens" about it. Most people can point to situations that cause their depression, however when it interferes with their functioning in a meaningful way, it warrants treatment for preventative reasons. How much interference in those areas of life is entirely up to you.