The manic cycles can seriously affect thinking, judgment, and social behavior. The alteration of the cycles of depression and mania are always quite dramatic and can be either gradual or rapid. It can be quite severe and it is the result of serious hormonal imbalances in a women after childbirth. It is often accompanied by a decrease in energy, an increased need for sleep and carbohydrate craving. Phototherapy for SAD has been proven to be quite helpful.
People are susceptible to depression for many reasons.
Depression seems to be caused by a combination of environmental as well as chemical factors. This evidence suggests that people surrounded by serious stress may be more susceptible to depression than people with less stress in their lives. Separation and the loss of a loved one seem to be serious stressors that often lead to depression. The fact that separation and loss of a loved one can be a serious cause of stress makes me wonder about peopleUs necessity for other people and their necessity for love, companionship, and affection. I know their have been many studies on people that have shown correlations between the amount of love and affection people receive and their development and ability to function.