Chris Prentiss said this quote

Depression can be due to a low endocrine function, nutritional deficiencies, blood sugar problems, food allergies, or systemic yeast infection. Depression can also result from medical illnesses such as stroke, heart attack, cancer, Parkinson's disease, and hormonal disorder. It can also be caused by a serious loss, a difficult relationship, a financial problem, or any stressful, unwelcome life change.