Major depression is a serious and persistent condition that leaves a person with unshakeable feelings of sadness or hopelessness and permeates many different aspects of his or her life. While each patient's condition is unique, some of the more common symptoms of major depression include a lack of interest in once-enjoyable activities, unexplained fatigue, increased irritability, feelings of worthlessness, changes in appetite, sleeping difficulties, and thoughts of suicide.
While major depression has been extensively studied, researchers are still unable to pinpoint a specific cause for its occurrence. However, there are several potential factors that may play a role in the development of the condition. Here is a look at some of the most widely accepted possible causes.
Biological Factors
There is some research to indicate that physical changes in the brain are associated with major depression. For example, the hippocampus, amygdala, and prefrontal cortex—three areas of the brain responsible for the management of stress and other emotions—appear to shrink in patients with major depression.
Brain Chemistry Factors
Neurotransmitters are special chemicals within the brain that used to help the organ communicate with itself and with the nervous system. When these chemicals are out of balance it's possible for major depression to occur. However, as of now it's impossible to measure specific levels of neurotransmitters within a patient's brain, so the exact role they play in the condition is still unknown.
Hormonal Factors
Menopause, premenstrual syndrome, thyroid problems, and other conditions that change the balance of hormones in the body may be responsible for the development of major depression. However, in cases like these, fixing the underlying problem may help alleviate or even eliminate the major depressive symptoms.
Genetic or Inherited Factors
Scientists are also currently looking for genetic traits that may contribute to the causes of major depression. If a person's family members have had problems with depression in the past, he or she has a higher risk of developing the condition as well. Researchers continue to look for the specific genes that may help enable the spread of major depression across generational lines.
Life Factors
Dealing with a stressful life situation may cause major depression or intensify the condition if it is already present. Events such as the death of a loved one, a job loss, or the development of an illness may trigger depression. In some cases, the situation may change for the better, which allows the condition to pass. However, if a person doesn’t deal with the cause of stress, major depression can set in.
