Major depression seriously affects a person's ability to work, sleep, deal with the family or enjoy life in general. Bipolar disorder is another form of depression in which mood changes can cause a person to have extreme highs and lows in behavior. Postpartum depression can occur to some women after birth. Seasonal affective disorder, also known as SAD, can depress some people during certain times of the year. Some people may feel depressed at times, but serious depressive symptoms may last for two or more weeks.
Emotions
There may be persistent feelings of sadness or emptiness in a person's mood. The changes in moods may bring about a lack of interest in normal daily activities or in activities once enjoyed. Feelings of hopelessness or worthlessness may also be present. There may even be periods of crying spells for no apparent reason, according to the Mayo Clinic.
Behavior
People who are becoming depressed may suffer from sleeping difficulties. They may be easily annoyed and experience signs of irritability and restlessness. It may be difficult for the person to focus or concentrate on tasks or everyday activities. There may be a loss of pleasure or interest in sex.
Physical Changes
Depression may lead to feelings of fatigue or weakness. Unintentional weight gain or loss may be noticed. Depression may also cause vague complaints of physical problems that include back pain or headaches. Digestive disorders may also accompany depression. Some people in the early stages of depression may even go to a doctor with physical complaints that cannot be diagnosed or improved with treatment. Thoughts of suicide or death may haunt the person at times.
Co-existing Illnesses
Anxiety disorders, panic attacks and social phobias may occur before or after depression is suspected. Post-traumatic stress disorder may lead to depression. This happens following traumatic experiences that may include assault, accidents, family tragedies or other terrifying events. Alcohol and substance abuse may occur with depression, according to the National Institute of Mental Health (NIMH). Depression may also be brought on because of medical illnesses such as heart disease, stroke and cancer. Physical illnesses may cause more-severe symptoms of depression and lead to worse physical symptoms of the illness. The NIMH points out that 40 percent of people with post-traumatic stress develop depression a month or a few months later.
Varying Symptoms
Not everyone experiences the same symptoms. People may experience different symptoms at different times. The Mayo Clinic advises that if you have five or more depressive symptoms that last for two weeks or longer, you may have a serious depression problem and should seek help.
