According to the National Institutes of Health (NIH), "Clinical depression is a mood disorder where the feelings of sadness, loss, anger or frustration interfere with everyday life for an extended period of time." The clinical symptoms of depression range from mild to severe, and can affect the patient's quality of life. The type of depression that the patient is diagnosed with depends on the symptoms displayed, according to Dr. Daniel K. Hall-Flavin of the Mayo Clinic. For example, a patient who has five or more symptoms of depression are diagnosed with major depression.
Sadness
Sadness is the hallmark symptom of depression, according to the NIH. However, clinical depression is different from feeling sad every once in a while. The patient may also have feelings of hopelessness or helplessness with the sadness. In addition, she may feel worthless, hate herself or have inappropriate guilt. The sadness from clinical depression can escalate into thoughts of death and suicide, and even suicide attempts. Any thoughts of suicide that the patient displays should not be ignored.
Concentration Problems
Concentration can also be affected by depression. According to the NIH, patients with depression will have problems concentrating and paying attention. This can further result in symptoms of agitation, restlessness and irritability.
Sleep Disturbances
According to the NIH, another clinical symptom of depression is sleep problems. Patients may have problems sleeping, or they may sleep excessively. If the patient suffers from excessive sleeping, he may fall asleep during the day. These sleep disturbances may prevent the patient from getting enough sleep every night, which can lead to other symptoms.
Fatigue
Along with the symptoms of sleep problems, depression patients also experience fatigue, according to the NIH. As a result of the fatigue, patients may have a lack of energy and feel sluggish.
Weight Changes
Changes in weight can also occur as a result of depression. According to the NIH, patients can either gain weight or lose weight. These weight changes can happen suddenly, and may also be drastic changes.
Loss of Interest in Activities
The final major clinical symptom of depression is a loss of interest, according to the Mayo Clinic. Depression patients may withdraw from their daily activities, even ones done for pleasure. The loss of interest can extend into the patient no longer completing his obligations at work or home. In addition from withdrawing from activities, the patient may also pull away from the people around him.
