Everyone experiences feeling "down" now and again, but clinical depression symptoms are often pronounced, chronic and prolonged. This disease affects close to 20 million Americans every year, and it's an illness that can be treated with therapy and drugs.

Unfortunately, less than half of the people suffering from clinical depression will actively seek treatment. They mistake the symptoms associated with this debilitating affliction as a normal course of life, believing they can deal with it alone. However, left untreated, this affliction can negatively impact a person's personal life, work life and general ability to function.

Then, if identifying the clinical depression symptoms is so critical, how do you do it? To find out, read on.

Chronically Feeling Sad or Down

A consistent and unrelenting feeling of sadness or anxiousness can often be a sign of the disease. Most doctors won't diagnose the disease, though, until the symptom has persisted over a period of several weeks.

Sleeping and Eating Patterns Change

A sudden change in sleeping patterns - like sleeping a lot or not sleeping at all - can also be symptoms associated with the disease. Reduced appetite accompanied by weight loss is another indicator, as is increased appetite and subsequent weight gain.

Since an increase or decrease in appetite or a change in sleeping patterns can affect the body physically, these symptoms can even become contributing causes.

Change in Sex Drive

Often patients diagnosed with the disease complain of a significantly reduced interest in sex. This lack of interest can also extend to other pleasurable activities

Irritability and Anger

When individuals deal with surmounting stress of clinical depression, they can often become aggressive, irritable or moody.

Mysterious Physical Ailments

Many people suffering from this plight will see their disease manifest itself in incurable and mysterious physical ailments such as chronic pain, headaches or digestive problems.

Trouble Focusing and Remembering

Are you having trouble focusing on tasks at work or school? Losing your ability to make concise decisions or remember small details? This reduced mental capacity can often be an identifying symptom.

Experiencing Abnormal Sense of Guilt

People living with or suffering from clinical depression may experience extreme feelings of guilt or worthlessness - such as being no good and everyone knows it. Because of this, thoughts of suicide and death are not unusual.

Clinical depression symptoms are not a normal part of being human, nor are they just part of a woman's natural cycle. Depression is a serious medical illness that affects millions of people, but it can be treated and even cured. The real tragedy of this debilitating disease is that it so often goes untreated.