context: Yes, clinical depression is a serious, but treatable, mental illness. It is a medical condition, not a personal weakness. It is also very common. Major depression is a clinical syndrome that affects about 6.7% of the U. S. population over age 18, according to the National Institute of Mental Health. Some estimate that major depression may be as high as 15%. Everybody at one point or another will feel sadness as a normal reaction to loss, grief, or injured self-esteem, but clinical depression, called "major depressive disorder" or "major depression" by doctors, is a serious medical illness that needs professional diagnosis and treatment. Yes. Children are subject to the same factors that cause depression in adults. These include: A change in physical health, life events, heredity, or inheritance, environment, and chemical disturbance in the brain. It is estimated that 2.5% of children in the U. S. suffer from depression. In adolescents, it is estimated to be 4% to 8%. Depression in children is different from the "normal" blues and everyday emotions that are typical in children of various ages. Children who are depressed experience changes in their behavior that are persistent and disruptive to their normal lifestyle, usually interfering with relationships with friends, schoolwork, special interests, and family life. It may also occur at the same time as (or be hidden by) attention deficit hyperactivity disorder ( ADHD), obsessive-compulsive disorder ( OCD), or conduct disorder ( CD). No. Lack of sleep alone cannot cause depression, but it does play a role. Lack of sleep resulting from another medical illness or the presence of personal problems can intensify depression. Chronic inability to sleep is also an important clue that someone may be depressed. Common triggers of depression include: Family history of depression. An abnormal reaction over the loss of a loved one through death, divorce, or separation. Interpersonal disputes. Physical, sexual, or emotional abuse. Major life events such as moving, graduating or retiring, etc. Serious illness. Major, chronic, and terminal illnesses often contribute to depression. These include cancer, heart disease, stroke, HIV, Parkinson's disease, and others. Substance abuse. Street drugs or heavy alcohol use can cause mood changes that mimic depression or other mood disorders. In addition, some people with substance abuse problems also may have depression, bipolar disorder, or other mood problems even when they are not using mood-altering substances. Being socially isolated or excluded from family, friends, or other social groups. Alternative therapy describes any treatment or technique that has not been extensively scientifically documented or identified as safe or effective for a specific condition. Alternative therapy involves a variety of disciplines that include everything from diet to mental conditioning and lifestyle changes. Some of these have been found to be effective for treating depression. Exercise, sometimes considered an alternative treatment, has gained increasing evidence for its ability to treat mild to moderate forms of depression. Examples of alternative therapies include acupuncture, guided imagery, chiropractic care, yoga, hypnosis, biofeedback, aromatherapy, relaxation, herbal remedies, massage, and many others. If you are interested in trying any of these options, talk to your doctor. Illnesses that can lead to depression are usually major, chronic, and/or terminal. When an illness is causing depression, there is often long-term pain or physical disability present or there is a sudden change in lifestyle. Depression causes illness in a different way. Like psychological stress, it can weaken the immune system (cells involved in fighting disease and keeping you healthy), allowing a person to get more colds or the flu. There is often a notable presence of "aches and pains" with no particular cause. Having depression may also cause the symptoms of another medical illness to last longer and intensify its symptoms, but the true relationship of depression-induced illness, in terms of major disease, has not been thoroughly defined. It is important to seek the advice of your doctor if you think you or someone you know may have depression. Your primary care doctor is a good place to start. He can screen you for depression and develop a treatment plan to help manage your symptoms. MAOIs, or monoamine oxidase inhibitors, are effective antidepressant medicines that have been used for years. Typically prescribed for people with severe depression, MAOIs improve mood by increasing the number of chemicals in the brain that pass messages between brain cells. They have proven to work just as well as, if not better than, other antidepressant drugs, but they have more possible food and drug interactions. Medicines to avoid when taking MAOIs include all SSRIs (a group of antidepressants that includes Prozac and Paxil) and certain pain medicines, including Demerol and tramadol. There are also some cough medicines, decongestants, and blood pressure medicines that should not be taken with MAOIs. Foods to avoid when taking MAOIs include aged cheeses and meats, pickled or smoked foods like sauerkraut or meat, and aged or fermented foods such as soy sauce or tap beer. It is important to tell your doctor about any medicines you are currently taking. Be sure to discuss the limitations, interactions, and possible side effects of MAOIs. Women develop depression twice as often as men. One reason may be the various changes in hormone levels that women experience. For example, depression is common during pregnancy and menopause, as well as after giving birth, suffering a miscarriage, or having a hysterectomy -- these are all times when women experience huge fluctuations in hormones. Premenstrual syndrome ( PMS) and premenstrual dysphoric disorder ( PMDD), an extreme form of PMS, may also cause depression. No. Most people who suffer from depression do not attempt suicide, but according to Mental Health America, 30%-70% of suicide victims have suffered from some form of depression. This figure demonstrates the importance of seeking professional treatment for yourself or someone you love if you suspect depression. Having experienced an episode of major depression does put a person at greater risk for future episodes, but not everyone who has recovered from depression will experience it again. Sometimes depression is triggered by a major life event, illness, or a combination of factors particular to a certain place and time. Depression can also occur for no obvious ''reason." Getting the proper treatment for the correct amount of time is crucial to recovery and in helping prevent or identify any future depression. If left untreated, various types of depressive disorders can last for months or sometimes years. A major depressive episode is characterized by a set of symptoms that typically lasts for a few months. Seasonal depression, or SAD, usually extends throughout the winter months and continues to improve during spring and summer. Bipolar disorder is characterized as "ups" (periods of mania) and "downs" (periods of extreme depression). Though these phases may change rapidly or slowly, bipolar depression may last until an effective treatment is found. Dysthymia, commonly referred to as persistent depressive disorder, is a mild and sometimes less recognizable form of depression that lasts for 2 years or more in adults. It disrupts quality of life and may lead to major depression if left untreated.