Clinical depression is so common, so potentially damaging, and so often undiagnosed that a board coalition of experts now recommends that primary care providers screen everyone over 12 for what is the most common of all mental disorders.

We all get depressed. It's not even just when there are obvious reasons for us to feel that way. Sometimes we're just "down," "off," "in a funk." Every now and then a day more or less in bed, even when we're physically well, seems just what the proverbial doctor ordered.

Nonetheless, depression—the most common of all mental disorders, according to the American Psychological Association—is a significant enough health risk that a panel of experts on preventive medicine recently recommended that primary-care physicians/providers intermittently screen all adults for depression, regardless of risk factors; and that all children 12 to 18 be intermittently screened for major depressive disorders.

These recommendations were made by the U.S. Preventive Services Task Force, an independent, volunteer panel of national experts—culled from the fields of internal medicine, family medicine, pediatrics, behavioral health, obstetrics and gynecology, and nursing—in prevention and evidence-based medicine. The Task Force, which submits an annual report to Congress, bases its recommendations "on a rigorous review of existing peer-reviewed evidence[, which] are intended to help primary care clinicians and patients decide together whether a preventive service is right for a patient's needs."

The rationale for the Task Force recommendation is straightforward: "Depression is among the leading causes of disability in persons age 15 years or older," and it "is common in primary care patients."

Referring to depression as a disability may seem like an overstatement, but that is a matter of semantics. In the medical field 'depression' is shorthand for a number of related conditions. The National Institute of Mental Health breaks them down as follows:

Major depression—severe symptoms that interfere with your ability to work, sleep, study, eat, and enjoy life. An episode can occur only once in a person’s lifetime, but more often, a person has several episodes.

Persistent depressive disorder—depressed mood that lasts for at least 2 years. A person diagnosed with persistent depressive disorder may have episodes of major depression along with periods of less severe symptoms, but symptoms must last for 2 years.

Psychotic depression, which occurs when a person has severe depression plus some form of psychosis, such as having disturbing false beliefs or a break with reality (delusions), or hearing or seeing upsetting things that others cannot hear or see (hallucinations).

Postpartum depression, which is much more serious than the "baby blues" that many women experience after giving birth, when hormonal and physical changes and the new responsibility of caring for a newborn can be overwhelming. It is estimated that 10 to 15 percent of women experience postpartum depression after giving birth.

Seasonal affective disorder (SAD), which is characterized by the onset of depression during the winter months, when there is less natural sunlight. The depression generally lifts during spring and summer. SAD may be effectively treated with light therapy, but nearly half of those with SAD do not get better with light therapy alone. Antidepressant medication and psychotherapy can reduce SAD symptoms, either alone or in combination with light therapy.

Bipolar disorder, also called manic-depressive illness, is not as common as major depression or persistent depressive disorder. Bipolar disorder is characterized by cycling mood changes—from extreme highs (e.g., mania) to extreme lows (e.g., depression).

While the Task Force doesn't expand on the commonality of depression, the World Health Organization estimates that 5% of the global population experience at least one form of clinical depression each year, with fewer than half receiving any kind of treatment. Meanwhile, the Centers for Disease Control puts the figure at 7.6%.

That percentage is far higher for certain groups. The National Institute of Mental Health reported that in 2014 11.4% of U.S. adolescents suffered a depressive episode of at least two weeks in length; and that 15% of all mothers experience postpartum depression within a year of giving birth. Things are even worse for those living in poverty, with the Centers for Disease Control reporting that over 15% of poor Americans suffer from depression.

Depression has been linked tocardiovascular disease, diabetes, stroke, and Alzheimer's disease, not to mention the obvious: suicide. And considering that both the frequency and severity of depression symptoms tends to increase over time, the value of diagnosing depression early is self-evident. So heeding the U.S. Preventive Services Task Force's new recommendations on depression screening will contribute to a healthier populace.

About the Author:

Except for a four-month sojourn in Comoros (a small island nation near the northwest of Madagascar), Greggory Moore has lived his entire life in Southern California.  Currently he resides in Long Beach, CA, where he engages in a variety of activities, including playing in the band MOVE, performing as a member of RIOTstage, and, of course, writing. 

His work has appeared in the Los Angeles Times, OC Weekly, Daily Kos, the Long Beach Post, Random Lengths News, The District Weekly, GreaterLongBeach.com, and a variety of academic and literary journals.  HIs first novel, The Use of Regret, was published in 2011, and he is currently at work on his follow-up.  For more information:  greggorymoore.com