July 28, 2004 — Feeling blue? You’re not alone. A new study shows American adults feel sad or depressed an average of three days a month.

Researchers found people who were depressed more often than that were also more likely to engage in unhealthy behaviors, such as cigarette smoking and physical inactivity.

The study also shows that women reported an average of one more day of feeling sad per month than men (3.5 days versus 2.4 days). But young adults aged 18-24 reported the highest number of days with depressive symptoms, and older adults over age 60 reported the fewest.

Researchers say that most people who feel sad, blue, or depressed several times a month probably do not have a diagnosable mental disorder, but those above a certain threshold of depressed days may be at increased risk for mental and physical illness.

According to the American Psychiatric Association, depression is diagnosed when a person experiences persistent feelings of sadness or anxiety or a loss of interest or pleasure in usual activities in addition to other depressive symptoms for at least two consecutive weeks.

How Often Do Americans Feel Blue?

In the study, researchers at the CDC analyzed how more than 166,000 American adults answered the question: “During the past 30 days, for about how many days have you felt sad, blue, or depressed?”

The information was gathered as a part of the annual U.S. Behavioral Risk Factor Surveillance System telephone surveys from 1995 to 2000 and the results appear in the current issue of Health and Quality of Life Outcomes.

Researchers found the respondents reported an average of three days of feeling depressed in the last 30 days. Nearly 43% reported one or more sad days, and nearly 8% reported 14 or more days of feeling down.

The study also shows that the number of sad days was closely associated with a variety of health indicators, for example:

• People who exercised had 1.3 fewer depressed days per month than those who didn’t.
• People who never smoked had 2.4 fewer depressed days than those who smoked more than one pack of cigarettes per day.
• People who were unable to work experienced the most depressed days, 10 on average.
• Obese or underweight people reported more depressed days than those who were normal weight or overweight.
• People who considered themselves in excellent health had only 1.6 depressed days compared with 11 depressed days per month reported among those in poor health.

Researchers say the findings highlight the relationship between feeling sad, blue, or depressed and engaging in behaviors risky to health.