Depression is still a taboo topic, and one-fourth of patients who have depressive disorders are not diagnosed, a new study shows.

Researchers surveyed 1,054 adults who had participated in the California Behavioral Risk Factor Survey System, USA Today reported.

Suffering in Silence: Reasons for Not Disclosing Depression in Primary Care was published in the Sept./Oct. issue of the Annals of Family Medicine journal. Researchers were led by Robert A. Bell of the University of California, Davis, the Web site WebMD.com reported.

In the survey, 43 percent of patients had at least one reason for not talking about their depression to a primary care doctor.

The biggest reason for not disclosing symptoms, the study showed, was that patients were concerned their doctor would recommend antidepressants.

Some patients did not think it was their physician's job to talk about depression.

There were also privacy concerns, as participants worried about who might view their records, such as an employer, the Web site Psych Central reported.

Patients also fear being referred to a counselor or psychiatrist. They also do not wish to be labeled as a psychiatric patient.

Ironically, the authors of the study wrote, those who most subscribed to potential reasons for not talking to a primary care physician about their depression tended to be those who had the greatest potential to benefit from such conversations--individuals with moderate to severe depressive symptoms.

The National Institute of Mental Health notes that depression affects both men and women, but that women are more likely to be diagnosed. Still, the NIMH notes that many women never seek treatment for depressive illnesses.