TORONTO - Being aware of cultural differences should help doctors better diagnose depression in Chinese and other East Asian patients, who tend to emphasize physical complaints and minimize psychological symptoms, researchers suggest.

In a study that compared two groups of patients assessed for depression in outpatient clinics - one in Changsha, China, and the other in Toronto -- researchers found that the Chinese focused more on physical symptoms common to the condition, such as fatigue, low energy and headaches.

The Canadian patients, in contrast, were more apt to complain of psychological aspects of depression, including feelings of sadness, guilt and worthlessness, said co-author Dr. Michael Bagby, director of clinical research at the Centre for Addiction and Mental Health (CAMH) in Toronto.

The collaborative study by Canadian and Chinese scientists, recently published in the Journal of Abnormal Psychology, involved more than 200 participants from the two countries, who were assessed for depression using similar diagnostic methods.

"Really what we found was the more anonymous or the more observed the manner in which depressive symptoms were asked about, the more the Chinese would not talk about the psychological, but more about the somatic (physical)," Bagby said in an interview Tuesday.

"Whereas, regardless of how we assessed depression in the western (Canadian) sample, it was always the emphasis on the psychological." In fact, he said, westerners tend to "over-express psychological symptoms," making the cultural differences seem even greater.

Bagby said it has long been suggested that the onus by East Asians on physical symptoms is related to a strong stigma - "loss of face" - associated with any kind of mental illness.

"That's what it is," he said. "It's shame. And because of the collectivist society, you're bringing shame onto your family and shame to yourself."

"There's no shame in having a physical problem, but there is a shame in having a psychological problem. And I think that is probably one possible explanation of why we see these differences."

Bagby said a followup study is being done to see whether Japanese and Koreans with depression also identify physical symptoms above the psychological.

The researchers also want to study Chinese immigrants in Canada to see if acculturation to a western society over time alters how they experience depression and what type of symptoms they express most.

Bagby said Canadian doctors dealing with East Asian patients must realize that they may not fully meet the North American diagnostic criteria for depression because of an onus on physical manifestations of the disease.

His experience with assessing depression in young people from Hong Kong, China and Taiwan is that once they are assured that the condition will be kept confidential from their families, the patients tend to open up more.

"What we find is if you're sensitive to the fact that this will happen and you're also sensitive to the fact of the context where they're expressing this, then you might get more psychological symptoms," he said.

"If a Chinese immigrant comes and doesn't seem fully acculturated or is living with family or there's huge family pressure still ... you need to be aware of the potential cultural explanation for a possible differential expression (of depression)."