UQ School of Public Health Ph.D. scholar Xiaolin Xu said women who experienced symptoms of depression, even without a clinical diagnosis, were at risk of developing multiple chronic diseases.
"These days, many people suffer from multiple chronic diseases such as diabetes, heart disease, stroke and cancer," Mr. Xu said.
"We looked at how women progress in the development of these chronic diseases before and after the onset of depressive symptoms."
The Australian Longitudinal Study on Women's Health followed healthy, middle-aged women with no previous diagnosis of depression or chronic illness over 20 years.
The study found 43.2 percent of women experienced elevated symptoms of depression and just under half the cohort reported they were diagnosed or taking treatment for depression.
Women from the depressed group were 1.8 times more likely to have multiple chronic health conditions before they first experienced depressive symptoms.
"Experiencing depressive symptoms appeared to amplify the risk of chronic illness," Mr. Xu said.
"After women started experiencing these symptoms, they were 2.4 times more likely to suffer from multiple chronic conditions compared to women without depressive symptoms."
The research suggests depression and chronic diseases share a similar genetic or biological pathway.
"Inflammation in the body has been linked to the development of both depression and chronic physical diseases," he said.
"Chronic diseases, like diabetes and hypertension, are also commonly associated with depression."
These findings help strengthen healthcare professionals understanding of mental and physical health.
"Healthcare professionals need to know that clinical and sub-clinical depression (elevated depressive symptoms) can be linked to other chronic physical conditions," he said.
"When treating patients for these symptoms, healthcare professionals must realize these people are at risk of developing further chronic illness."
Women with both conditions were more likely to come from low-income households, be overweight and inactive, smoke tobacco and drink alcohol.
"Maintaining a healthy weight, exercising regularly, eating a balanced diet, and reducing harmful behaviors could help prevent and slow the progression of multiple chronic diseases."