While family physician Winnie Soon was treating a patient for diabetes, she realised that the woman had a deeper problem - she was sinking into depression because of a bereavement, and it was affecting her physical health.

She referred the patient to a psychologist and the woman was later sent for counselling. Dr Soon was able to recognise her condition because of training she had received.

Since 2012, Khoo Teck Puat Hospital (KTPH) and the Institute of Mental Health (IMH) have been training primary care doctors - such as general practitioners and polyclinic physicians - to pick up on signs of mental illness, in an effort to detect cases earlier and reduce the stigma surrounding the seeking of help for such problems.

Yesterday, the National Healthcare Group Polyclinics (NHGP) revealed that between October 2015 and last September, it dealt with 2,800 mental health cases - some of which involved patients who initially came in with other problems.

The scheme is a collaboration between NHGP, KTPH and the IMH and involves three polyclinics in Ang Mo Kio, Yishun and Woodlands.

Every month, each sees roughly 30 patients with mental health issues, especially anxiety and depression.

These are often picked up when patients are seeking treatment for other medical problems.

Dr Soon, a consultant with NHGP, said physical ailments such as chronic headaches or irritable bowels can sometimes be signs of a mental issue.

"Managing both physical and mental health conditions is important because they are connected," she added. "If you do not manage one of them, you find that the other may not be so well managed as well."

Before the scheme was launched in 2012, many patients with mental health issues would be referred to hospital for treatment. Now, four out of five patients seen at polyclinics can remain there.

More severe cases - such as patients who do not respond to medication or are suicidal - are referred to either KTPH or the IMH.

The two institutions are also training others in the community - such as voluntary welfare organisations - to pick up on signs that someone may need mental health help.

Dr Chan Keen Loong, a senior consultant in KTPH's department of psychological medicine, said the changes have helped to free up resources so that more serious patients can be seen faster.

The waiting time for a first appointment is now down from eight to 12 weeks to about two.

"Now we are able to focus more time and attention on the cases that are more serious. Not everyone will see a doctor," he said, adding that some patients require only counselling. "Not everyone's mental health issues will need medication."