More than 30 US states have launched peer specialist programmes, according to a recent report in Stateline, a publication of US-based non-profit The Pew Charitable Trusts. People with mental illness who are helped by peers tend to have more longer-lasting recoveries.

According to the Hospital Authority Mental Health Service Plan for Adults 2010-2015, the number of people with a mental disorder in Hong Kong is estimated at between one million and 1.8 million.

Chui says the life experience that a peer specialist gains in overcoming mental illness is something professionals can't get from training.

"[Chan] is better than us in this respect," says Chui. "Her empathy and first-hand understanding of the difficulties in battling the disease make her the ideal person to help patients set recovery goals. It's much better than us just telling the patient that they will recover if they stick to the medicine regimen. That she beat the disease, and could eventually stand on her feet and hold a full-time job, also provides a persuasive case to patients that they can do the same."

Armed with some non-clinical training in fields like pharmacology, Chan helps patients stick with their medication, find jobs and build social support networks. Her work duties involve attending case meetings with doctors, counselling patients and their families, and organising focus groups with patients.

"As a former patient, she provides perspectives that we have never thought about. The doctors actually get inspiration from her; she makes us more patient-oriented in our treatment," Chui says. Chan has counselled over 100 patients so far. The majority suffered from bipolar disorder, and the rest had depression.

Chan has battled mental illness for 16 years. "I spent over 10 years getting it under control, and I am still on medication," she admits. Born on the mainland, her family moved to Hong Kong in the 1970s. She graduated from secondary school, and studied engineering at Purdue University in the US.

Her first job was with the Dow Chemical Company, headquartered in Michigan. She quickly rose through the ranks to become a business development manager at the age of 30. But at the peak of her career, she was diagnosed with bipolar affective disorder.

"It might have been caused by stress. I was in high spirits at night, and couldn't sleep, even though I was tired. The jet lag from work trips made it worse," Chan says.

She sought medical help in the US and Hong Kong. She first received treatment in 1998 at Queen Mary Hospital's psychiatric ward. In 2002, her condition worsened and she told her company, which let her go with a "nice severance package".

She returned to her husband's hometown in Indiana and opened a flower shop with him "as a way to turn over a new leaf in life". But the business folded after a blizzard in 2008 cut customer numbers. The failure caused a relapse of her illness.

In 2009, she returned to Hong Kong alone to seek treatment and find a new job. "I lost a lot of confidence from the business failure. I tried to find a job in my previous field, chemical engineering, but failed. To survive, I worked as a cashier, real estate agent and tutor. But after I told my employer about my mental condition, I was fired from my tutoring job. So I was unemployed for a time."

She had another relapse, ending up in hospital. "I didn't return calls from my husband during this period, and we divorced in 2010." When she was at rock bottom, she saw the job advertisement for the peer specialist placed by the Hospital Authority.

Colleagues have discovered new perspectives in treatment from working with Chan, says Jolene Mui Hang-chun, a nurse consultant in community psychiatry." We recently asked more than 90 staff for their views on Chan's work. They said Chan helps them know what they should pay attention to when communicating with the patients," says Mui.

"Recovery is much more than medication. After the condition stabilises with the help of medicine, there's a long road to recovery and Chan helps us understand what needs to be done.

"Many of our patients get discharged and refuse to take their medication, and get sent back to the hospital again. Chan comes in at this stage to explain to patients why taking medicine is important for their recovery."

Chan's own refusal to take her medication led to a bumpy recovery, with several relapses.

"Mental patients are afraid of medicine because of the side effects, like getting fat and feeling thirsty all the time," she says. "But what makes them most reluctant is the sense of stigma that comes with it. It's like you are admitting that you have mental illness if you take the medicine, and mental illness is something that still brings discrimination from society.

"When counselling patients, their experience strikes a chord with me, because I go through the same thing myself. I help them set simple goals. One patient's goal is to be able to go home to cook a meal for her family every day. Many cases are young people who suffer from bipolar disorder, but are still holding a job. I advise them on how to work, and battle the disease at the same time."

Mui says Chan's words often have more effect on patients' families than those of medical professionals. "Many patients have overprotective family members who want to do everything for them. But that makes the patient feel worthless," says Mui. "Using her own experience, Chan explains to them that doing so is counterproductive. Family members usually mend their ways after listening to her."

Chui says there's plenty of scope for the peer specialist scheme to expand in Hong Kong's mental hospitals. The hospital cluster in New Territories West serves 1.1 million people, but has only one peer specialist. In Holland, there is one for every 12 to 15 frontline staff, says Chui.

Mui says the peer specialist model needs further development before it expands, stating examples such as recruiting peer specialists with different types of mental illness to provide more specific counselling and help.