Depression means a wide range of mental health disorder. The people who have depression will loss of interest and enjoyment in ordinary things and experiences (absence of positive affect). They may also in a low mood in range of associated emotional, cognitive, physical and behavioral symptoms (National Institute for Health and Clinical Excellence, 2010) Beside, depression also can be define as sad and loss of interest for at least two weeks, at least four of the symptoms that affecting our daily life. The symptoms had been divided into two groups, physical symptoms and psychological symptoms. Physical symptoms include insomnia, change in body weight, fatigue and sluggish movements and restlessness. On the other hand, psychological symptoms include feeling guilt, reduce concentration and suicidal ideation. (Jorm, Allen, Morgan, Ryan & Purcell, 2013)
Depression becomes a common phenomenon in this society. According to the World Health Organization (WHO), they predict that around 350 million people are affected by depression around the worldwide (World Health Organization, 2012). It had been forecast that depression will be the second most important health condition which just after heart disease by year 2020 (Chui, 2012). On the other hand, according to the Institute of Mental Health Castle Peak Hospital, it find out that around 5% of male and 10% of female are affected by depression in developed countries(Chui, 2012).
In Hong Kong, a telephone-interviewed survey which asses the prevalence of depressive episodes had randomly selected more than 5000 adults who aged 18-64 in 2004. The result of this survey shows the overall prevalence of female and male is 9.7% and 6.8% separately and total is 8.4% (Centre for Health Protection, 2012) In addition, a study shows different level of depressive symptoms by using Chinese Beck Depression Inventory (BDI) on 966 secondary school students. It indicates that 36.4% of students who aged 14-17 have mild depressive symptoms, 14.7 % have moderate depressive symptoms and 4.2% have severe level of depressive symptoms (Centre for Health Protection, 2012).
The level of depression can be arranged by the Kessler psychological distress scale (K10) and Beck Depression Inventory (BDI). If the people in health mental distress, it would get 0-9 marks in BDI or marks lower than 20 in K10. People in mild mental distress, it would get 10-19 marks in BDI or marks between in K10. If the mark of BDI between 20-29 or 25-29 marks in K10, the people are in a moderate level. If people in severe level, the marks of BDI will be 30-60 or get more than 30 marks in K10. A survey in 2011/2012 shows different level of mental distress in junior form students and senior form student. The results are as follow: (Baptist Oi Kwan Social Service, 2012)
Level of mental distress Health Mild Moderate Severe
BDI (Junior form) 60.4% 25.9% 8.4% 5.3%
BDI (Senior form) 50.5% 30.5% 12.1% 6.9%
K10 (Junior form) 51.3% 23.9% 12.7% 12.1%