Unemployed people generally experience three major types of distress. The first is financial distress. They have to face financial ruin, and many begin to lose their lifetime savings and even their homes [2]. The second is physical health. Medical symptoms such as diabetes, hypertension, and coronary heart disease are associated with unemployment [3-5]. The third is mental health. Poor mental health is common among the unemployed [6,7] and unemployment is associated with higher levels of depression [8,9], suicide [10] and anxiety [11].

Published studies on the relationship between unemployment and mental health have extensively focused on developed countries in the West [7-10] and unemployed urban residences with labor insurance (e.g. nurses, white-collar employees, and stable workers) [12-14]. These studies not only have significantly advanced current knowledge concerning the mental health of unemployed urban individuals in the Western countries but also have motivated new important research questions. For example, what is the general relationship between unemployment and mental health during the economic crisis in East Asian countries such as China? What is the specific relationship between unemployment and mental health during the economic crisis among migrant workers as the typical urban workforce in China, especially those who are unemployed and without unemployment insurance?

The present study seeks to go beyond existing studies to further examine mental health among unemployed migrant workers during the economic crisis by making the following four specific efforts.

First, we explore mental health in the Chinese context. Either economic boom [15] or crisis [16-19] can generate mental problems. Many Chinese people have suffered double distress from both rapid economic growth and an unprecedented economic crisis in the recent years. Lee’s research group, for instance, found that economic contraction triggered by a global economic crisis of 2008 was associated with a higher risk of depression [20].

Second, we have chosen unemployed migrant workers as our subjects. In China, there are around 120 million rural–urban migrants, accounting for about 25% of the working population of the entire country [21]. The economic crisis of 2008 has forced thousands of labour-intensive enterprises to go bankrupt in China and hundreds of thousands of migrant workers to lose their jobs. According to China’s National Statistics Bureau, by the end of 2008, the registered unemployed population in urban areas was 8.86 million, and about 20 million of 120 million peasants who went to cities for work in China have lost their jobs [22]. In recent years, the mental health of migrant workers in China has received close attention by researchers [21,23-25]. For example, in an important study, Wong and his collaborators evaluated the mental health status of 475 migrant workers in Shanghai by using the Brief Symptoms Inventory (BSI). They found that migrant workers experienced more stress in “interpersonal tensions and conflicts” and were more likely to be mentally unhealthy [23].

Third, we focus on two aspects of unemployed workers, their duration of unemployment and coping strategies used. First, duration of unemployment refers to the time period during which the person recorded as unemployed was seeking or available for work. The positive linear relationship between duration of unemployment and mental health has been well studied in a number of populations [26-29]. Stankunas’ group, for instance, surveyed 429 unemployed persons in Lithuania and found that long-term unemployed persons had more episodes of depression in the past 12months in comparison with short-term unemployed ones [26]. Second, coping strategies, according to the vulnerability-stress model proposed by Zubin and Spring [30], mediate the potentially negative effects of daily stressors and thus influence mental health [31,32]. The development of a successful coping behavior is likely to reduce stress and help a person to solve personal problems and maintain psychological balance and health [33]. People with a lower level of mental health have been shown to use more avoidance or other negative coping strategies, whereas people with a higher level of mental health use more problem-focused strategies aimed at dealing with the stressors themselves [32]. As one of the earliest empirical efforts, Li and his collaborators found that migrant workers were more inclined to turn to friends than family members and only in 1% of the cases sought professional help [21]. Thus, it is theoretically and practically important to examine duration of unemployment as a stressor and coping strategies as stress management skills in order to understand how unemployed migrant worker in China develop and deal with their mental problems.