mong the many challenges confronting children and adolescents globally, few if any is more urgent than depression. Childhood and adolescence onset depression has been associated with greater rates of depression recurrence (Merry, McDowell, Wild, Bir, & Cunliffe, 2004), faster relapse rates (Alloy et al., 2006b), increased chronicity of episodes and longer duration of illness (Lewinsohn, Shankman, Gau, & Klein, 2004). Further, a number of longitudinal cohorts studies have tested the developmental continuity between youth and adulthood diagnoses, and found that the link is both homotypic and heterotypic, i.e., youth depressive symptoms lead to adult depression and other types of mental illness (Stringaris & Goodman, 2009;2013). Depressive episodes in childhood and adolescence often trigger debilitating ripples across multiple life domains, including poor academic achievement at school, conflicting relationships with family members and peers (Kaminer, Conor, & Curry, 2007), and the most serious outcome is suicide (Centers for Disease Control, 2015).

Suicide attempts are the leading cause of hospitalization for Chinese youths as well as the leading cause of death in China (Hesketh, Ding, & Jenkins, 2002).

In 2014, an estimated 2.8 million youth aged 12 to 17 in the United States had at least one major depressive episode in the past year (Substance Abuse and Mental Health Services Administration, 2014). This number represented 11.4% of the U.S. youth population (SAMHSA, 2014). These figures, however, may be an underestimate of depressive symptoms among youth. Besides major depression, recent reports suggested an increasing number of children and adolescents experience depressed mood, subsyndromal symptomatic symptoms, and minor depression (Lewinsohn et al., 2004). Thus, the focus of the present review is on youth depressive symptoms. It is important to assess not only clinical depression but also the presence of depressive symptoms that might lead to a more severe disorder in the future. In the current review, depression refers to the presence of depressive symptoms.

Sharply contrasted with the amount of research conducted in U.S., very limited epidemiological studies on youth depressive symptoms have ever been conducted in the three Chinese contexts of mainland China, Hong Kong, and Taiwan. Even though no official estimate of prevalence is available in these areas, there have several attempts to identify the presence, prevalence, and ecological risk factors of youth depression there recently. Since it has been found that Chinese youth has not been spared from depressive symptoms (Zgambo, Kalembo, He, & Wang, 2012) and the demand for effective and efficient prevention and intervention continues to rise, a comprehensive systematic review is needed to provide an empirical rationale for future research and preventive intervention programs for Chinese youth.

Importantly, it is well-known that although depression could be identified across diverse cultural contexts, cultural differences in the expression, manifestation, reporting, and predicting factors of depression had been well established among racial groups (American Psychiatric Association, 2013).Thus, identifying context-relevant factors which made Chinese youth susceptible to depression is critical for this largest A ethnic group in the world. As the word depressed is absent from Chinese language until the end of 20 th century, and certain Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnosis do not correspond equivalently to the categories of symptoms recognized by Chinese population (Kalibatseva & Leong, 2011), examining depressive symptoms among youths from Chinese contexts would sieve out cultural phenomenon, and ultimately decrease misdiagnosis and undertreatment of depression among the target population.

The current review seeks to accomplish two purposes. First, an up-to-date summary of youth depression literature in mainland China, Hong Kong, and Taiwan will be provided, with an emphasis on prevalence of depressive symptoms among Chinese children and adolescents. Second, to systematically review research articles that studied the associations between ecological risk factors and youth depressive symptoms, and to figure out context-relevantrisk factors for Chinese youth.

Since research on child and adolescent depressive symptoms are relatively few in the Chinese context, the initial search aims to be inclusive than limiting. Electronic databases (MEDLINE,Web of Science, JSTOR, ERIC, PsycINFO, and Google Scholar) were searched for empirical studies that examined depressive symptoms among Chinese youth. Search terms, including 'depressive symptoms among Chinese children and adolescents', 'youth depression in China', 'ecological risk factors associated with Chinese youth depression', 'depression prevalence among Chinese youth', 'childhood and adolescence mental health in China', were sought across all databases.

Articles were included if they were peerreviewed empirical articles that conducted in mainland China, Hong Kong, and Taiwan among children and adolescents aged 7 to 18 years old from 2000 to 2015 in English or Chinese. Given the large amount of variation existing in diagnosis of depression, development heterogeneity, and socio cultural contexts, studies that a) tackled clinical depression and any other kinds of internalizing problems (e.g., anxiety, somatic complaints, or social withdrawal) among youth, b) sampled participants younger than 7 or older than 18 years old, and c) surveyed sites outside of mainland China, Hong Kong or Taiwan were excluded. This process resulted in 89 evidence-based articles by screening abstracts. These articles were further screened for eligibility by scrutinizing full texts, and 32 were obtained and included in the review. Further, the bibliographies of these article as were then reviewed for additional sources pertinent to the study purposes. This process yielded an additional 5 journal articles. Summing up, 37 articleswere included in the current review.

The author read each article and input information relevant to the research purposes into a database. In order to address the purposes of the current review, sample characteristics, measurements on depressive symptoms, and primary ecological risk factors from each article were compiled and organized into substantive clusters and shown in Table 1.

Characteristics of the 37 selected studies were shown in Table 1. The 37 articles had a mean sample size of 2,366subjects (sd=3,610; median=1,162; ranging from 258 to 18,341). Approximately 70% (n=26) of the studies were performed in mainland China, 14% (n=5) were conducted in Hong Kong, and the rest (n= 6) in Taiwan. Among the studies conducted in mainland China, the capital city Beijing and urban Hunan provinces in mid-south have been studied most, whereas rural inland areas were studied the least.Among the articles included in the current review, 25 (68%) studies employed cross-sectional research design, whereas 12 (32%) employed longitudinal design.

In most studies, depressive symptoms were measured solely by self-report instruments. The particularly in Chinese contexts. In mainland China, the dramatic political and economic changes through the previous half century influence the actual prevalence of emotional disorders, such as depression and its reporting. When the personality cult of Mao Zedong prevailed in China, his bias on mental illness stigmatized the patients, manipulated public's perceptions, and impeded psychiatric treatment (Kleinman, 1986). Based on Mao's perspective, the outdated political systems, feudalism and capitalism were the chief culprits causing mental illness (Kleinman, 1986). The sociologist Arthur Kleinman has conducted multiple studies on mental illness in China. His book Social Origins of Distress and Disease: Depression, Neurasthenia, and Pain in Modern China (1986) stated that from clinicians to patients, no one admitted that mental health problems existing in contemporary China. Because people who opposed the communist regime or leaders, and/or advocated for personal rights were seen as mentally sick in China (Tsai & Levenson, 1997), patients who suffered from mental health problem have to ignore, deny and hide their mental disorder. Consequently, a commonly held view suggests that Chinese adults and youth, suffer little, if any, from mental illnesses such as depression (Yip, 2005). However, the current review has made it clear that this is not accurate. The prevalent rates of depressive symptoms among children and adolescents in mainland China ranged from 5.9% (Tepper et al., 2008) to 33% (Hesketh et al., 2002).

Western concepts of mental health are more immersed in Hong Kong and Taiwan due to historical reasons (Yip, 2005). Since Hong Kong and Taiwan are areas where traditional Chinese culture are mingled with Western modern culture, depressive symptoms are less often obscured by stigma, misconception, and shame compared with the mainland. That said, the reporting of prevalent rates among sampled youth in Hong Kong and Taiwan did not differ much from children and adolescents in the mainland. The studies conducted on Hong Kongese and Taiwanese youth psychological adjustment reported the prevalent rates ranging from 10% (Lin et al., 2012) to 20.9% (Chan, 2012). (Liu et al., 2009).

Gender also plays a critical role in the development of youth depressive symptoms.Nine studies examined gender as a potential predictor of depressive symptoms among Chinese youth and revealed a mixed picture. Five of these nine studies found female youth reported significantly higher level of depressive symptoms than did their male counterparts (Fan et 2002). Additionally, the negative cognitive style was linked to youth depression through the mediation and moderation of perceived low sense of control (Auerbach et al., 2010), negative coping styles (Chan, 2012; Ng & Hurry, 2011), and threat perception bias (Lu et al., 2013). Particularly, distorted cognition on self-weight is significant on adolescent depression. Adolescents who perceived themselves as overweight were more likely to experience depressive symptoms than those who perceived themselves as normal or underweight, regardless of their actual weight status (Tang et al., 2010;Xie et al., 2006). Life events: Eleven studies examined the effect of stressful life events on youth depression. Early childhood adversities and recent negative life events are strong predictors of depressive symptoms among youth. In particular, studies have identified child victimization, illness or death of family members and close peers, family economic loss, dissolution of Most peasants in rural China migrate to cities to make a living, leaving their children to be taken cared by grandparents or other extended family members.

Studies on rural youth have found that early separation with parents when parents migrate were associated with depression in children and adolescents (He et al., 2012;Wang et al., 2015). For example, Wang and colleagues (2015) surveyed 4,857 left-behind children and adolescents in Chongqing. They found that the early absence of parents and consequent in frequentparentchild communication put youth at greater risk for developing depression.

The 2008 Wenchuan earthquake is the most disastrous earthquake since the 1976 Tangshan earthquake in mainland China. More than 450,000 people are dead, missing, or injured in this devastating disaster, and 4.8 million people homeless (official figures retrieved fromhttp://www.scio.gov.cn/gzdt/ldhd/ 200809/t222722.htm). Fan et al. (2011) found that the higher degree of exposure to the earthquake was associated with higher level of youth depression. Exposure included youth experienced death, missing, injury of family members, house damage, property loss (other than house damage), and direct witness of the tragic disaster (Fan et al., 2011).

Farmers in Henan province sell blood for additional income to governmental and/or commercial blood centers. The farmers, who were not screened for HIV, hepatitis B/C, or other blood-borne infections, gave blood to collection centers, which "pooled the blood of several donors of the same blood type, separated the plasma, and injected the remaining red-blood cells back into individual donors to prevent anemia" (Fang et al., 2009;p.1054). Farmers often made repeated donations for cash. Such risky practices, along with contaminated medical equipment, contributed to virus spread to many others on a single visit. Many HIV-infected individuals in Henan and other HIV-epicenters progressed to AIDS and subsequently died, leaving their children orphaned. Fang and colleagues (2009) surveyed AIDS orphans, who had lost one or both their parents to AIDS, and who lived with HIV-infected parents. These youths consistently demonstrated poor mental health, including depressive symptoms, loneliness, and hopelessness (Fang et al., 2009).

Ecological Risk Factors of Depressive Symptoms in Chinese Youth: A Literature Review (Greenberger et al., 2000). Family environments that are less supportive and more conflictual are associated with greater depressive symptoms both concurrently and prospectively. Yu and Seligman (2002) investigated the psychosocial correlates of depression among children and adolescents in Beijing. Depressive symptoms were strongly related to family variables such as lower cohesion, lower expressiveness, and greater conflict. youth depression. In a large-scaled sample of 12,449 middle and high school students from seven major cities in China, Sun and colleagues (2012) explored the associations of self-perceived relative income inequality with depression. The researchers examined two types self-perceived relative income, one is household income relative to peers, the other is household income relative to their own past. The youth who perceived lower family of family environment, i.e., relationship, personal growth, and system maintenance, and found poorer family environment predicted more depressive symptoms. Assessing longitudinal associations between family environment and youth depression in 2,690 Taiwanese adolescents (mean age = 13), Sze and colleagues (2013) found higher perceived family cohesion in Grade 7 was associated with less increase in depressive symptoms from Grades 9 to 11. Family structure: Four studies examined family structure and youth depressive symptoms. Family structure is reflected in two forms, one is parents' marital status (single parent versus non-single parent), the other is number of children at home (single child versus nonsingle child). Divorce rate has continued to grow in recent years in China, studies that compared youth from intact and divorced families found that children in divorced families exhibit higher level of depressive symptoms than children from intact ones (Dong et al., 2002;. These studies provide evidence that single-parent family structure was a significant predictor for youth depressive symptoms in Chinese contexts.

Since the one-child policy from the 1980s, most city dwellers have only one child. Although a large amount of youth is the only one child in the family, very limited studies have examined their psychological development. Only two studies in this review examined the depressive symptoms among the singl e child versus non-single child. Both studies found depression was less common in single child compared with those with siblings (Hesketh et al., 2002;Yu & Seligman, 2002). More research is needed to conduct on single and nonsingle children and explore reasons when differences been detected. Family SES : Eight studies examined family SES as a potential risk factor for youth depressive symptoms. As economic booming and market -oriented economy happened in the last three decades, the variation in individual and family income is increasing. Low family SES was often linked with low parental education (Hesketh et (Liu, 2003) and parental unbridle predicted more depressive symptoms among youth. Youth who were often verbally or physically punished by parents reported higher level of depression concurrently (Yu & Seligman, 2002) and longitudinally (Wu, 2007). Parenting was also trickled down from parental messages. Child perceptions of parental negative messages regarding themselves, their world, and their future were found to be positively associated with depression, whereas positive messages had an opposite effect (Liu, 2003).

g) School-level risk factors Academic performance: Six studies have examined academic performance as a potential risk factor for depressive symptoms. Poor academic performance is a predictor of and a consequence of depressive symptoms in children and adolescents. Besides actual academic performance (Greenberger et al., 2000;Hesketh et al., 2002;Yu & Seligman, 2002), subjective self-perceived achievement performance was also predicting in youth depressive symptoms (Li & Zhang, 2008). Additionally, good academic achievement was a buffering factor that served to protect shy-sensitive children from developing depressive symptoms (Chen et al., 2013). In Chinese contexts where education is extremely emphasized, prevailing academic pressure was significantly associated with depression (Zhang et al., 2013). Peer relationships: Seven studies examined peer relationships as a predictor of depressive symptoms. Considering interpersonal harmony is greatly valued through traditional to contemporary collectivistic Chinese societies, difficulties in peer relationships significantly predicted youth depressive symptoms (Greenberger et al., 2000), whereas caring peer relationships protected youth from depression (Chen et al., 2012;Li & Zhang, 2008). Particularly for youth experiencing stressful life events, including parental migration, family issues, and achievement problems, SES in either type reported the higher level of researchers are more concerned about delinquent behaviors of youth. Chinese parents expect an ideal child who is academic excellent, obedient to authorities (i.e., parents and teachers), maintaining harmonious relationships with peers. Thus youth's emotional development has not been prioritized among parents. Third, there is common belief among Chinese that peer support moderated the association between the occurrence of negative events and depressive symptoms (Luo et al., 2011;Yang et al., 2010), in line with the buffering effect. Relationships with teachers: Three studies examined relationships with teachers as a risk factor for depressive symptoms. Interpersonal problems with teachers was predictive of depressive symptoms in children and adolescents. For example, in a student sample from the countryside of Chongqing, Guizhou, and Anhui, disharmonious relationships with teachers was significantly associated with youth depressive symptoms, and the negative effect was stronger among adolescents whose parents were absent (Luo et al., 2011).

V.

Taken together, there is limited research on the prevalence and ecological risk factors of youth depressive symptoms in mainland China, Hong Kong, and Taiwan, leading the current review to suggest youth depression is an underexplored parameter in the arena of Chinese youth psychological adjustment. However, the available research suggests Chinese children and adolescents are not spared from depressive symptoms, having rates ranging from 6% to 33%, and showing strong links between ecological risk factors and youth depression. This review highlights several important correlates of youth depressive symptoms, including age, gender, negative cognitions, stressful life events, family environment, family structure, family SES, parenting practices, academic performance, peer relationships, and relationships with teachers. This review found that the number of validated studies on youth depressive symptoms in the chosen areas is extremely low, especially when such studies are compared with those in Western countries. There are several possible factors leading to this observed phenomenon. First, the modern Western concept of emotional disorder is new to majority Chinese and not well accepted by indigenous people there. While the concept of 'depression 'was introduced to Asian countries by the end of the 1990s, people are not beginning to recognize depression till recently. Thus, the development of psychosocial research among children and adolescents is still in its infancy in Chinese contexts. Second, since youth mental health is subtle to detect and brings stigma to seeking help, Chinese parents and children will self-correct psychological maladjustment if they have any and will "automatically" grow up. Finally, in contrast to Western countries where research institutions and/or governments take the initiative to develop youth depression research, research institutions and/or governments in the three Chinese contexts do not spend much intellectual and financial effort on youth psychological development research. As such, the emphasis on Chinese youth depressive symptoms is far from enough.

The current review reflected that rigorous social science training and the spirit of evidence-based research is at its beginning stage in Chinese contexts. Particularly, the included studies have several limitations in study designs, sampling methods, and outcome measurements. First, majority studies included were cross-sectional in design, limiting the ability to draw conclusions about the direction of causality. More longitudinal studies are needed to examine causality between potential correlates and youth depressive symptoms, due to potential correlates could be predictors and consequences of depressive symptoms among youth (e.g., poor academic achievement). Second, most samples suffer from the lacking of representativeness, which in turn severely restricts the generalize ability of the findings. Majority studies are confined to urban areas, leaving youth in deprived rural areas unstudied, where majority youth population reside in Chinese contexts. Meanwhile, overdependence on convenience samples can be problematic. Third, though the prevalence has been examined widely in the selected studies, only two studies based on Taiwan employed culture-relevant items (Lin et al., 2012;. As the great disparity between Western and Chinese culture, it is possible that the reliable and valid Western measurements employed in these studies might not be reliable and valid for Chinese children and adolescents. If the indigenous measurements have been developed and applied in Chinese contexts, the examination of the prevalence of youth depressive symptoms there might be more accurate. For example, among Western-based measurements, more attention placed on affective and existential symptoms (e.g., depressive mood, helplessness, hopelessness), and put insufficient emphasis upon somatic symptoms (e.g., sleep problems, loss of appetite) through which Chinese populations are more likely to experience emotional dysfunction. The qualitative effort would be great to develop measurements specific for youth from different cultural background.

The current review also revealed that there is comparatively more emphasis on individual deficits rather than system deficits in examining ecological risk factors. There are several possible explanations for this observation. First, influenced by Confucian culture existing for thousand years and political movements in the passing century, individuals accustom to blame efforts will help youth, parents, and teachers have a comprehensive understanding of depression, hence delinking associations between biases and depression, "gate keeping" for depressed youth to avoid suicide, and assisting in culturally-informed prevention development.

him/herself if he/she suffers emotional disorders, and do not attribute psychological maladjustment to contextual factors, though contextual factors are more influential than personal factors in some cases (e.g., one-child policy, economic restructure, and unsafe blood collection procedures). Second, human rights, politics, and religion were not open to discussing in mainland China. Although censorship is decreasing in recent years, social researchers still avoid certain areas to discuss even they are important to examine the research questions.

Looking into the future, researchers in the field of child and adolescent mental wellbeing should focus on the following areas. First, we should rethink about the importance of youth mental health and not mistakenly categorize emotional disorders into delinquent behaviors. Chinese youth are not immune to psychological malfunctioning and problem behaviors might be one of the manifestations of depressive symptoms in Chinese contexts. For example, youth internet addiction was primarily treated as delinquent behaviors until recent research found depressive symptoms caused internet addiction (Ko, Yen, Chen, Yeh, & Yen, 2009).

Second, given the extent of impairment related to youth depressive symptoms, identifying protective factors is critical. Although important gains have been made in identifying factors that place youth at risk for depressive symptoms in the current review, much less progress has been made in identifying protective factors. Child and adolescent development is the dynamic interplay between risk and protective factors whereby risk factors predispose individuals to negative developmental outcomes, and protective factors increase resiliency. Although some youth residing in disadvantaged environments seem to do less well, many children and adolescents are resilient and doing well. As such, the effort spending on identifying protective factors is greatly needed.

The third task that youth depression researchers should undertake is to develop preventive programs for Chinese youth. The fact that youth depressive symptoms are present and prevailing in Chinese contexts, researchers should devote to design and implement guidelines to prevent sub threshold depression. There is a need to educate youth, their parents/caregivers, and teachers on youth mood disorders, including onset and course, co-morbidity and impairment, ecological risk factors, and devastating effects on the lives of children and adolescents. These