Depression and academic performance A number of studies have shown that symptoms of depression affect student’s performance and achievement at university, college and school (Stark & Brookman, 1994, cited in Shamsuddin et al., 2013). Findings in this area indicate that academic tasks cause a high risk of mental health problems, especially depression in students (Ibrahim et al., 2013; Sharif et al., 2011). A Turkish study found that depressed students have a poorer academic performance compared to students who do not report symptoms of depression (Bostanci et al., 2005). Owens, Stevenson, Hadwin and Norgate (2012), on anxiety and depression on academic performance among students in the UK, found that depression has a negative relationship with academic performance. They investigated that a higher level of depression was associated with poorer academic performance. Another study about the impact of depression on academic performance among undergraduate students mentioned that depression has a strong and a negative relationship with academic performance. This robust and risky relationship includes a number of negative consequences for students (Hysenbagasi et al., 2005). Similarly, a recent study by Ceyhan et al. (2009), on depression in university students, found that students who have a poor academic achievement demonstrated considerably greater depressive symptoms compared to students who indicated a high level of academic achievement. It also should be considered that student’s depression is a serious risk to academic impairment, which continues and is increased by depression during academic life (Heiligenstien & Guenther, 1996). Another notable consequence of depression is that students who display a depressed mood are likely to lose academic motivation and academic activity. Depressed students also have many difficulties in academic tasks at university (Khawaja & Bryden, 2008). In qualitative research by Anderson (2003), students mentioned that depression is one of the main causes of their academic problems, including academic performance. Overall, studies in this area reported a negative relationship between academic achievement or performance and depression. It is obvious that during their academic life, students have many goals, obligations and expectations for the future. If some students fail to achieve their goals, meet expectations or responsibilities, they are at a higher risk of suffering from depression and other psychological and mental problems (Patchett, 2005, cited in Ceyhan et al., 2009). For this reason it is assumed that poor academic success or performance is one of the main causes of depression among students (Baker & Siryk, 1984). However, it is not easy to decide if depression is a consequence of a low level of academic achievement or vice versa. Depression can have a negative impact on cognitive functioning and this can impact negatively on academic performance or achievement (Turner, Thompson, Huber & Arif, 2012). Common causes of depression among students The distinct causes of depression among students have not been investigated, particularly in the previous studies. It is important to remember that the above studies have shown high rates in the prevalence of depression (from 5% to 30%) in students across the world (Ibrahim & Kelly, 2011). The large variation in this percentage has not been mentioned, but it might be said that this is because the studies were performed in different populations, societies and cultural backgrounds (Bayram & Bilgel, 2008; Dahlin at al., 2005). Another factor in this large variation may be due to the studies using different methodologies or tools to diagnose this problem among students (Ovuga, Boardman & Wasserman, 2006). In the literature, studies have determined different factors of depression among students, but there are some common causes of depression among students. This part of the review will look at common factors in many of the studies about the prevalence of depression in students during their academic career. The first serious cause associated with the depression among students is socio-economic status. A limited number of studies have investigated the effect of socio-economic factors on depression in the student population (Ibrahim et al., 2013). Student’s socio-economic level has been shown to play a significant role in the symptoms of depression in students (Sareen, Afifi, McMillan & Asmundson, 2001). A large cross-national (from 23 countries) study (Steptoe, Tsuda, Tanaka & Wardle, 2007) on the relationship between symptoms of depression and socio-economic background of university students showed that family and personal income level, parental education and family wealth, contributed to depression in students. Similarly, data from an analysis of Egyptian studies on the relationship between socio-economic status and depression among undergraduate students found that socio-economic background associated negatively with symptoms of depression in students. This study concluded that students from families with a low level of income and parental occupation have a tendency towards depression (Ibrahim et al., 2013). More notably, the financial problems of students and their families have a negative impact on depression in students (Andrews and & Wilding, 2004). The study showed that students originally from the countryside recorded higher levels of depression than students who live in cities (Bayram & Bilgel, 2008). Shamsuddin and his colleagues (2013) reported that this might be due to an economic situation where families in rural areas often have a lower economic status. Moreover, it might be explained that some students from rural areas move away and leave their families while at university, and this might cause some difficulties for some students. Studies also show that students who are from a higher socio-economic position such as a high level of social class, an educated background and economic situation, are more likely to have a sense of control. This sense of control can provide students better protection against mental health problems, namely depression, associated with moving to a university environment (Lanchman & Weaver, 1998). Additionally, the educational level of student’s parents could play role in depression associated with the university environment of students. For example, Ibrahim et al. (2013) found that students with less educated family are 50% to 60% more likely to suffer from problems of depression compared to highly educated families (father and mother). It is also reported that the father’s occupation has an effect on depression in students. For instance, Ibrahim and Kelly (2011) found that students whose father had a professional job are 60% more likely to obtain depressive disorders compared to students whose father was an unskilled worker. The second most common cause, reported as a serious factor for the rate of depression in students, is living away from home or transition to new environment, such as university and college. For some students, separation from home or family might cause psychological distress, especially depression. This is due to problems and difficulties associated with living in a new and different environment at university or college without social support (Asyan, Thompson & Hamarat, 2001). It was also found that students who live at home with their families are less likely to be affected by depression because their families provide more support and enhanced protection against academic stress (Christie, Munro & Retting, 2002). It is pointed out that although it is less costly for students to share accommodation, and gives more social advantages, those share house students may be dissatisfied with their environment and housemates, and there are more opportunities to be diverted away from their studies. It is believed that this dissatisfaction leads to increased psychological distress such as depression and stress. Another problem with accommodation is that students who live alone may face problems without social support, especially international students. A study by Haldorsen et al. (2014) found that students dealing with social problems and psychological distress have a higher rate of the symptoms of depression compared to students living with their family. The above evidence shows that students, who live with their family and partners and have the social support to deal with their problems, have a better chance of living without depression while at university and college. Although the transition to college and university is a successful step, and it is a good opportunity for students to have a better future, in poor countries it might cause some students who move to university some social and psychological problems, including depression. For example, Adewuya and his colleagues (2006) explained that symptoms of depression in Nigerian students could be caused by poor academic conditions, overcrowded classrooms, a poor quality of accommodation, and a lack of learning materials and equipment. An important finding mentioned in the recent study of Haldorsen et al. (2014) found that the stress factors of students have a significant association with symptoms of depression. In the previous study Haldorsen et al. (2014) concluded that increased stress in students led to raised symptoms of depression. Similarly, Bayram and Bilgel (2008) emphasized the same relationship between depression, stress and anxiety. The third main cause of depression among students is study satisfaction. That means that students who are not satisfied with their course of study have greater rate of depression than students who are satisfied (Bayram & Bilgel, 2008). A possible interpretation for this finding may be the student’s lack of interest and motivation in their major, because on some occasions the student’s parents choose the subject for study (Chen et al., 2013). Another recent study concluded that students who are content with their education are less likely to suffer from depression and anxiety (Dahlin et al., 2005). Interestingly, another cause of depression in school and college age students is body size or body weight. Depression related to body size has been investigated by a number of studies (Granberg, Simons, Gibbons & Melby, 2008). There is evidence of no relationship between body weight and psychological distress in adult students. For example, a study by Granberg and his colleagues (2008) on the relationship between depression and body size among 343 African-American middle-school females, found no link between symptoms of depression and weight. That means that an unhealthy weight did not cause more symptoms of depression among those female students. The authors explained that this finding may be due to the belief that African-American girls are more likely to overestimate their weight. On the other hand, an American study found that overweight students in a middle school in Texas were more depressed compared to students of a normal weight (Schiefelbein, Mirchandani, George, Castrucci & Hoelscher, 2010). This finding is also supported by another study from the United States from 1980 to 2002. It indicated a high rate of depression in overweight and obese teenagers and children, and this high rate continues to increase (Ogden et al., 2006). Additionally, some studies highlighted that obesity or being overweight has a positive relationship with depression in adolescents in the United States (Jorm et al., 2003). Jorm and his colleagues also showed that these studies also looked at gender differences in overweight adults. They found that female adults in the United States were more depressed compared to male adults. A possible interpretation of this phenomenon may refer to findings that boys are less likely to overestimate their weight, and think they do not weigh enough, whereas most girls overestimate their weight (Strauss, 1999). From the above evidence, it might be true that adults and younger students who have a healthy or normal weight are less depressed than adult students who have an unhealthy or abnormal weight. Indeed, adult female students are more likely to show symptoms of depression. Furthermore, Ceyhan and Kurtyilmaz (2009) found that students who are satisfied with their body shape are less depressed than students who are displeased with their body shape.