Suicidal ideation can be defined as “thoughts of engaging in behaviour intended to end one’s life” and is an important indicator of both mental health vulnerability and the risk of engaging in suicide attempts[2, 3]. It is especially common during adolescence, with prevalence increasing from age 12 and peaking by age 16, remaining elevated into the early twenties.
School classrooms represent an important social context for adolescents. Here, students spend a large portion of their waking hours with a group of classmates who they had no opportunity of choosing themselves and who they are required to interact with. The continuous interaction among the students in each class creates unique psychosocial environments which vary in factors such as shared beliefs, emotions, habits and peer pressure[4, 5]. These environments can influence the mental health of students in both positive and negative ways. As a consequence, some school classes are likely to have more students with suicidal ideation compared to others.
It has also been suggested that suicidal ideation may cluster within schools due to suicidal behaviour transferring between individuals as a result of interpersonal interactions with other students who are suicidal. That is, the probability of suicidal ideation could be higher in contexts where there are students with thoughts of taking their own lives who then communicated this ideation outward. If this is the case, then it follows that students who originally are at a low risk for experiencing suicidal ideation may be at higher risk if they have extensive contact with such at-risk individuals.
Multilevel analyses are particularly effective in examining the importance of the school class context because they enable the variation between individuals and groups to be assessed separately. However, multilevel studies investigating the relationship between school context and suicidal ideation are rare[6, 8, 9]. In the only known study reporting between-school variation in suicidal behaviour, Young et al. found that a small percentage of the variation in attempted suicide (1%), suicide risk (1.3%) and self-harm (1.6%) could be attributed to the school level. The extent to which suicidal ideation may be related to the school classroom context has not been previously examined through the use of multilevel analyses. Research on other mental health outcomes does, however, suggest that the differences between school classrooms are greater than the differences between schools[10–12].
It can be argued that the influence of the social environment on one’s mental health, as well as transference of suicidal ideation, is related to the gender and socioeconomic composition within school classes. Both socioeconomic status and gender are background characteristics often found to be associated with suicidal ideation and mental health. For adolescents, a higher level of parental socioeconomic status is usually associated with fewer mental health problems[13, 14], while girls tend to have a higher prevalence of suicidal ideation compared to boys[3, 15–19]. If the probability of having suicidal ideation increases as a result of extensive contact with at-risk individuals, then the probability of suicidal ideation should be higher in school classes containing a greater proportion of girls or of students with low socioeconomic background.
Moreover, research has shown that a school’s culture regarding academic achievement can vary greatly depending on the students’ socioeconomic background. Likewise, several studies have suggested that the socioeconomic composition of the school context is associated with mental health status, over and above individual socioeconomic characteristics[6, 20–22]. The majority of these studies have found the level of socioeconomic status to be positively related to reports of better mental health, but as with the school context in general, studies specifically examining the relationship between socioeconomic composition of school classes and mental health are scarce. It is, however, likely that school classes, in the same way as schools themselves, will manufacture unique social environments, suggesting that there may be positive effects of a higher average level of socioeconomic background at the class level as well.
Similarly, the influence of one’s psychosocial environment may also depend upon that environment’s gender composition. In a review by Belfi et al., the authors conclude that students in single-sex schools have higher levels of well-being compared to students in mixed schools. This is, however, a gender-specific effect because the relationship has only been documented among girls. Multilevel research analysing the association between classroom gender composition and student mental health is rare, and the few studies testing this relationship have not found significant effects.
In this study, suicidal ideation among a population of Norwegian adolescents is examined in relation to school class composition. Suicidal behaviour is a common problem among Norwegian adolescents, and studies on suicidal attempts and self-harm have reported prevalence rates ranging from 3.0 to 8.2 percent. An additional study examining Norwegian conscripts reported a 21.7 percent prevalence rate of life-time suicidal ideation, while a second study of adolescents in their last year of upper secondary education (18–19 years) found the prevalence of individuals having suicidal ideation during the last week to be 10.9 percent.
To examine the association between suicidal ideation and school class composition, the following two research questions were formulated:
To what degree can variation in suicidal ideation be attributed to differences between school classes?
Is there an association between suicidal ideation and school class composition in regards to student gender and parental education?