Bullying, health complaints, and self-rated health among school-aged children and adolescents.

Bullying has numerous detrimental effects, including poorer emotional, social, and physical health both during individual bullying events and in the periods between them.[1] Bullying can also have long-term negative effects, such as a pessimistic future orientation, maladaptation to adult roles, trouble forming lasting relationships, and suicide ideation and attempts later in life.[2-4] Bullying can negatively affect bullies as well as victims of bullying (including bully–victims, that is, individuals who are the victims of bullying and bullies themselves) in manifold ways.[5] Researchers have noted that bully–victims tend to view their overall health more negatively than do others and have higher levels of internal difficulties, such as depressive symptoms and suicidal thoughts.[5-7] Therefore, in the present study, we focused on illuminating the health implications of being bullied.

According to Inchley et al.,[8] 11% of children aged 11 to 15 years claim to have been bullied at least two times per month within the previous 2 months, based on data collected by the international research network Health Behavior in School-aged Children (HBSC). In Iceland, the self-reported frequency of bullying victimization at least two times per month was much lower, at 5.5%.[9] The Icelandic study also found that age and sex were important factors to consider when exploring the prevalence of bullying among school-aged children and adolescents; however, questions remain regarding the specific influences of age and sex on the effects of bullying.

Bullying is closely linked to depression,[10,11] although the relationship is not completely understood. A longitudinal study of Finnish adolescents revealed that bullying victimization predicted depression among boys whereas among girls, depression predicted victimization.[10] Ivarsson, Broberg, Arvidsson, and Gillberg[12] showed that a substantial proportion of adolescents who were being bullied had psychiatric warning signs, such as depressive and internalizing symptoms, and showed poorer social functioning. Fekkes, Pijpers, Fredriks, Vogels, and Verloove-Vanhorick[13] showed that bullying victims had a higher risk of developing psychosomatic and psychosocial problems compared with children who were not bullied. Thus, some problems appear to follow bullying victimization whereas other problems seem to precede it.

Sleeping difficulties are also associated with bullying victimization. Difficulties falling asleep might result from thoughts about being bullied. Furthermore, with the extensive use of mobile phones among children and adolescents, there are plenty of opportunities for bullies to continue their harassment, even at night. Indeed, there is now a high degree of overlap between children who are cyberbullied and those bullied in more traditional ways.[14] Recent findings show that many victims of bullying have significantly greater subjective sleep disturbances than do the bullies themselves and those who are not involved in any bullying activity.[15] Furthermore, a lack of sleep and stress are associated with dizziness among adolescents,[16] rendering these variables important to consider in bullying research.

Self-rated health is a subjective indicator of general health. Studies have shown that this measure is an important index of future morbidity and mortality.[17,18] Breidablik, Meland, and Lydersen[19] noted that adolescents’ self-rated health is influenced by a number of different factors, such as medical, psychological, socioenvironmental, and behavioral factors, as well as contextual factors concerning the family, peers, school, and culture. Consequently, as a contextual factor associated with peer relationships, bullying is likely to affect self-rated health.

Given the sometimes severe problems surrounding bullying and the number of victims, it is important to obtain a better understanding of this problem. Therefore, the aim of this study was to examine the associations of depression, difficulties falling asleep, dizziness, and self-rated health with bullying victimization among school-aged children of both sexes and different age groups in Iceland.

Methods

Data

The study used the Icelandic dataset of the World Health Organization’s international research network, the HBSC.[20] The HBSC research network is a large-scale, cross-national study of 11-, 13-, and 15-year-olds carried out every 4 years in 43 countries across Europe and North America. The focus of the survey is on health behaviors and their determinants and consequences.[8]

Sample

The sample included all students throughout Iceland in grades 6, 8, and 10 who were attending school on the day of administration of the HBSC’s standardized, anonymous questionnaire.

Teachers distributed the questionnaire between November 2013 and January 2014. A single school lesson (45 minutes) was dedicated to completing the survey.

Measures

The HBSC survey comprises a standard mandatory questionnaire, to which individual countries can add optional items that examine a topic in more depth.[8]

Bullying

The question on bullying was preceded by the following explanation: “We say that a student is being bullied when another student, or a group of students, says or does nasty and unpleasant things to him or her. Bullying is also when a student is teased repeatedly in a way that he or she does not like, or when he or she is deliberately left out of things. However, bullying is not when two students of about the same strength or power argue or fight. Bullying is also not when a student is teased in a friendly and playful way.” The question on bullying was then presented, as follows: “How often have you been bullied in school during the past month?” Students were given five response options, ranging from never to several times a week. In this study, the responses were dichotomized, such that never been bullied or bullied a maximum of two times in the previous month were coded as 0, and all other options (up to several times a week) were coded as 1.

Self-rated health

Self-rated health is a subjective indicator of general health. The students were asked “Would you say your health is … ?” The response options were excellent, good, fair, and poor. Responses were dichotomized, such that excellent and good were coded 0, and fair and poor were coded 1.

Health complaints

The students were asked how often they had experienced the following symptoms in the previous 6 months: feeling depressed, difficulties falling asleep, and feeling dizzy. The response options for each symptom ranged from about every day to rarely or never. The answers were dichotomized, such that having the health complaint less than once per week was coded as 0, and having the health complaint once a week or more was coded as 1.

Analysis

We calculated descriptive statistics for bullying, health complaints, and self-reported health, including frequencies and percentages. The associations between bullying and self-reported health and health complaints were analyzed using chi-squared tests and logistic regression analysis.[21] The level of significance was set at 5%. The statistical analysis was performed using IBM SPSS Statistics version 21 (IBM Corp., Armonk, NY, USA).

Results

A total of 161 schools with 11,018 students participated in this study. The response rate was 84% because some students (n = 628) chose not to answer the questions on bullying. Therefore, the sample consisted of 10,390 students, 50% of which were female; 32.1% of participants were 6th graders (mean age 11 years, SD = .067), 34.9% were 8th graders (mean age 12.99 years, SD = .098), and 33.0% were 10th graders (mean age 15 years, SD = .03). Comparisons between the study respondents and the total population showed very similar sex, age, and residential compositions (differences were between 0.5 and 1.0%).

As shown in Table 1, respondents of both sexes who had been bullied were more likely than non-bullied students to have feelings of depression, difficulties falling asleep, dizziness, and poorer self-rated health (p < .001).

Table 1.

Percentages of non-bullied and bullied girls and boys reporting feelings of depression, sleep difficulties, dizziness, and general health complaints (N = 10,626).

	Total		Girls		Boys
	Non-bullied(n = 10,041)	Bullied (n = 585)	Non-bullied(n = 4914)	Bullied (n = 297)	Non-bullied (n = 4942)	Bullied (n = 270)
Weekly complaints
Feeling depressed	31.5%	72.3%*	39.4%	80.1%*	23.5%	65.9%*
Difficulty falling asleep	40.2%	66.7%*	42.9%	70.7%*	37.5%	62.6%*
Dizziness	24.3%	50.6%*	27.8%	58.6%*	20.6%	41.9%*
Health
Low self-rated health	16.3%	35.4%*	17.0%	40.1%*	15.4%	30.4%*

*Chi-square value showing significant differences between the non-bullied and bullied groups (p < .001).

Notably, reported feelings of depression were high for both bullied (72.3%) and non-bullied (31.5%) children and adolescents. The risk ratios for having depressive symptoms when bullied were 2.80 for boys and 2.03 for girls whereas those for low self-rated health were 1.97 for boys and 2.36 for girls.

As shown in Table 2, there were also significant differences in the prevalence of health complaints between non-bullied and bullied students within each of the three age groups (p < .001).

Table 2.

Prevalence of health complaints among non-bullied and bullied students aged 11, 13, and 15 years (N = 10,334).

	11-year-olds		13-year-olds		15-year-olds
	Non-bullied (n = 3072)	Bullied(n = 232)	Non-bullied(n = 3448)	Bullied(n = 201)	Non-bullied (n = 3254)	Bullied (n = 127)
Weekly complaints
Feeling depressed	27.5%	70.3%*	29.1%	77.1%*	37.5%	74.0%*
Difficulty falling asleep	39.6%	69.8%*	40.7%	63.7%*	40.2%	68.5%*
Dizziness	18.8%	46.6%*	24.8%	53.2%*	28.5%	55.9%*
Health
Low self-rated health	10.3%	28.0%*	17.1%	39.3%*	20.6%	44.1%*

*Chi-square value showing significant differences between non-bullied and bullied groups (p < .001).

Multiple logistic regression analysis (Table 3) revealed that feelings of depression, difficulties falling asleep, dizziness, and low self-reported health were all predicted by bullying victimization when controlling for age and sex. We also tested the interactions between bullying and sex and between bullying and age. However, the interactions were not significant, indicating that the effects of bullying on health complaints and self-rated health (in terms of odds ratios) appear to be the same, regardless of age and sex.

Table 3.

Logistic regression analysis of factors associated with bullying victimization (N = 10,626).

	Odds ratio
Depressive symptoms	3.84* [3.13, 4.71]
Low self-rated health	1.63* [1.35, 2.0]
Dizziness	1.62* [1.34, 1.96]
Sleeping difficulties	1.44* [1.18, 1.76]
Hosmer–Lemeshow test p = .05
Nagelkerke’s R2 = .126

Note: Numbers in brackets are 95% confidence intervals for odds ratios.

*p = < .001.

Discussion

The aim of the present study was to examine whether bullying victimization was associated with health complaints and self-rated health among children and adolescents in Iceland. The results indicated that victims of bullying are more likely to have compromised health than are children who are not bullied, although there were rather high levels of depression among non-bullied children and adolescents as well. These findings are in line with those of previous studies[6,7,13] showing that individuals who experience bullying have a higher risk of developing psychosomatic and psychosocial problems. Similar to bullying, ostracism—exclusion from a group—has been found to be highly stressful and can lead to the development of depression.[22] However, it should be noted that depression has also been shown to affect bullying, such as by impairing a person’s social skills (thereby making them more prone to victimization) or distorting their experiences of social interactions (e.g., perceiving aggression where there is none).[15]

Bullying is a serious public health concern and one of the most common forms of victimization among children and adolescents.[23,24] Whereas some studies have suggested that the incidence of bullying is decreasing slightly, [25] it is noteworthy that one-third of children surveyed report occasional victimization, and one in eight children report chronic victimization.[26] When exploring the number of children experiencing bullying victimization, it is important to acknowledge the myriad definitions and interpretations of the term bullying. According to the HBSC, an individual is being bullied when “others say or do nasty and unpleasant things to him or her, tease him or her repeatedly in a way he or she does not like, or when he or she is deliberately left out of things”.[8] This definition is broader than that suggested by Olweus,[26,27] who proposes that bullying has three pillars: (a) hurtful behavior that is (b) repeated and (c) difficult for the target to defend against owing to an imbalance of power. Yet another definition associates the term bullying with severe physical aggression.[25] These differing interpretations might be a reason that the prevalence of bullying victimization among children differs across studies.

Although there were a substantial number of bullied children and adolescents in our population who reported feelings of depression, we should also take note of the remaining 20% of girls and 34% of boys who reported being bullied but who did not report having depressive symptoms. Few studies have focused on victims of bullying who function “better than expected” and who are therefore defined as “resilient”.[28] Some studies suggest that children and adolescents with more than three friends and who play sports tend to be less victimized by bullying.[14] Furthermore, bullied children and adolescents who report low levels of depressive symptoms tend to be male, have high self-esteem, feel less socially alienated, experience lower levels of conflict with parents, and are not victimized by siblings.[28] However, that being male is considered a resilience factor does not accord with the findings in this study, where sex differences in the effects of bullying were small and not significant. This differing result is a telling example of the difficulties in researching bullying.

In this study, about 70% of bullied girls and 63% of bullied boys experienced difficulties falling asleep, compared with 40% among non-bullied students of both sexes. Studies have shown that difficulty falling asleep generally affects around 25% of young people;[29] independent of the cause, this predicts sleep difficulties later in life.[30] Difficulties in falling asleep partly overlap with depressive symptoms but are also related to the bullying situation itself.[15] Dizziness was experienced by a quarter of adolescents in the present study; among those who were bullied, about 50% reported this complaint.

Regression analysis showed that bullied children and adolescents have higher odds of feeling depressed, experiencing difficulties falling asleep, and feeling dizzy. Because stress is a strong risk factor for dizziness[16] and being bullied is a stressful experience, it might be productive to further explore the links between stress, dizziness, and bullying.

Our results showed that bullying also predicted poor self-rated health. The implications of this finding are somewhat complicated because the interpretation of self-reported health is as complex as that of bullying. Nevertheless, given that bullying victimization is accompanied by poorer health and higher rates of depressive symptoms, this result should be considered a definite indicator of the need for preventive action.

As the repercussions of bullying victimization are often long-lasting,[31,32] it is important to make systematic efforts toward its curtailment. Adults working with children, such as teachers, social workers, and medical personnel, must focus not only on overt verbal, social, and physical forms of bullying but also its internal ramifications, such as depressive symptoms, sleeping difficulties, dizziness, and poor overall health.

Strengths, limitations, and implications

The strengths of this study are the high response rate and representativeness of the sample. Furthermore, we used a standardized anonymous questionnaire, which reduces response bias stemming from social desirability and sensitive items.

Bullying is defined and interpreted in many different ways in different studies, which limits our ability to compare our findings with those of other studies. Indeed, the complexity of the term could account for unexplained variations within and between studies; furthermore, the cross-sectional design precludes definite conclusions about causality. Finally, although the response rate was high, victims of bullying have higher rates of absenteeism than their peers,[33] which might lead to underestimation of the scope of the problem. Another school-related issue is the focus of bullying in school settings whereas cyberbullying can take place anywhere.

Bullying among school-aged children and adolescents is a major public health problem given its scope and often long-lasting effects [e.g., 3, 4]. Systematic interventions are needed to address this problem, such as parent information meetings, firm discipline, and adult supervision at school, as discussed in a review by Ttofi and Farrington.[34] Other intervention programs directly aimed at heath complaints in school-aged children, such as the Depression in Swedish Adolescents program aimed at reducing depression,[35] should also be considered. Moreover, further research on resilience among those who are bullied is necessary.

List of abbreviations

HBSC: Health Behavior in School Children.

WHO: World Health Organization.