Cohort survey of college students’ eating attitudes: interventions for depressive symptoms and stress coping were key factors for preventing bulimia in a subthreshold group

Eating disorders are serious illnesses that can be difficult to treat [1]. Many serious problems are associated with eating disorders [2, 3], such as 1) significant mortality rates [4], 2) suicidal behavior [5, 6], 3) high medical costs [7], 4) high rates of comorbidity [8], and 5) strong associations with childhood trauma, such as abuse. Furthermore, long-term treatment for eating disorders is often required, and many prolonged cases have been observed. Eating disorders often develop in adolescence, resulting in a loss of important time for adolescents to make career decisions and prepare for an active role in society. Therefore, strategies that prevent eating disorders and early interventions are important. In particular, bulimia nervosa (BN) is highly comorbid with other conditions, such as depression, impulsive behavioral problems, and suicide [4]. Early intervention, particularly for BN, is therefore an important task to be addressed. However, clear answers as to when and how to provide early interventions are still unavailable.

The aim of this study was to examine the necessity of early intervention by investigating how the eating attitudes of college students change and the relation between bulimic symptoms and depressive symptoms or stress coping. We chose college students as the subjects, because it has been reported that the onset of both anorexia nervosa (AN) and BN increases from adolescence through the college period [9, 10]. We focused on students who showed abnormal eating behaviors, particularly after entrance to college. In Japan, students in college may experience a mental health crisis [11, 12]. In late adolescence through young adulthood, youth are expected to rapidly form their identities and are exposed to psychosocial risk factors such as academic stress and relationship troubles, which are associated with psychiatric difficulties [13].

Regarding eating disorders, the first year of college has been suggested as a critical time period for the development of disordered eating [14, 15]. Many reports suggest that effective prevention, identification, and treatment services are needed to address the observed increase in the incidence of eating disorders on campus [16‐19]. As a result, the risk of eating disorders is thought to be increased in college students.

Although AN may be suspected due to low body weight, BN does not result in low body weight and thus cannot be easily determined based on an outward physical manifestation. Therefore, it is important to study intervention methods aimed at targeting the early stage of bulimia. In the present study, we studied eating attitudes at two time points, university entrance and the fourth year, and observed how college students’ eating attitudes changed over time. Some research reported that subthreshold cases often progress to threshold cases, and early intervention has been shown to prevent severe illness [20‐22]. Interventions for depression are important because individuals with eating disorders are often suicidal. In addition, we previously reported on the relationships between eating disorders, depressive symptoms and stress coping, and the results showed improvements following treatment [23, 24]. We hypothesized that partial symptoms of bulimia would appear early and would be related to depressive symptoms; in addition, this tendency would be noticeable in female students.

Because this study is not anonymous, we were able to observe the changes of individual students, which represents a new point that is not found in previous reports.

In the present study, we investigated individual changes in students’ scores from Time-1 to Time-2, as well as overall changes in eating attitudes. This strategy is different from previous studies. A greater number of individuals displayed an increased risk of developing bulimia than the number of individuals displaying a decreased risk. In addition, the risk of bulimia did not improve in 3/4 of the individuals, particularly the females in the subthreshold group. This result suggests that preventive intervention is necessary for the subthreshold group. A 5-year longitudinal population-based study reported that one-third of adolescents were asymptomatic at baseline and that more than half of the individuals who were symptomatic at baseline showed symptoms 5 years later [29]. Similar to previous reports, the present study also revealed that problematic eating behaviors persisted once they appeared, and thus early intervention is needed.

The BITE scores increased for both males and females from Time-1 to Time-2, suggesting that bulimic symptoms might worsen during college years. In addition, the EAT-26 score was significantly decreased for males and tended to decrease for females; therefore, in some cases, bulimic symptoms may have developed from anorexic symptoms. Thus, early detection of an increase in the bulimic symptoms of college students is important.

Another 8-year prospective community study of young women found that the onset of BN was 16–20 years old [9]. Based on these survey results, early screening and intervention may be appropriate for college students. According to several studies of college students, the prevalence of eating disorders is high, ranging from 11 to 17% in female students and 4% in male students. A study of 12 colleges in the United States [30] reported that binge eating was observed in 49% of females and 30% of males. In Japan, many college students are estimated to present bulimic symptoms. The increase in the already high eating disorder rate on college campuses combined with academic and social stress, transitional and environmental factors, and a lack of campus resources creates a combination of factors that may result in crisis [31]. In addition, the university is the last educational institution attended before college students enter society; therefore, it is reasonable to screen college students to enable clinicians to provide early intervention for high-risk students.

In terms of an effective early intervention, the developmental pathways of eating disorders should be explored [31]. In the present study, we focused on the association with depressive symptoms. We compared a group showing improved BITE scores from Time-1 to Time-2 with a group whose scores worsened to examine the relation between changes in BITE scores and depressive symptoms. Bulimic symptoms and depressive symptoms worsened in both males and females. The causal risk factors for eating disorder symptoms are important [32‐35]. As shown in the study by Pearson et al. [36], adolescents with depressive symptoms that were one standard deviation higher than their peers had a 53% higher risk of transitioning from the asymptomatic group to the disordered group. Depressive symptoms are a risk factor for eating disorders and are specifically associated with worsening bulimic symptoms. The lifetime prevalence of suicidal ideation among patients with BN has been reported to be 15–23% [37] and 26–38% [38]. According to Corcos, patients with BN who had a history of suicide attempts exhibited a higher prevalence of depressive disorders than patients with BN without a suicide attempt history [39]. In the study by Preti, individuals with BN were seven times more likely to die by suicide than females aged 15–34 in the general population [40]. In the early intervention for BN, interventions for both eating behaviors and depressive symptoms may be the key to preventing severe eating disorders and suicide.

In addition, we considered that a focus on the subthreshold group would be important for early intervention; therefore, we compared the subthreshold group with the healthy group. BDI-II scores were significantly higher for both males and females in the subthreshold group than in the healthy group. We cannot conclude that intervention for depressive symptoms would be effective at preventing BN based only on this result, but interventions targeting both eating behaviors and depressive symptoms may be more effective.

Furthermore, the tendency for female students in the subthreshold group to emotionally respond to stress was related to disordered eating. Therefore, stress coping interventions may be important for the prevention of disordered eating. There have been reports on eating disorders and stress coping [41‐45]. Some reports have examined the relation between eating disorders and avoidance coping behaviors [42], particularly AN [43]. On the other hand, patients with BN display a significantly increased use of emotional coping behaviors [34, 45]. We speculate that AN may be associated with avoidance coping behaviors and BN with emotional coping behaviors. In terms of early intervention, cognitive behavioral approaches designed to improve coping skills and resolve problems objectively during stressful situations are thought to be effective.

Previous studies have reported that sexual minorities [46] and athletes [47, 48] are at a high risk of developing BN. In the present study, we did not investigate sexual minorities. In terms of athletes, we did not observe a difference in the students’ departments (major). In addition, the student’s living environment (living with family or living alone) can also be related to BN, but we did not consider this factor in the present study.

Depressive symptoms are a risk factor for eating disorders and are specifically associated with worsening bulimic symptoms. Interventions for depressive symptoms and stress coping may be key factors in early intervention for bulimia. Furthermore, the results suggest that early intervention may be necessary for both the subthreshold and clinical groups.