March 6, 2008 — In an Australian, population-based, longitudinal cohort study, the incidence of bulimic, but not anorexia nervosa, syndromes in teenaged girls was linked to childhood sexual abuse.

The incidence of bulimia was 4.9 times higher among the study participants who reported having multiple episodes of childhood sexual abuse vs those who reported having no such history, after adjustment for factors such as parental divorce and educational level.

The study, with lead author Lena Sanci, MBBS, PhD, at the University of Melbourne in Melbourne, Victoria, Australia, is published in the March issue of the Archives of Pediatrics & Adolescent Medicine.

“This paper takes a step further in confirming suspicions that clinicians have long had that sexual abuse is common in young women with bulimia,” study author George Patton, MBBS, MD, at the University of Melbourne, told Medscape Psychiatry. Childhood sexual abuse was reported by 1 in 5 young women in this Australian community; however, it was reported by 1 in 2 young women with bulimia, and the numbers may well be even higher in a clinical setting, he noted.

“So the message is one of sensitivity to the possibility of past sexual abuse in young bulimic patients,” he said.

Previous studies that examined the relationship between childhood sexual abuse and subsequent eating disorders have reported inconsistent findings, likely because of methodologic weaknesses, the group writes. Studies should include data from ages 14 to 16 years, the time of peak onset of anorexia nervosa, and the time that bulimia usually starts, they add.

The group performed a population-based, longitudinal cohort study using data from 1992 to 2003 from the Victorian Adolescent Health Cohort.

This cohort was a sample of adolescents selected at random from 2 classrooms at each of 44 schools in Victoria. The teens from 1 classroom entered the study in grade 9, and those from the second classroom entered the study in grade 10. The teens were surveyed 4 times at 6-month intervals and then were surveyed twice when they were young adults.

There was an insufficient number of boys with an eating disorder (n = 6), so this study was restricted to 999 girls and young women observed from a mean age of 14.9 years at study entry.

The outcome of the study was an incident eating disorder at a mean age of 16.3 to 17.4 years.

The last survey, when the mean age of the young women was 24 years, asked the women to report any sexual abuse before age 16 years.

Because of the low prevalence of the full syndromes of anorexia and bulimia nervosa, partial syndromes were identified as cases.

Patients With Bulimia Often Had History of Sexual Abuse

Of the 999 study participants, 121 (12.1%) women reported 1 incident of sexual abuse with or without physical contact before age 16 years, and 82 (8.2%) women reported 2 or more such incidents. Parental divorce and low educational level were more common in women reporting childhood sexual abuse.

Compared with the women who reported no episodes of sexual abuse before age 16 years, those who reported multiple episodes had a 4.9-fold increased risk for bulimic syndrome. The association persisted after adjustment for precursors of bulimia — recent depression, anxiety, or dieting behavior.

Table. Risk for Incident Bulimia in Adolescence

*Adjusted for age, parental divorce or separation, and parental education.
^†Adjusted for age, parental divorce or separation, parental education, and bulimia precursors — recent anxiety, depression, or dieting behavior.

The researchers did not find an association between childhood sexual abuse and incident adolescent anorexia nervosa.

“We concur with others who conclude there is a link between childhood sexual abuse and eating disorders on the need to consider the possibility of childhood sexual abuse when treatment of eating disorder is complicated and to specifically target the comorbidities of childhood sexual abuse before meaningful treatment of an eating disorder can begin,” they write.

The study suggests that sexual abuse may initiate a pattern of dealing with emotional distress that brings a high likelihood of bulimia, said Dr. Patton.

This study was supported by the National Health and Medical Research Council; the Centre for Excellence in Eating Disorders; and a research grant from beyondblue, the National Depression Initiative. Dr. Patton holds a professorial chair in Adolescent Health Research supported by the Victorian Health Promotion Foundation. One of the other study authors is the recipient of a Victorian Health Promotion Foundation Public Health Fellowship. Two other study authors have obtained funding. The remaining study authors have disclosed no relevant financial relationships.

Arch Pediatr Adolesc Med. 2008;162:261-267.

Clinical Context

Study Highlights

• 1044 girls were randomly selected from a pool of 60,905 students in 44 schools.
• The first class was enrolled at age 14 years in the latter part of ninth grade, and the second class was enrolled 6 months later in the first part of 10th grade (mean age, 14.91 years).
• 1000 (95.8%) girls participated in at least 1 of the first 6 computer-based questionnaires conducted at enrollment and 4 times at 6-month intervals.
• Evaluation 4 times at 6-month interval visits included the Branched Eating Disorders Test to identify new onset of disorders, a 9-item Adolescent Dieting Scale to assess dieting behavior, and the Clinical Interview Schedule to assess depression and anxiety.
• Computer-assisted telephone interviews were done when the participants were ages 20 to 21 years and ages 24 to 25 years (mean age, 24.03 years).
• 824 (82.4%) girls completed the final survey to retrospectively report “no,” “1,” or “2 or more” episodes of sexual abuse that had occurred before age 16 years.
• Reasons for not completing the final interview were refusal, loss to follow-up, and death.
• Data were analyzed for 999 girls from four 6-month intervals and final interviews.
• “Anorexia nervosa syndrome” was defined by at least 2 Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for anorexia nervosa: body mass index (BMI) below the fifth percentile, fear of weight gain despite BMI below the 25th percentile, overconcern with weight and BMI below the 25th percentile, and secondary amenorrhea for 3 or more months.
• “Bulimia nervosa syndrome” was defined by at least 2 Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for bulimia: bingeing, purging, and overconcern with weight.
• 12.1% of the participants reported 1 episode of sexual abuse.
• 8.2% reported 2 or more episodes of sexual abuse.
• Parental divorce was more common if there were 2 or more reports of abuse (32.9%) vs 1 report of abuse (27.3%) vs no report (20.4%).
• Parental incomplete high school education was more common if there were 2 or more reports of abuse (50.0%) vs 1 report of abuse (42.1%) vs no report (34.2%).
• 95 girls had 1 episode of abuse, and 96 had 2 or more episodes without physical contact.
• 96 girls had 1 episode of abuse, and 70 had 2 or more episodes with physical contact.
• 127 (12.7%) girls reported combined abuse with and without physical contact.
• 35 (3.5%) new cases of bulimic syndrome occurred.
• 32 (3.2%) new cases of anorexic syndrome occurred.
• 4 girls had combined anorexia and bulimia nervosa.
• Baseline evaluation identified 19 girls with anorexia nervous and 29 with bulimia nervosa who were not included in analysis.
• Childhood sexual abuse and incidence of anorexic syndrome did not seem to be related.
• After adjustment for background factors, girls who reported 1 episode of sexual abuse vs no abuse had 2.5 times higher incidence of bulimic syndrome, and those who reported 2 or more episodes of sexual abuse vs no abuse had 4.9 times higher incidence of bulimic syndrome.
• Further adjustment for dieting behavior and symptoms of depression and anxiety in the past 6 months slightly, but not significantly, reduced the association between childhood sexual abuse and bulimic syndrome.
• Reports of 2 or more episodes of abuse vs no abuse predicted incident purging (hazard ratio, 4.4).

Pearls for Practice

• The incidence of bulimic symptoms in adolescence is higher in girls who report childhood sexual abuse before age 16 years, even after adjustment for age, background factors, previous psychiatric morbidity, and dieting behavior. The incidence is 2.5 times higher for 1 episode of abuse vs 4.9 times higher for 2 or more episodes of abuse vs no abuse.
• There is no clear association between childhood sexual abuse before age 16 years and subsequent symptoms of anorexia nervosa in girls.

CME Test