Eating disorders, especially Bulimia Nervosa (BN), are often mentioned as a possible impact of childhood sexual abuse. Indeed, there is a correlation: among women with BN, more have been sexually abused in their childhood. In a review of the research, Wonderlich et al. 1997 conclude that childhood sexual abuse "is a nonspecific risk factor for bulimia nervosa".
On the other hand, this risc is much lower than usually assumed. In some of the research, this correlation was not even significant (i.e. Pope & Hudson 1992, Pope et al. 1994, Kinzl et al. 1994 ). For a sample of 1099 women considered by Wonderlich et al. 1996, only between one sixth and one third of the cases of significant bulimic disturbance could be attributed to childhood sexual abuse.
Moreover, correlation does not mean causality.
First, there is a similar, may be even stronger, association between BN and other traumatic experiences like physical and psychological abuse, neglect, and adverse family background. This suggests that the common aspects of all these types of abuse should be suspected.
Second, there is some comorbidity with other negative impact. This suggests that there are common reasons for these different types of negative impact.
For causal explanation, there is a hypothesis (Waller) that self-criticism may be important. For this hypothesis there is already some empirical support. Tobin 1996 concludes: "self-criticism was the only primary coping strategy to differentiate abused from nonabused patients".
There is a lot of evidence for comorbidity with other psychiatric problems: The review of Wonderlich et al. 1997 indicates that childhood sexual abuse "is a nonspecific risk factor for bulimia nervosa, particularly when there is psychiatric comorbidity."
Miller et al. 1993 have found dissociative experiences more common in their bulimic group. Higher DES scores have been found also by Herzog et al. 1993.
Waller 1994 found "a secondary diagnosis of borderline personality disorder was associated with a reported history of sexual abuse" in 115 eating-disordered women.
This comorbidity seem high enough to suggest that they may give a causal explanation of the association between child abuse and BN: For example, Moyer et al. 1997 suggests that "psychological factors such as depression or weight satisfaction were more influential than is sexual abuse per se in the relationship between CSA and eating disorders". In the study of Casper 1997, "multiple regression analyses with family and individual psychopathology as independent variables in addition to sexual abuse showed only individual psychopathology to predict significantly abnormal eating behavior".
This suggests the following causal explanation: child abuse causes other psychopathology ( PTSD, depression) which are closely related with bulimic disorders.
Studies which consider also other negative influences show that a correlation with sexual abuse, if it has been found, is lower or comparable with the correlation of other negative childhood experiences like physical or psychological abuse (Rorty et al. 1994, Welch & Fairburn 1996). Rorty et al. 1995 reported significantly more physical punishment in a group of women with BN.
This association seems to be very strong. It may be even that the higher probability of sexual abuse if there are also other types of abuse and neglect is already sufficient to explain the observed correlation. Indeed, Rorty et al. 1994 have found that "Contrary to expectation, rates of sexual abuse did not distinguish the groups [of women with and without BN], except in combination with other forms of abuse.
A close association also exists for adverse family background (Kinzl et al. 1994, Kern & Hastings 1995, Hastings & Kern 1994 )
This relation may be used to explain some part of the association between CSA and eating disorders: Kern & Hastings 1995 have found that "one abnormality unique to bulimia was the family's heightened emphasis on achievement", and Miller et al. 1993 have found that "bulimic women had more negative and unusual mealtime experiences than nonbulimic women."
Only for repeated severe sexual abuse Welch & Fairburn 1996 have found a significant difference between cases of BN and controls with other psychiatric disorders. It was more common among cases of BN. See also Hastings & Kern 1994
There are no results about volitional relations.
Of course, in some studies the notion "sexual abuse" is used also for volitional sexual contacts. But the results of these studies cannot be used to prove some relation between volitional contacts and BN.
Many studies consider only unwanted sexual experiences as sexual abuse, and a widely distributed questionaire for sexual abuse - the Sexual Abuse Exposure Questionaire - too. Rorty marks this as a strenght that "mitigates against the problem encountered in some studies in which abuse is defined so liberally as to be almost meaningless".
Correlations have been found for women. I have not yet found any results about men except Neumark-Sztainer et al. 1996.