Let’s define non-suicidal self-injury and disordered eating
Non-suicidal self-injury [or NSSI for short]: When talking about NSSI I refer to all those direct and deliberate behaviors aimed at damaging one’s own skin, and that do not have suicidal intents1, like for example, scratching until bleeding, cutting, hitting the head against the wall, etc… More detailed information about this can be found on the previous blog about Understanding Non-Suicidal Self Injury.
Disordered eating: When talking about disordered eating I refer to those behaviors that fall under the category of anorexia nervosa [clear underweight due to the restriction of food intake, together with a distorted body image and fear of gaining weight2], bulimia nervosa [body weight within the healthy range or elevated with episodes of binge eating, followed by behaviors aimed at avoiding weight gain, such as vomiting2], and binge-eating [elevated body weight, with recurrent episodes of binge eating but without behaviors aimed at avoiding weight gain3].
Now that these terms are clearer, I would like to go back to my original question and give you more information about the link between NSSI and disordered eating. In fact, almost 30 people out of 100 who are diagnosed with disordered eating also use some form of NSSI. This seems to be particularly true for those who suffer from bulimia4.
The association between NSSI and disordered eating has, from the very beginning of its discovery, interested researchers, who have tried to understand what comes first: NSSI (which leads to disordered eating) or disordered eating (which in turn leads to NSSI)?
Being able to answer this question would allow us to prevent the occurrence of both these behaviors. However, there is currently not much research that has been able to answer this question.
The reason is that to conduct such studies, researchers need to gather information from the same people over several years (you can imagine the cost and the effort to run such studies). The few scientific publications that exist at the moment seem to show that these two behaviors influence each other overtime.
For example, adolescents who engage in NSSI repetitively at age 14 seem to be more likely to develop an eating disorder by age 175. At the same time, people who show symptoms of eating disorders are more likely to engage in NSSI later on in their life6.
So, according to the current research, it seems like disordered eating and NSSI go in a vicious cycle, influencing each other.