Understanding suicidal ideation may help develop more effective suicide screening and intervention programs. The interpersonal and the cognitive-deficit theories seek to describe the factors leading to suicidal behavior. In the military setting it is common to find over- and under-reporting of suicidal ideation. This study sought to determine the relationship between these two models and determine to what degree their components can indirectly predict suicidal ideation.

Suicide attempters (n = 32) were compared with non-suicidal psychologically treated peers (n = 38) and controls (n = 33), matched for sex and age (mean 19.7 years). Pearson's analysis was used to quantify the relationship between the variables from the two models and hierarchal regression analysis was used to determine the explanation of suicidal ideation variance by these variables.

Suicide attempters have more difficulties in problem-solving, negative emotion regulation and burdensomeness compared with their peers (P < .001). These variables are all closely correlated with each other and to suicide ideation (r > ± 0.5; P < .001). Prior suicide attempt, loneliness and burdensomeness together explain 65% (P < .001) of the variance in suicidal ideation.

Suicidal ideation is strongly correlated with components of interpersonal and cognitive difficulties. In addition to assessing current suicidal ideation, clinicians should assess past suicide attempt, loneliness and burdensomeness.

Over half of individuals with eating disorders experience suicidal ideation at some point in their lives, yet few longitudinal studies have examined predictors of ideation in this at-risk group. Moreover, prospective research has focused on relatively distal or trait-level factors that are informative for distinguishing who is most at risk but not when. Little is known about more proximal or state-level risk factors that fluctuate within an individual, which is critical for determining when a person is most likely to engage in suicidal behaviors.

Women (N = 97) receiving treatment for their eating disorder completed questionnaires weekly to assess suicidal ideation and interpersonal constructs (i.e. perceived burdensomeness, thwarted belongingness) theorized to be proximal predictors of suicidal desire. Longitudinal multilevel models were conducted to examine both within- and between-person predictors of suicidal ideation across 12 weeks of treatment.

Statistically significant within-person effects for burdensomeness (β = 0.06; p < 0.001) indicate that when individuals have greater feelings of burdensomeness compared to their own average, they also experience higher suicidal ideation. We did not find any significant influence of thwarted belongingness or the interaction between burdensomeness and belongingness on suicidal ideation.

This study was the first to examine dynamic associations between interpersonal constructs and suicidal ideation in individuals with eating disorders. Results are only partially consistent with the Interpersonal Theory of Suicide and suggest that short-term changes in burdensomeness may impact suicidal behavior in individuals with eating disorders.