Doctoral defence: Kärol Soidla “Latent profiles and developmental trajectories of eating disorder symptoms”

On December 15 at 14:15 Kärol Soidla will defend her doctoral thesis “Latent profiles and developmental trajectories of eating disorder symptoms” for obtaining the degree of Doctor of Philosophy (in Psychology).

Supervisor:
Professor Kirsti Akkermann

Opponent:
Professor Glenn Waller, Sheffieldi Ülikool (UK)

Summary
Eating disorders are serious psychiatric conditions associated with significant psychological, physical, and social consequences. Disordered eating is also frequently observed in the general population, for example in the form of strict dieting or occasional binge eating episodes. The aim of this doctoral dissertation was to examine how different facets of perfectionism and impulsivity are related to disordered eating and eating disorders, and how disordered eating develops during adolescence. The study applied methods aimed at identifying patterns of personality and behaviour, allowing the distinction and analysis of similar subgroups within heterogeneous samples.

Depending on the study, the samples included either individuals diagnosed with an eating disorder or adolescents from the general population. The identified profiles differed in their levels of perfectionism, impulsivity, and disordered eating patterns, as well as in the intensity of these characteristics. Among individuals with eating disorders, the co-occurrence of high negative perfectionism and dysfunctional impulsivity was more strongly associated with pronounced eating disorder symptoms. In contrast, among adolescents from the general population, disordered eating was most evident in the group characterized by high negative perfectionism without marked impulsivity. The differentiation between profiles proved to be more informative and stable when eating disorder symptoms were included alongside personality traits.

The development of disordered eating in adolescence (ages 11–16) appeared multifaceted, following several developmental pathways. Body dissatisfaction remained stable from ages 11–12, whereas behavioural manifestations became more distinct around ages 13–14. Membership in higher-risk trajectories was predicted by higher body mass index, perceived social pressure regarding appearance, and perfectionism.

Personality-based assessment may help identify more vulnerable individuals early and guide the personalization of interventions. The findings also suggest that preventive efforts should begin before early adolescence, focusing on reducing perfectionism and body image–related concerns.