Eating disorders and personality

Abstract

Eating disorders are serious psychiatric conditions often demanding specialized psychiatric care. Several effective treatments have been developed and disseminated, but more needs to be done, as not all patients respond well to intervention, let alone achieve recovery. Obvious candidates such as eating disorder diagnosis, symptoms and psychiatric comorbidity have generally failed to explain variability in prognosis and outcome, warranting investigation of a wider range of relevant factors. Accumulating evidence suggests personality as an avenue to better understand psychopathology. This dissertation investigated how personality could increase the understanding of eating disorders and their treatment.

The first aim was to investigate how patients with eating disorder differed from normal controls (Study I) on the five-factor model of personality. The second aim was to investigate if and how personality could explain variance in eating disorder symptoms and other psychopathology (Study I). The third aim was to test if personality could predict outcome from two different interventions: day-patient treatment (Study II) and internet-based treatment (Study III). Since personality is also susceptible to change, the final aim was to investigate personality change over time in patients and how change patterns related to treatment and course of the eating disorder (Study IV).

Longitudinal data from a clinical sample of adult female patients with eating disorders was collected, including psychiatric diagnoses, symptoms, personality, and treatment. In Study I, patients were cross-sectionally compared to age-matched controls on personality. Study II examined if personality at admission could predict outcome from group-based psychodynamic day-patient treatment (DAY). Study III examined if personality could predict outcome from internet-based cognitive behavioral therapy (iCBT). In Study IV, personality was assessed at three time points, before treatment, at termination and at six-month follow-up.

Patients differed significantly from controls on the majority of personality traits. Personality could further explain variance in both general and eating disorder specific psychopathology. Extraversion and Assertiveness predicted both eating disorder improvement and remission after DAY whereas both Openness to Experience and Conscientiousness predicted a better outcome from iCBT. Over time, patients decreased in Neuroticism and increased in Extraversion, Openness to Experience and Conscientiousness. There was considerable individual variability in personality change and more than a quarter of patients reliably changed per trait. Patients remitting after treatment showed similar change of increased Assertiveness, Competence, Self-discipline, Openness to Actions, and Positive Emotions. Patients’ personality differed significantly from controls and was associated with both psychopathology and treatment outcome. Personality changed significantly towards normalization, particularly in remitted patients. This project concludes that personality is meaningfully linked to eating disorders and is a malleable aspect of the patient. Greater consideration of personality may help improve treatment.