A Longitudinal Study of Severe and Enduring Eating Disorders
brief summary
The goal of this observational longitudinal study is to investigate characteristics and factors associated with the development of Severe and Enduring Eating Disorders (SEED). In this project, the researchers will follow two prospective cohorts of patients with eating disorders (ED), one adolescent (ages 14-17) and one adult (ages 18+), in terms of change in and impact of clinical, psychological, and biological risk factors. Data will be collected at baseline, after treatment, two years after baseline, and thereafter five, 10 and 20 years after baseline. Participants will be asked to undergo a physical examination, leave blood samples, be interviewed, and fill in questionnaires. If the participants are minors, their care takers will also fill in the questionnaires. The study aims to explore how clinical, psychological, and biological risk factors-including comorbidity, personality characteristics, difficulties with emotion regulation (ER), cognitive inflexibility, loneliness, severe ED symptoms, and inflammatory activation-contribute to a chronic course of the disorder.
detailed description
BACKGROUND, AIMS AND HYPOTHESES
Eating disorders (EDs) are psychiatric conditions characterized by a loss of control over food intake. The prevalence of anorexia nervosa (AN) is estimated at approximately 1-2%, while bulimia nervosa (BN) affects 2-3% of the population. EDs significantly impair functioning, have serious health consequences, and are associated with high mortality rates. Around 20% of patients with AN and 10% of those with BN develop a long-lasting illness, often referred to as Severe and Enduring Eating Disorders (SEED). While there is no scientific consensus on the definition of SEED, it is frequently defined as a duration of illness lasting seven years or more. Research suggests that factors maintaining EDs may differ from those that trigger them.
The underlying causes of EDs remain largely unknown, though their origins are considered multifactorial. Psychiatric comorbidities are highly prevalent in EDs, significantly influencing their course and outcomes. Personality disorders (PDs) are associated with poorer treatment outcomes for EDs, but longitudinal studies examining the trajectory of PDs in EDs are limited, and findings are inconsistent.
Dysfunctional emotion regulation (ER) has been identified as a transdiagnostic psychological risk factor for many psychiatric disorders, including EDs. ER difficulties can manifest as undercontrol, characterized by personality traits such as impulsivity and insufficient self-control, or overcontrol, characterized by emotional inhibition and excessive self-control och cognitive inflexibility. Some models propose that undercontrol is central to BN, while overcontrol are core features of AN. However, the course and stability of ER in EDs remain poorly understood due to a lack of longitudinal studies.
Another understudied factor in EDs is loneliness, encompassing perceived social isolation and a lack of connectedness. Loneliness has been linked to ER strategies, such as excessive self-control and emotional avoidance, which in youth can contribute to social isolation, reduced life satisfaction, and a higher risk of enduring mental health problems. The role of loneliness in SEED, however, is not well understood.
Further, research on EDs has proposed that biological factors, including dysregulation of the immune system, plays a role in the development and maintenance of the EDs. Studies indicate a pro-inflammatory state in AN, though it remains unclear whether this is a state or trait marker. The role of inflammation in BN is even less understood, and studies present mixed findings. Some evidence suggests an increased risk of BN in individuals with autoimmune or inflammatory diseases, highlighting the need for further investigation into inflammatory markers over the course of the illness.