The main aim of this study is to identify biological and psychological characteristics as risk factors in individuals with severe and enduring eating disorders (SEED).

Specifically, the investigators aim to:

1. in a cohort of well-diagnosed eating disorder patients from 2005 followed up in National health registers, explore risk factors at baseline (recorded 2005-2007) for development of later SEED (the registry based cohort).
2. replicate the findings in a new sample of 50 adults with ongoing SEED. Participants will be assessed diagnostically and physically, and asked to fill out questionnaires and leave blood samples (the ongoing SEED sample compared with the register based cohort).
3. in a sample of 50 adults with SEED, explore demographic, biological, clinical, and psychological factors and examine the relation between these factors and symptom severity and functional impairment (the ongoing SEED sample).
4. explore participants perspectives on their symptoms and received care (the ongoing SEED sample).

BACKGROUND, AIMS AND HYPOTHESES

Clinical factors such as psychiatric comorbidity and personality disorders, psychological and personality characteristics related to dysfunctional emotion regulation and loneliness, and biological factors such as dysregulation of the immune system, may all play a role in the developement, maintenance, and relapse of eating disorders. However, research in this field is scarce.

This projects aims is to increase our knowledge about risk factors for a severe course in eating disorders.

Hypotheses are:

• Personality disorders, comorbid psychiatric disorders and a high symptom load (generally and specifically for eating disorder symptoms) will be related to the development of SEED in the register based cohort

• The relation between SEED and personality disorders, comorbid psychiatric disorders and a high symptom load in the register based cohort will be replicated in the ongoing SEED sample

• In the ongoing SEED sample, symptom severity and functional impairment will be related to

  • Personality traits
  • Emotion dysregulation, maladaptive overcontrol and maladaptive undercontrol
  • Increased inflammation
  • More pronounced loneliness
  • Cognitive inflexibility

Primary outcomes are

• for aim 1: SEED at follow-up.
• for aim 2: factors identified from the register based study (aim 1). Thus, primary outcomes for aim 2 will be added to the protocol after analyses for aim 1 has been conducted.
• for aim 3: symptom severity and functional impairment
• for aim 4: patient perspectives of their symptoms and received care

Secondary outcomes are

• for aim 1: functional impairment, psychiatric and somatic comorbidity
• for aim 3: personality traits, emotion dysregulation, maladaptive overcontrol and maladaptive undercontrol, increased inflammation, more pronounced loneliness, cognitive inflexibility

PROCEDURE

The register based cohort: This adult cohort was consecutively recruited at the Eating Disorder Unit at the Uppsala Department of Psychiatry between 2005 and 2007. Of all 297 patients who came to the unit 218 (73%) participated. They were diagnosed according to gold standard including PD diagnoses, and thoroughly characterized in respect to clinical characteristics. They will be followed in national registries held by Statistics Sweden and the National Board of Health and Welfare, and these registers include the Swedish National Inpatient Register (IPR), the Longitudinal integrated database for health insurance and labour market studies (LISA) and the Registry of household statistics and the Swedish Medical Birth Register. By using registers both medical and social outcome can be examined. Factors from baseline can be related to outcome.

Tho ongoing SEED sample: Adult participants with SE-ED will be recruited through the ordinary staff that sees the participants at the Eating Disorder Unit at the Uppsala Department of Psychiatry combined with flyers and posters at the ED unit, through patient organizations, through the Uppsala University homepage, and through media. Those who themselves identify as having at least seven years duration of their ED and shown no or little response to treatment (SE-ED) who are interested in the study, will be guided to a web link were screening questions are provided. Inclusion criteria are having more than seven years of ED duration, having at least one evidence-based treatment without remission or resulting in relapse. Those completing the screening will be contacted, informed verbally in writing about the study and those fulfilling inclusion criteria will be invited to participate and sign an informed consent form. The investigators plan to include 50 participants. All participants will be invited to undergo a systematic diagnostic evaluation. The systematic evaluation consists of a clinical anamnestic history and three structured diagnostic interviews; either the MINI for DSM 5 or the Structured Clinical Interview for DSM-5 Axis I Disorders- Clinical Version (SCID-I CV) and Structured Clinical Interview for DSM-5 Personality Disorders (SCID-5-PD) assessing personality disorders. Participants also undergo the Eating Disorder Examination interview (EDE). Participants are also weighed and measured. All diagnostic assessments are conducted by psychologists physicians or trained students, who have received training in the procedure and who are co-rated. Participants will also be asked about collection of biomarkers through Uppsala psychiatric patient samples (UPP), which is an infrastructure for the collection of biological materials at the Department of psychiatry at Uppsala University Hospital. All participants will be invited to take blood samples and inflammatory markers will be analyzed in accordance with the informed consent for UPP. After the structured evaluation, they will be interviewed about their perspectives on their symptoms and received care using a semi-structured interview guide. All interviews will be audio taped and transcribed verbatim.

DATA ANALYSES

For aim 1: Stratified Cox regression models will be estimated with year 2005 as entry time. Hazard ratios (HR) and corresponding 95% confidence intervals (CIs) will be calculated. Cumulative indices will be calculated and illustrated with Kaplan-Meier curves.

For aim 2: Descriptive statistics and generalized linear models will be performed comparing three groups: non-SEED and SEED from the register based cohort and SEED from the ongoing sample according to psychiatric symptoms, severity, comorbidity, personality disorders.

For aim 3: For the primary outcomes, generalized linear models will be used to analyze if more pronounced symptom severity and lower level of functioning will be explained by personality traits, emotion dysregulation, maladaptive overcontrol and maladaptive undercontrol, increased inflammation, more pronounced loneliness, cognitive inflexibility. Participants will be asked about collection of biomarkers through Uppsala Psychiatric Patient samples (UPP) (ethics approval Dnr 2012/081), which is an infrastructure for the collection of biological materials at the Department of Psychiatry at Uppsala University Hospital. All participants will be invited to participate in UPP and inflammatory markers will be analyzed in accordance with the informed consent for UPP. Inflammatory markers will be analyzed using an electrochemilumine scence sandwich immunoassay, Meso Scale Discovery (K15049D and K15198D, Rockville, MD, USA) a multiplex platform. For protein hormones, such as plasma adiponectin and leptin, a solid phase sandwich enzyme linked immunosorbent assay (ELISA) (Mercodia AB, Uppsala, Sweden) will be used. For the secondary outcomes, descriptive statistics will be presented.

For aim 4: Participant perspectives will be analysed qualitatively with thematic analyses

For aim 1 (register based cohort):

Incl. criteria:

Attended care for eating disorders at Uppsala University Hospital between 2005 and 2007 and accepted to be included in a local quality register.

Excl. criteria: None

For aim 2 (ongoing SEED sample and register based cohort)

Incl. criteria:

• For ongoing SEED sample: Minimum age of 18, impairing eating disorder symptoms for at least seven years, and having at least one evidence-based treatment without remission or resulting in relapse.
• For register based cohort, see above.

Excl. criteria:

• For ongoing SEED sample: Eating disorders symptoms in need of emergency care, high risk for suicide, and an inability to respond to the questionnaires due to lack of knowledge in Swedish.

For aim 3 and 4 (the ongoing SEED sample). See above.

The register based cohort:

This adult cohort was consecutively recruited at the Eating Disorder Unit at the Uppsala Department of Psychiatry between 2005 and 2007. Of all 297 patients who came to the unit 218 (73%) participated in the study. They were diagnosed according to gold standard including PD diagnoses, and thoroughly characterized in respect to clinical characteristics.

The ongoing SEED sample:

Study population are individuals that themselves experience that their eating disorder have affected them in a significant way during at least the last seven years, who report having gone through at least one evidence-based treatment attempt, and that are willing to participate in the study. This adult sample will be recruited from the Eating Disorder Unit at the Uppsala Department of Psychiatry, via advertisement, through patient organizations, and through media. We plan to include 50 patients.

Data will not be made publicly available due to confidentiality but can be provided upon reasonable request.