An observational study in Depression, Psychiatric Diagnosis and Personality Disorders, sponsored by Region Skane. Recruiting at 2 sites in Sweden. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-30.
Sponsored by Region Skane · Observational
The project investigates long-term prognosis and predictors of treatment outcomes for difficult-to-treat depression in patients in secondary psychiatric care. The current patient cohort was collected in 2012-2021 in the study "Pharmacogenetics in patients with depression with specific focus on difficult-to-treat depression, suicide attempt and CYP2D6". The cohort consists of 415 patients, examined carefully regarding diagnostic assessment and earlier treatment. All participants were also genotyped for the drug metabolizing enzymes CYP2D6 and CYP2C19. Blood samples were stored in biobank for other analyses linked to prognostic markers.
The patient cohort will now be followed up with a review of medical records and extraction of register data for a period of 5 years after their participation in the original study. The purpose of the study is to improve treatment and increase knowledge about long-term prognosis in difficult-to-treat depression. This is done by examining symptom profiles, monitoring clinical course and suicidality, and examining prognostic markers.
BACKGROUND
It is very important to understand the course of depressive disorders over time in long time follow-up studies. A cross-sectional observational study "Pharmacogenetics in depressed patients with a special focus on difficult-to-treat depression, suicide attempts and CYP2D6" (n=415) was performed in Sweden 2012-2021. Participants were genotyped for enzymes within the Cytochrome P450 system - CYP2D6 and CYP2C19. Participants were also examined very carefully with regard to diagnostic assessment with structured and semi-structured diagnostic instruments: MINI neuropsychiatric interview (MINI) and structured clinical interview for DSM-IV-TR axis II (SCID-II). Comprehensive psychipatological rating scale (CPRS) was used as well as Montgomery Asberg depression rating scale (MADRS), the UKU side effect rating scale (UKU-SERS) , Suicidal assessment scale (SUAS) and Alcohol Use Disorder Identification Test (AUDIT) and Drug Use Disorder Identification Test (DUDIT) as well as thorough survey of the clinical course of psychiatric symptoms. Blood samples were collected and stored in biobank. The participants with CYP2D6UM and CYP2D6PM were offered pharmacological counseling to optimize treatment during 8 weeks.
The same patients will now be followed over a five-year period after participation in the original study, in order to better understand the long-term prognosis of depression and the factors that can predict the course of the disorder over time.
OBJECTIVE
The overall goal is to improve treatment and increase knowledge about difficult-to-treat depression, as well as to investigate how biological and clinical variables can predict treatment outcomes and long-term outcomes.
PURPOSE
To investigate diagnoses and diagnostic assessment, long-term prognosis, symptom profiles and prognostic markers as well as suicidality and effect of pharmacologic counseling in depression. The cohort contains patients with both unipolar and bipolar depression.
METHOD
Research subjects who have participated in the original study during the period 2012-2021 (n=415) will participate in the follow up study unless they oppose to do so. The original study has already been presented in earlier publications with regard to diagnostics treatment linked to clinical parameters and suicide attempts, inflammation, vitamin D, mitochondrial DNA, CYP2D6, and coping.
Data collection for this follow-up study is based on an approved opt-out procedure from the Swedish Ethical Review Authority (dnr: 2024-04820-02 and 2025-03351-02)). Participants are given the opportunity to decline participation in the study by responding via letter or questionnaire responses digitally. If participants do not respond within 4 weeks, they are automatically included in the study.
Data will be collected through medical records review and extraction of register data. The data collection will be for a period of 5 years from participation in the original study.
The following information is collected from medical records: Information on suicide attempts, inpatient treatment, emergency room visits, outpatient visits, treatment received, ICD diagnoses, descriptions of personality functioning, markers for clinical improvement, if CYP2D6UM and CYP2D6PM have been subject to specific considerations in choice of drug treatment.
Registers will be used when needed for data collection, from the Longitudinal Integration Database for Health Insurance and Labour Market Studies, the Pharmaceutical Register, the Patient Register, the Cause of Death Register.
8,577 studies on the registry are indexed under Depression; 1,720 are open to participants now.
This study's planned enrollment of 415 is above the median of 175 across 1,257 observational studies indexed under Depression.
Browse Depression studies →Region Skane is the lead sponsor of 386 studies on the registry; 122 are open to participants now.
Counted across the registry records on this site, refreshed daily.
415 patients from the study "Pharmacogenetics in depressive patients with specific focus on difficult-to-treat depression, suicide attempt and CYP2D6". The study population has been well described in earlier publications.
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Participation in the study "Pharmacogenetics in depressive patients with specific focus on difficult-to-treat depression, suicide attempt and CYP2D6"
Exclusion Criteria:
Not wanting to participate in the follow-up study
No intervention is used.
Suicide attempt and suicide
The frequency of suicide attempts and completed suicides in the patient sample over the follow-up period of 5 years
Time frame: 5 years follow-up after baseline visit.
Clinical course of depression
Course of depressive disorder during the follow-up period measured by information from medical records, where the reserach psychiatrist makes an assessment dichotomized as improved or not improved based on the available information.
Time frame: 5 years follow-up after baseline visit
Comparison of diagnostic assessment for personality disorders
Comparison of frequency of DSM-IV-TR personality disorders and ICD-11 personality disorders in the sample. ICD-11 personality disorders will also be divided into degree of difficulty as well as which specifiers of prominent traits are present in the population of difficult-to-treat depression
Time frame: Baseline data and 5 years follow-up from inclusion.
Course and diagnostic characteristics of bipolar disorder
Historical order of diagnoses before bipolar diagnosis and the development of diagnostic assessment during follow-up as well as personality assessment according to DSM-IV and ICD-11.
Time frame: Baseline data and 5 years follow-up after inclusion.
Results from pharmacological counseling for CYP2D6UM och CYP2D6PM
Change in score for Montgomery Åsberg Depression Rating Scale from week 0 to 8 (total of 9 weeks) during pharmacological counseling. Data from medical records for 5 years follow-up will be used to investigate adherence to recommendations during pharmacologic counseling and in a long term perspective.
Time frame: Nine weeks of pharmacological counseling after baseline and 5 years follow-up from baseline visit
Prediction of long-term prognosis of depressive symptom profiles
Data on clinical outcome over 5 years follow-up for depressive symptom profiles with specific focus on anhedonic symtom profile derived from the Comprehensive Psychopatholocial Rating Scale (CPRS) and depression characteristics.
Time frame: 5 years follow-up from baseline visit
Course of disease related to dopamine D3 receptor and other biomarkers
The relationship between the course of depressive disorder and biomarkers including dopamine D3 receptor, other biomarkers of dopaminergic function, inflammation and other types of biomarkers
Time frame: 5 years follow-up from baseline visit
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