Evaluation of a Diabetes-specific Cognitive Behavioural Treatment for Subthreshold Depression

Study Overview
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Brief Summary
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This work is supported by the Kompetenznetz Diabetes mellitus (Competence Network for Diabetes mellitus) funded by the Federal Ministry of Education and Research (FKZ 01GI0809). Approximately one third of diabetic patients has elevated depressive symptoms. The majority of these patients are suffering from a subthreshold depression. In spite of the fact that subthreshold depression has an equivalent negative impact on the prognosis of diabetes as clinical depression, there is no specific intervention tool. The main objective of this project is to develop a diabetes specific cognitive behavioural treatment (DS-CBT) for diabetic patients with subthreshold depression. In a randomized trail DS-CBT is compared to standard diabetes education. A total of 188 diabetic patients will be recruited and randomly assigned to the two treatment conditions. The expected main outcome is the reduction of subthreshold depression under DS-CBT in a 12 month follow up. Secondary variables are improvement of glycaemic control, quality of life, diabetes self-management as well as reduction of health care costs and modification of inflammatory parameters.

Detailed Description
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Elevated rates for depression in diabetic patients are of clinical significance for diabetology. Depressive disorders are doubled compared to patients without diabetes. A meta-analysis showed that a proportion of 20% of diabetic patients showed subthreshold depression, defined as elevated depressive symptoms without meeting criteria for clinical depression. Depression in diabetes is associated with a reduced quality of life, more diabetes related distress, and higher health related costs. But besides this, depression in diabetes seems to be an independent negative prognostic factor for morbidity and mortality. Furthermore subthreshold depression is a major barrier of an effective self-management of the disease. Until now antidepressive therapies are only evaluated in clinically depressed diabetic patients. For the majority of depressed diabetic patients suffering from subthreshold depression no evaluated specific intervention concept exists. Since subthreshold depression often is associated with diabetes related distress a diabetes specific intervention was developed to support patients to increase their problem solving skills, modify their depressive cognitions and improve their coping with diabetes related distress. It consists of five sessions and is delivered as a group intervention. This study is an efficacy trial. In this randomized trial the efficacy of this newly developed intervention is compared to a control condition consisting of five standard diabetes education lessons. The primary outcome variable is the reduction of depressive symptoms twelve months after the intervention. Secondary outcome variables are the quality of life, metabolic parameters, self-care behavior and other psychosocial aspects. Furthermore the possible covariation between change of depressive symptoms and inflammatory and immune markers will be analyzed.

Official Title
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Development and Evaluation of a Diabetes-specific Cognitive Behavioural Treatment (DS-CBT) for Diabetic Patients With Subthreshold Depression

Conditions
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Depressive Symptoms, Diabetes Mellitus

Intervention / Treatment
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* Behavioral: Diabetes-Specific CBT (DS-CBT)
* Behavioral: Standard Diabetes Education


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diabetes mellitus Elevated depressive symptoms (regarding to CES-D) Age >= 18 and <=70 Sufficient German language skills Informed consent Exclusion Criteria: Current MDD Current schizophrenia/ psychotic disorder, eating disorder, bipolar disorder, addictive disorder, personality disorder Current antidepressive medication Current psychotherapy Severe physical illness (i.e. cancer) Being bedridden Guardianship

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Diabetes-Specific CBT (DS-CBT)<br>Cognitive Behavioral Intervention (Group) focusing on Diabetes-Specific Problems | Behavioral: Diabetes-Specific CBT (DS-CBT)<br>* 5 Group Sessions with a duration of 90 Minutes each, including the following cognitive-behavioral Intervention Methods focusing on Diabetes Distress and Hassles: Problem Analysis and Definition Problem Solving Intervention Cognitive Restructuring Activation of personal and social Resources Goal Definition and Agreement<br>* Other names: Diabetes-Specific Cognitive-Behavioral Group Sessions;|
| Active Comparator: Standard Diabetes Education<br>Standard Diabetes Education Lessons will be given to quantify the unspecific antidepressive Effects of Participation in Group Sessions with social Contact and Acquisition of Knowledge. | Behavioral: Standard Diabetes Education<br>* Standard Diabetes Education Lesson including Health Care and specific Topics (e. g. Blood Pressure) Social Aspects of Living with Diabetes Diabetes Complications Sports, Activities and Exercise Healthy and unhealthy Food, Vitamins, Cooking Recommendations and Recipes Foot Care: Exercises, Care and Control, Sensibility, Injuries, diabetic Neuropathy<br>* Other names: Educative Group Lesson and Discussion;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Depressive Symptoms (CES-D Score) | The Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depressive symptoms. The CES-D assesses the frequency of 20 typical symptoms of depression during the previous week on a 4-point Likert scale. Summing of the item scores estimates the total score with a range between 0 and 60 and higher scores indicating more severe depressive mood. Based on the measurement of depressive symptoms at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated. | Baseline, 12 month FU | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quality of Life (EQ-5D TTO Score) | The EuroQol Five Dimension Questionnaire (EQ-5D) was used to assess health-related quality of life (HRQOL). The EQ-5D assesses five dimensions of HRQOL using a 3-point scale. The item scores are weighted based on population data and used to calculate a standardised total score from 0 to 1 with higher scores indicating better HRQOL. Based on the measurement of HRQOL at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated. | Baseline,12 month FU | 
| Diabetes-specific Distress (PAID Score) | The Problem areas in Diabetes Scale (PAID) was used to assess diabetes-specific distress. The PAID assesses diabetes-specific distress using 20 items and a five-point Likert scale (0 - 4). Item scores are summed and transformed to a range from 0 - 100 with higher scores indicating higher distress. Based on the measurement of diabetes-specific distress at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated. | Baseline, 12 month FU | 
| Diabetes Self-Care (SDSCA Score) | The Summary of Diabetes Self-Care Activities Measure (SDSCA) was used to assess diabetes self-care. The SDSCA assesses the number of days of the previous week (0 - 7) on which several specific self-care activities (appropriate diet, physical activity, self-monitoring of blood glucose, foot care) were performed. The item scores are summed and averaged to a total score from 0 to 7 with higher scores indicating better overall self-care. Based on the measurement of diabetes self-care at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated. | Baseline, 12 month FU | 
| Diabetes Acceptance (AADQ Score) | The Acceptance and Action Diabetes Questionnaire (AADQ) was used to assessment of diabetes acceptance. Using 11 items on diabetes-related experiential avoidance behaviours and a 5-point Likert response scale (1 - 5), the AADQ estimates the overall level of diabetes acceptance. Item scores are summed to a total score between 11 and 55 with higehr scores indicating better acceptance. Based on the measurement of diabetes acceptance at baseline and 12-month follow up, the difference of the test scores between baseline and 12 month follow up was calculated. | Baseline, 12 month FU | 
| Glycemic Control (HbA1c) | The HbA1c was used as measure of glycemic control. All blood samples were analysed in a central laboratory using the Bio-Rad II Turbo analyser; the measurement units were %-points. Based on the measurement at baseline and 12-month follow up, the difference of the HbA1c values between baseline and 12 month follow up was calculated. | Baseline, 12 month FU | 
| Inflammatory Marker IL-6 | The inflammatory marker Interleukin 6 (IL-6) was assessed as measure of distress-related immune activity. The differences of the serum-concentrations between baseline and 12 month follow up were calculated. | Baseline, 12 month FU | 
| Inflammatory Marker IL-1Ra | The inflammatory marker Interleukin 1 receptor antagonist (IL-1Ra) was assessed as measure of distress-related immune activity. The differences of the serum-concentrations between baseline and 12 month follow up were calculated. | Baseline, 12 month FU | 
| Inflammatory Marker Hs-CRP | The inflammatory marker high sensitivity C-reactive protein (hs-CRP) was assessed as measure of distress-related immune activity. The differences of the serum-concentrations between baseline and 12 month follow up were calculated. | Baseline, 12 month FU | 
| Health-care Costs: Health-care Utilisation | Several aspects of interest regarding diabetes-related health-care costs were assessed in order to evaluate potential reductions of health-care costs following the treatment. Measurement was performed using retrospective interview refering to the previous 6 months: The assessed aspects were 1.) the number of out-patient medical appointments as a measure of costs related to health-care utilisation, 2.) the number of days on sick leave as a measure of costs related to non-productive time and 3.) the number of daily taken prescription medications as a measure of costs related to medication intake. For each aspect, the difference of the numbers between baseline and 12 month follow up was calculated. | Baseline, 12 months-FU | 
| Health-care Costs: Non-productive Time | Several aspects of interest regarding diabetes-related health-care costs were assessed in order to evaluate potential reductions of health-care costs following the treatment. Measurement was performed using retrospective interview refering to the previous 6 months: The assessed aspects were 1.) the number of out-patient medical appointments as a measure of costs related to health-care utilisation, 2.) the number of days on sick leave as a measure of costs related to non-productive time and 3.) the number of daily taken prescription medications as a measure of costs related to medication intake. For each aspect, the difference of the numbers between baseline and 12 month follow up was calculated. | Baseline, 12 months-FU | 
| Health-care Costs: Medication Intake | Several aspects of interest regarding diabetes-related health-care costs were assessed in order to evaluate potential reductions of health-care costs following the treatment. Measurement was performed using retrospective interview refering to the previous 6 months: The assessed aspects were 1.) the number of out-patient medical appointments as a measure of costs related to health-care utilisation, 2.) the number of days on sick leave as a measure of costs related to non-productive time and 3.) the number of daily taken prescription medications as a measure of costs related to medication intake. For each aspect, the difference of the numbers between baseline and 12 month follow up was calculated. | Baseline, 12 months-FU | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Light affective Disorder, Subclinical depressive Symptoms, Diabetes mellitus, Late Complications, Markers of Inflammation, Subthreshold Depression, Diabetes-related Distress, Minor Depression