Antidepressant Drug Use in Patients With T2D Lacks Research Antidepressant Drug Use in Patients With T2D Lacks Research

Researchers published the study covered in this summary on medRxiv.org as a preprint that has not yet been peer reviewed.

Key Takeaways

  • The authors of this systematic review attempted to assess and synthesize the long-term outcomes from observational studies of people with type 2 diabetes and comorbid depression who received treatment with prescribed antidepressants.

  • No studies were identified that matched the investigators’ prespecified inclusion criteria. The main reasons for exclusion were failure to meet the authors’ inclusion criteria for antidepressant treatment; unspecified case definitions for depression, type 2 diabetes, or both; short or unspecified duration of antidepressant treatment; and overly brief follow-up to assess outcomes.

Why This Matters

  • An estimated one quarter of people with type 2 diabetes have comorbid depression, and evidence shows an increased prevalence of depression in people with type 2 diabetes compared to those without. Depression is associated with poor glycemic control, development of diabetes-related complications, and decreased adherence to diabetes treatments. Successful treatment of depression in people with type 2 diabetes can potentially enhance both the physical and mental health of these patients.

  • Despite the potentially high number of people with type 2 diabetes and comorbid depression treated with antidepressants, the long-term impact of the treatment in this patient group is unknown.

  • The authors say this is the first systematic review that focuses on observational studies of the long-term outcomes of antidepressant treatment prescribed for the minimum recommended duration of at least 6 months in individuals with type 2 diabetes and comorbid depression. Previous reviews focused on results from randomized controlled trials, and the maximum follow-up of these trials was no more than 6 months.

Study Design

  • The investigators registered the design of their systematic review of observational studies prospectively on the PROSPERO website, run by the National Institute for Health and Care Research.  

  • The prespecified inclusion criteria encompassed observational studies of adults with both diagnosed depression and type 2 diabetes established with a record of a clinical diagnosis or patient self-report. In addition, patients had to have received antidepressant treatment for at least 6 months, and overall follow-up had to be for a minimum of 12 months. The researchers searched a variety of medical literature databases for relevant studies published through May 2021.

Key Results

  • The researchers screened 14,389 unique abstracts, a process that identified 63 full texts that qualified for a detailed review of their eligibility by the prespecified standards. No study that met all the inclusion criteria was identified during this process.

  • Shortcomings that led to exclusion of studies from the analysis (many studies had more than one excluding feature) included 49 did not meet the prespecified inclusion criteria for antidepressant use; 36 used an insufficient case definition for type 2 diabetes; 29 used an insufficient case definition for depression; 25 had insufficient follow-up; 14 had an incorrect study design; five did not use measurable outcomes; and three did not use a suitable comparator group.

  • The most common reason for exclusion, for 49 reports, was failure to meet the inclusion criteria for antidepressant treatment. This included 15 studies that didn’t identify a group of participants who were all known to have received antidepressant prescriptions through self-report, prescription records, or a clinician’s report. An additional 34 studies didn’t specify the duration of antidepressant treatment or didn’t meet the inclusion criteria of a minimum 6 months of treatment.

Limitations

  • The authors note that they applied strict inclusion and exclusion criteria for identifying patients with depression and type 2 diabetes, and that they also required a 6-month minimum duration of antidepressant treatment and follow-up. They said they applied these criteria to identify high quality and robust studies. They also rationalized the 6-month minimum follow-up criterion as reflecting treatment guidelines for use of antidepressant medications and to better represent long-term responses to treatment rather than initial responses. 

Disclosures

  • The study received no commercial funding.

  • Most of the authors had no commercial disclosures. One author, Ian C.K. Wong, reported being a board member for Jacobsen Medical and has received research grants from Amgen, Bayer, Bristol Myers Squibb, GlaxoSmithKline, Janssen, Medice, Novartis, and Pfizer.

This is a summary of a preprint research study, “A Systematic Review of Long-term Antidepressant Outcomes in Comorbid Depression and Type 2 Diabetes,” written by authors primarily based at University College London, UK, on medRxiv provided to you by Medscape. This study has not yet been peer reviewed. The full text of the study can be found on medRxiv.org.