Microbiome of Depression & Treatment Response to Citalopram


About this study

The purpose of this study is to evaluate the feasibility of developing a microbiome probe of depression and to evaluate the microbiome change in a preliminary analysis of treatment response (n=20) vs. non response (n=20) to the antidepressant citalopram. This study is a 12 week open trial that will enroll approximately 80 participants (anticipated 40 study completers with paired biomarker data) with an episode of major depression, Bipolar I or Bipolar II and 40 age- and sex-matched healthy controls.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Outpatients or inpatients with nonpsychotic major depressive disorder (MDD) or Bipolar I or II Disorder.
  • A score of >16 on the QIDS
  • Outpatients or inpatients for whom antidepressant treatment is deemed appropriate by the treating clinician
  • Subjects who are between 18-65 years of age

Exclusion Criteria:

  • Contraindications to citalopram treatment
  • Axis I or II disorder other than depression that is the primary reason for seeking treatment intervention and/or psychiatric care
  • Subjects diagnosed with Borderline Personality Disorder (BPD) as their primary diagnosis.
  • For healthy controls, a first degree relative who has been diagnosed with an Axis I disorder
  • Patients with schizophrenia, schizoaffective disorder, or bipolar I disorder
  • Antidepressant treatment within 4 days of study (1 week if fluoxetine). Subjects currently on antidepressant medication with subtherapeutic results in terms of depression management after providing informed consent, will undergo a medication taper and discontinuation prior to initiation of citalopram treatment. The subject must be off of previous antidepressants for at least 4 days week prior to starting citalopram (1 week if fluoxetine). The subject will be closely monitored by the research study psychiatrist (with or without additional monitoring from primary clinical psychiatric providers). The medication taper is left up to the research study psychiatrist in consultation with patient's primary care or psychiatric provider. Study subjects who cannot be safely tapered from their medication or experience adverse effects during the taper will be excluded from the study
  • Study subjects using their antidepressant medication for management of nicotine dependence, chronic pain, migraine prophylaxis, or other diagnoses will not be eligible for the study unless they remain on a stable dose of the medication for the 12 weeks of the study.
  • Trazodone, melatonin, and diphenhydramine may be used as rescue medications for insomnia. Benzodiazepines may be used for treatment of anxiety, not to exceed 4 mg/24 hour of lorazepam
  • Subjects who are currently on an antibiotic or an antibiotic within 2 weeks. (Topical antibiotics are OK)
  • Daily use of aspirin, NSAID's or Warfarin (low dose of baby aspirin OK)
  • Subjects unable to give informed consent are excluded
  • Pregnant subjects will be excluded
  • Subjects who are currently breastfeeding and who plan to continue breastfeeding will be excluded
  • Postmenopausal women are not eligible for this study

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status

Rochester, Minn.

Mayo Clinic principal investigator

William Bobo, M.D., M.P.H.

Closed for enrollment

Jacksonville, Fla.

Mayo Clinic principal investigator

Teresa Rummans, M.D.

Closed for enrollment

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