Working… Menu

The Effect of Acute Minocycline Administration on Emotional Processing and Cognition in Healthy Volunteers

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03768557
Recruitment Status : Completed
First Posted : December 7, 2018
Last Update Posted : April 18, 2019
Information provided by (Responsible Party):
University of Oxford

Brief Summary:
There is growing interest in the possibility of producing more effective antidepressant treatments that target a wider range of pathways involved in depression, including anti-inflammatory and anti-glutamatergic systems. Minocycline is a novel pharmacological agent; in addition to its antibiotic and anti-inflammatory properties, it also acts in the brain as an anti-glutamatergic and anti-oxidant agent. Since both excessive glutamate and oxidative stress are implicated in major depression, and appear to be connected to pro-inflammatory activity, this drug offers a unique tool with which the investigators can measure the effects of targeting these pathways on emotional processing. Participants will receive a single dose of either the drug (200 mg minocycline) or placebo, and will then undergo a well-validated computerised battery of emotional processing tasks that have previously been shown to be sensitive to standard antidepressant drugs. Tasks include presentation of positive and negative emotional words or pictures, to which participants' responses are measured. These tasks have been widely used previously without any adverse effects.

Condition or disease Intervention/treatment Phase
Mood Cognitive Change Drug: Minocycline Other: placebo Not Applicable

Detailed Description:

Current antidepressant treatments, which largely target monoamine pathways, are efficacious in treating many aspects of major depression, however it is estimated that more than 30% of depressed patients fail to respond to standard antidepressant medications. Thus, there is a strong clinical need to identify and investigate novel treatment strategies that target different pathways involved in the pathophysiology of mood disorders. Mounting evidence indicates a potentially important role of inflammation in major depression; both clinical and animal studies have shown that pro-inflammatory cytokines can induce a behavioural repertoire of symptoms collectively referred to as 'sickness behaviours,' which include cognitive and mood symptoms, such as depression, anxiety, memory impairment, fatigue and anhedonia. Furthermore, elevated levels of peripheral pro-inflammatory cytokines, such as tumour necrosis factor (TNF)-α and interleukin (IL)-6, have been consistently reported in clinical mood disorders, including major depression. Evidence also points to the ability of pro-inflammatory cytokines to cause excitotoxicity (due to increased release of glutamate) and oxidative stress that are strongly implicated in the pathophysiology of major depression. Such evidence has therefore led to growing interest in testing effects of anti-inflammatory treatments on mood and emotional function to investigate whether the inflammatory-mood pathway could represent a novel drug target for new antidepressant therapies.

Minocycline has been selected for use in the present study as it is a pharmacologically interesting agent with an unusual combination of anti-inflammatory activity, in addition to anti-glutamatergic, anti-oxidant and neuro-protective actions. Thus, owing to its central action on systems that are thought to be involved in major depression, minocycline provides an interesting tool to investigate effects on cognition and emotional processing, particularly negative affective biases.

Negative affective biases in emotional processing are highly relevant to clinical mood disorders and they are well-recognised in the aetiology and maintenance of depression, such that depressed individuals are more likely to interpret, focus on and remember negative compared to positive emotional cues in self-relevant neuropsychological tasks. Antidepressant treatments have been shown to cause early, subconscious positive changes in emotional processing biases, which are evident in computerised tasks after one single dose of antidepressant. Recent theory suggests that over time this positive change in emotional bias contributes to improved mood.

Since elevated inflammatory markers appear to negatively affect mood and neuropsychological function, the investigators believe there is a need to expand our understanding of the psychological effects of reducing inflammatory markers. To do so, subjects will be administered either a single dose of 200 mg minocycline or placebo, after which they will complete a well-validated computerized battery of psychological tasks, which includes paradigms such as facial expression recognition, emotional categorization and emotional memory tasks that have previously been shown to be sensitive to conventional antidepressant treatments in healthy volunteers.

The results of this study will be compared to effects of common antidepressant treatments found using this same model within the investigators' lab and others. If effects are found to be comparable, this could not only provide further support for the emotional processing theory of antidepressant action, but it could also help to identify novel therapeutic targets for new treatments that could benefit depressed patients who do not respond successfully to current antidepressants.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 40 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: The Effect of Acute Minocycline Administration on Emotional Processing and Cognition in Healthy Volunteers
Actual Study Start Date : April 26, 2017
Actual Primary Completion Date : October 25, 2018
Actual Study Completion Date : October 25, 2018

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Minocycline
single dose of minocycline (200mg)
Drug: Minocycline
Minocycline (200mg)

Placebo Comparator: Placebo
lactose pills (400mg)
Other: placebo
Lactose (400mg)

Primary Outcome Measures :
  1. Facial Expression Recognition Task [ Time Frame: 2 hours ]
  2. Emotional Categorization Task [ Time Frame: 2 hours ]
  3. Emotional Recall Task [ Time Frame: 2 hours ]
  4. Emotional Recognition Memory Task [ Time Frame: 2 hours ]
  5. Attentional Dot-Probe [ Time Frame: 2 hours ]

Secondary Outcome Measures :
  1. N-back Task [ Time Frame: 2 hours ]
  2. Contextual Cueing Task [ Time Frame: 2 hours ]
  3. Priming Task [ Time Frame: 2 hours ]

Other Outcome Measures:
  1. Concentration of the inflammatory marker TNF-alpha in serum Serum inflammatory cytokines and metabolites [ Time Frame: 0 and 4 hours ]
  2. Concentration of the inflammatory marker IL-6 in serum [ Time Frame: 0 and 4 hours ]
  3. Concentration of the inflammatory marker C-reactive protein in serum [ Time Frame: 0 and 4 hours ]
  4. Concentration of the stress hormone cortisol in serum [ Time Frame: 0 and 4hours ]
  5. Concentration of metabolites (amino acids and lipids) in serum [ Time Frame: 0 and 4 hours ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Participants are willing and able to give informed consent for participation in the study
  • Male or female, aged between 18 and 55
  • Body mass index (BMI) within the range of 19 - 30 kg/m2
  • Sufficiently fluent in English to understand the tasks and instructions
  • Female subjects must be outside of their pre-menstrual week on the testing day

Exclusion Criteria:

  • Current or past history of any psychiatric disorder (e.g. depression, anxiety)
  • Any medical contra-indication (for example hepatic impairment)
  • Current use of any medication which, in the opinion of the study physician, will interfere with minocycline or cause any contraindications
  • Known hypersensitivity to tetracyclines or to any of the excipients in minocycline capsules
  • Steroidal or non-steroidal anti-inflammatory medication within preceding 2 weeks, including aspirin and ibuprofen
  • Congenital or acquired immune deficiency (including participants receiving immunosuppressive or antimitotic drugs)
  • Current pregnancy or breastfeeding
  • Current substance misuse
  • Recent (< 3 months) use of psychotropic drugs
  • Participant in a psychological or medical study involving the use of medication within the last 3 months
  • Participant in another study using the same / a similar battery of cognitive / emotional tasks in the last 3 months
  • Current smoker of more than 5 cigarettes per day
  • Dyslexia (given the nature of the computer tasks)
  • Lactose intolerance (placebo is composed of lactose capsules)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03768557

Layout table for location information
United Kingdom
Warneford Hospital
Oxford, Oxfordshire, United Kingdom, OX3 7JX
Sponsors and Collaborators
University of Oxford

Layout table for additonal information
Responsible Party: University of Oxford Identifier: NCT03768557     History of Changes
Other Study ID Numbers: R50651/RE001
First Posted: December 7, 2018    Key Record Dates
Last Update Posted: April 18, 2019
Last Verified: November 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
Layout table for MeSH terms
Anti-Bacterial Agents
Anti-Infective Agents