Major Depressive Disorder Clinical Trials in United Kingdom

Research suggests that only a subset of individuals with major depressive disorder (MDD) may benefit from anti-inflammatory treatments: those who have C-reactive protein (CRP) ≥3 mg/L, a commonly used threshold for "low-grade" inflammation. The emerging link between metabolic and immune abnormalities in MDD suggests that individuals with comorbid obesity and MDD are a subset of people who could particularly benefit from anti-inflammatory treatment. The coexistence of obesity and MDD has been shown to amplify the risk of clinically elevated CRP levels (≥3mg/L). Therefore, people with comorbid obesity, MDD, and CRP ≥3mg/L could be an ideal target population in future randomised clinical trials (RCTs). However, investigation into the feasibility and acceptability of inflammation-targeting treatment in this population is needed first. Meta-analyses identify minocycline (a tetracycline antibiotic that can cross the blood-brain barrier) as one of the most effective inflammation-targeting medications with antidepressant effects. Minocycline can safely be used long-term at dosages of up to 200mg per day and has low tendency to lead to antibiotic resistance. A pilot RCT of minocycline found a large effect size (Cohen's d=0.98, p\<0.001) for the reduction of MDD symptoms compared with placebo. This effect size was even larger (Cohen's d=1.5, p\<0.005) in another RCT using minocycline when considering only participants with CRP ≥3mg/L. One mechanism through which minocycline could ameliorate MDD symptoms appears to involve the activation of indoleamine 2,3-dioxygenase (IDO), which leads to an increase in the expression and function of the serotonin transporter. Studies exploring this anti-inflammatory effect in MDD demonstrate that minocycline indeed can inhibit IDO. Another pathway through which minocycline could ameliorate MDD symptoms is through the reduction of inflammation at the central level. Minocycline has been shown to reduce microglia activation in preclinical models. Previous literature reports an impact of neuroinflammation on white matter microstructure and brain structure in patients with MDD and in individuals with obesity. Minocycline's effect on white matter structure and myelination has not yet been investigated in humans in vivo. Investigating whether neuroimaging biomarker candidates associated with neuroinflammation could be detected in this study design is needed. Read Less

Over 28 million people suffer from current depressive disorder in the European Union. Major depressive disorder (MDD) is one of the most common psychiatric illnesses. The symptoms cause clinically significant distress or impairment in social, occupational, and other important areas of functioning. To treat MDD, there are several antidepressants available and prescribing medication is a process of trial-and-error. Guidelines do not explicitly advise on the order in which antidepressant medication should be prescribed. The choice of antidepressant should be tailored to the patient, while involving the patient in the decision-making process. In general, the choice for the first- and second-line treatment will be a second-generation antidepressant. Recently, esketamine nasal spray (intranasal (IN) administration) was approved for patients with treatment-resistant MDD (TRD). A patient is diagnosed with TRD when having used two antidepressants in sufficient duration and adequate dose without sufficient effect. TRD is associated with a negative impact on quality of life, higher risk for hospitalisations and suicide, comorbidities, poorer social and occupational functioning and a high carer burden. The efficacy of intranasal use of esketamine has been demonstrated in MDD subjects with treatment-resistant symptoms but also in subjects with non-treatment resistant depression, and is approved by the FDA and EMA as a third-line treatment. Besides the registered esketamine nasal spray, which is not available in all countries to all patients because of the high costs, off-label utilization of (es)ketamine infusions (IV) is growing extensively over time to treat TRD. Research conducted so far indicates an unequivocal initial substantial response to (es)ketamine IV in MDD populations, regardless of whether or not patients suffer from treatment resistant MDD. However, until now, there has not been a study investigating this in a sufficiently large population. This may be a unique opportunity to potentially prevent patients progressing into a treatment resistant illness stage. The potential implications of the results of the current study are the prevention of unnecessary trials of ineffective treatments, reducing subject burden substantially, as well as a reduction of healthcare and societal costs. Read Less

This study will test whether it is feasible to conduct a clinical trial of mirtazapine (an antidepressant tablet) in patients who have both depression and inflammatory bowel disease (IBD). The study design is a randomised controlled trial (a study in which people are allocated by chance to receive different interventions). The trial will compare mirtazapine against a placebo (dummy) tablet in 76 patients with both depression and IBD. The investigators will recruit outpatients aged 18 or over with a diagnosis of any IBD attending gastroenterology clinics. Either in person or remotely, patients will complete a brief screening questionnaire for depression. Those scoring positive for depression will be invited for a 15-minute interview for clinical depression. Those with clinical depression will be invited to take part. Participants will be randomly allocated by a computer to take either 1) mirtazapine tablet once at night for 12 weeks; or 2) placebo (dummy) tablet once at night for 12 weeks. The study is 'blinded', meaning neither patients nor the study team will know which medication they are taking. Throughout, participants will be able to access other treatments for depression, such as talking therapies. The investigators will measure how many people join the study; how many remain in the trial; how many complete treatment; how many tablets people take; and assess overall acceptability of the trial. Participants will complete brief questionnaires to measure their mental health and IBD symptoms after 4 weeks, 8 weeks, 12 weeks and 16 weeks. Participants will also provide blood samples and faecal samples to measure inflammation. If successful, this trial will support an application for a larger version of the study. Read Less

Clinical depression often includes a pessimistic view of things which have happened in the past and an impairment in the ability to experience pleasure or looking forward to things. A licensed drug called ketamine affects the levels of glutamate, a chemical messenger in the brain, and has been used as a treatment particularly for depression which hasn't got better with other types of medication. Glutamate plays a role in learning and memory so the investigators are interested in understanding how ketamine can affect how people with depression remember past negative and positive memories and how they experience reward. The investigators are conducting a study in depressed participants who did not improve with the standard antidepressant treatment to expand our understanding on how ketamine can influence memory, the way people understand emotions and learn from rewards and punishments. Study participants will undergo medical and psychiatric health screening, drug administration (ketamine or saline), questionnaires and computer tasks before and after the administration of the study drug, and an MRI scan after administration of the drug. MRI is a type of brain scan that allows us to see how the brain responds during for example memories of things which have happened in the past. This project will help us understand how NMDA antagonists may work in depression. Read Less

The aim of this Phase 2a study in patients with MDD is to assess safety and tolerability and preliminary antidepressant efficacy. Read Less

The aim of this Phase 2a study in patients with MDD is to assess safety and tolerability and preliminary antidepressant efficacy. Read Less