The Taste-Mood Diagnostic Study
The Taste-Mood Diagnostic Study
The study will be looking at whether a taste test device can be used as a diagnostic aid for
 depression. Taste tests will be carried out before and after first use of an antidepressant
 (prescribed by the patient's GP) and then again a month later a further taste test will be
 conducted. The results of these tests will be assessed to see if they correlate with the
 outcome of validated mood questionnaires carried out at the first and second visits.
Research shows a clear link between taste sensitivity and depression, based on chemistry
 shared by the tongue and the brain. (Heath, T.P., Melichar, J.M., Nutt, D.J., Donaldson L.F.
 (2006) Human taste thresholds are modulated by serotonin and noradrenaline). The aim of this
 study is to investigate the use of a taste test in the diagnosis of depression and to predict
 drug effectiveness.

 A device is being developed to automate the taste test with different concentrations of salt,
 sweet, bitter and sour solutions. A test is carried out before and after ingesting a probe
 drug (first prescribed antidepressant) to assess change in taste. Standard validated
 questionnaires are used to assess mood on the day the first antidepressant is ingested and
 one month later.

 The first 30 participants will have taste tests conducted out not only via the device
 described above, but also via a paper flow chart which similarly determines the order in
 which taste solutions are presented to the participant to determine taste acuity.

 The study is a single centre, open label study using the patient's prescribed antidepressant
 as a probe with the primary objective of replicating previous results obtained, without the
 use of a device, and using paroxetine. The study is powered to test 240 patients with the
 provision built in to the protocol for an interim analysis after 120 patients have been
 tested. This will lead to the generation of a robust diagnostic algorithm.

 Patients will be followed up for repeat taste testing after 28 days (±7 days) of usual
 clinical care, and follow up questionnaires will be completed at that visit. Patients will be
 asked to complete a feedback questionnaire about their user experience and satisfaction with
 treatment alone.
Inclusion Criteria:

 -  Patients with a diagnosis of previously untreated Major Depressive Disorder (MDD) of
 at least 3 weeks duration or new or recurrent MDD untreated before this episode
 (patients who have previously received treatment for MDD must have stopped taking
 antidepressant medication at least six weeks prior to entering the trial);

 -  Patients requiring pharmaceutical intervention as a treatment for MDD;

 -  Not suffering from any significant other mental or physical illness, such as confirmed
 psychosis, or end of life care.

 -  Receiving stable medical therapy for 30 days or longer before screening assessments;

 -  Be willing and able to comply with all visits and study related procedures;

 -  Not infected with coronavirus or needing to self-isolate

 -  Understands the study requirements and the treatment procedures and is able to provide
 written informed consent.

 Exclusion Criteria:

 -  Already on antidepressant medication;

 -  Known or suspected hypersensitivity or intolerance to any probes, or any of their
 excipients;

 -  Relevant history or presence upon clinical examination, of cardiac, ophthalmologic,
 gastro-intestinal, hepatic, or renal disease or other condition known to increase risk
 of side effects of the probe drugs. This exclusion criterion is determined by the Site
 Investigator;

 -  Have a history or presence of neurological or confounding psychiatric conditions (such
 as stroke, traumatic brain injury, epilepsy, space occupying lesions, multiple
 sclerosis, Parkinson's disease, vascular dementia, transient ischemic attack, or
 schizophrenia),

 -  Patients with a diagnosis of chronic pain.

 -  Participation in another trial concurrently or within 30 days preceding enrolment that
 is deemed to interfere with this trial;

 -  Patients who are pregnant, or who are likely to become pregnant, will be excluded from
 the trial, as will breastfeeding mothers;

 -  Patients using supplements containing psychoactive herbs (for example St Johns Wort or
 5-HTP (5-Hydroxytryptophan, also known as oxitriptan);

 -  Patients regularly using psychoactive stimulants and recreational drugs (for example
 MDMA (ecstasy/ methyl enedioxy methamphetamine), amphetamine, LSD (lysergic acid
 diethylamide), cocaine);

 -  Patients infected with coronavirus, or who are advised to self-isolate

 -  Patients who are unable or unwilling to comply with study procedures.