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expert reaction to taurine reducing symptoms of psychosis – unpublished poster presentation from the International Early Psychosis Association (IEPA) meeting in Milan

An unpublished poster presentation presented at the International Early Psychosis Association (IEPA) meeting in Milan has reported the use of the chemical taurine as able to reduce the symptoms of psychosis.

 

Dr Michael Bloomfield, Clinical Lecturer in General Psychiatry and Honorary Senior Clinical Research Fellow, Division of Psychiatry, UCL, said:

“Schizophrenia is a potentially devastating mental illness in which people can have frightening experiences that are not based in reality called episodes of psychosis.  Whilst many people’s distressing experiences can improve by taking medicines which work by reducing the effect of the brain chemical dopamine, there are people who experience unwanted side-effects and/or do not get better with these medicines.  It is therefore essential that we develop new treatments for the millions of people suffering with schizophrenia worldwide.

“This new researched which is being presented at a conference has not yet undergone scientific peer review, and so the results of the study, whilst interesting, should be treated with a degree of caution.  Whereas all existing treatments in psychosis work by reducing dopamine, taurine is suggested to work by acting on different brain proteins involved in other chemical systems.  It is exciting that this new research finds that adding on taurine to existing treatment was associated with improvements in symptoms and the authors report this to appear safe.  I must emphasize that this study still needs to publish a full statistical analysis and undergo the usual scientific review process before we can decide on the next steps.  If the results of the study are upheld following thorough statistical analysis and peer review, then further and larger randomized controlled trials using taurine may be justified.  It is far too early to advise patients to start taking taurine supplements and no one experiencing psychosis should change their medicines without discussing this with their psychiatrist or GP first.  In particular, it would not be advisable to take alternative sources of taurine, such as those found in energy drinks like Red Bull, given that these drinks also contain high amounts of sugar and caffeine.  This is because people with schizophrenia may be at particularly high risk of developing diabetes later in life and drinking too much caffeine is generally accepted as not being particularly helpful for our mental health, especially in terms of our sleep and anxiety levels.

“Of scientific interest, one of the potential causes of schizophrenia is thought to perhaps involve a lowering of functioning of a protein called the NMDA receptor.  This is interesting because taurine may also reduce the functioning of this protein, which appears to be counter-intuitive and might shed further light on what causes the illness and therefore other potential new avenues for future research into new treatments.”

 

Prof. Stephen Lawrie, Head of Psychiatry, University of Edinburgh, said:

“This is a preliminary piece of work which people should not over-react to! As a poster, presented at a conference, many of the details of the study will not be clear until the study is published in a journal. There are the usual questions about how robust the trial design was – in particular was allocation to taurine random, not biased and done blind? There is also an obvious concern that about one-third of trial participants dropped out before the end of the study – which means that the results may not hold in routine practice.

“Further, there is a wider point that existing antipsychotic drugs are actually very effective against positive psychotic symptoms (those symptoms which most people do not normally experience but are present in people with schizophrenia). From that perspective, taurine’s effects on depression in first episode psychosis are perhaps more interesting.

“Those reservations aside, the more therapeutic interventions available for any condition the better. These interesting preliminary results probably do merit further study but based on this evidence people should NOT start self-medicating with Red Bull.”

 

Dr Ravi Das, Research Associate in Psychopharmacology, UCL, said:

“Red Bull isn’t just taurine. It contains a load of caffeine and either sugar or sweetener as well, so you can’t extrapolate the effects of taurine (a single amino acid) to Red Bull (a mass-produced soft drink). This is the same logical fallacy as justifying drinking loads of red wine based on the fact that it contains some beneficial compounds like antioxidants and resveratrol. Taurine may be a useful add-on for young individuals with psychosis, but it doesn’t mean they should be drinking Red Bull, especially as they’d need to drink 4 cans a day to get the equivalent dose of taurine used in the study.

“The study is a registered clinical trial, where participants have been independently randomised to groups and the drugs given in a double-blind, placebo controlled manner to reduce expectancy effects and bias in the ratings of psychosis. This is important, because the Brief Psychiatric Rating Scale (BPRS) is administered by a clinician, so treatment-favouring bias could easily slip in. It looks well designed and will have undergone quite rigorous checks and management. As there’s currently only the information available in the poster, it’s unclear how ‘successful’ the blinding was. That is to say, we don’t know how frequently patients/clinicians correctly guessed which condition participants were in.

“I don’t think a poster is necessarily ‘less robust’ than a paper. Presumably the findings will stand in the final paper. It will have undergone less rigorous review however and, being a poster, the information therein is necessarily less complete (I had to look up the trial on the clinical trials register to find out about the blinding procedure, for instance). There are a few things that stand out, though:

The poster does not report either what statistical tests were used, or effect sizes, just p values and confidence intervals. It does not say whether these p values were corrected for Type 1 error (i.e. false positive rate).

All effects are expressed as ‘change from baseline’ scores, which always makes me slightly wary, because we don’t know if the groups differed in psychosis symptoms, depression etc. at baseline, or how much the drug effect was dependent upon baseline levels of these factors. The taurine group seem to have had around 20 days more in treatment and were on a lower dose of antipsychotics overall, for instance.

There are no error bars on the graphs, so we don’t know anything about the variability in treatment response

The effects of taurine on depression and global functioning are just under the ‘magic’ 0.05 threshold. I’m not implying that there was any p-hacking going on, but we see more of this in the drugs literature than we should.

“There’s good rationale for taurine being beneficial in schizophrenia and psychosis. It is an amino acid that is abundant in the body. It is ‘neuroprotective’ against the damage in neural cells caused by abnormal glutamate signalling, which is heavily implicated in psychosis and schizophrenia. It’s very well tolerated, which is one of the big draws of this study, as this is much more attractive as a treatment option than other medication with lots of side effects.

“The effects weren’t huge, judging by the graphs, but as I mentioned, no effect sizes or error bars were given in the poster so it’s hard to tell.  It seems as though there’s a drop of 3 points in psychiatric symptoms overall, 0.5 to 1 point in psychosis specifically and depression score, which is relatively small compared to conventional antipsychotics. However, it’s important to remember that this is a low-risk, low-side effect, cheap add-on treatment. It’s possible that larger effects might have emerged over a longer time frame by preventing ongoing neural damage, but we can’t tell from the data.”

 

 ‘Phase II, double-blind, randomised, placebo-controlled study of adjunctive taurine in first-episode psychosis’ by name of O’Donnell et al. presented at the IEPA meeting. 

 

Declared interests

Others: None declared

Dr Das: “I have no conflicts of interest. I’m currently funded entirely by an MRC grant and a part-time statistics tutoring job!”

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