Scientists at King’s College London have developed a blood test for identifying the most appropriate drug to treat depression. The research has only been carried out on a relatively small group of 140 volunteers so far, but the results were promising enough to justify moving on to a larger trial to check for the suitability of this method for wider use.

The test looks for whether the patient has inflammation, in which case more intense therapy should be used without the need to try various different antidepressants before finding a useful one. At the moment it is difficult to tell which particular drug would be most effective for the treatment of depression and doctors have to resort to a trial and error method with various drugs and dosages. Antidepressants can have some side effects, with more aggressive drugs having more severe ones.

The most c o m m o n l y prescribed drugs are SSRIs, which the scientists have found are less effective when used to treat patients with high levels of inflammation markers. The blood test looks for macrophage migration inhibitory factor (MIF) and interleukin-1beta, which are signs of inflammation. The biological mechanisms involved in how drugs work to treat depression can be affected by inflammation, reducing the effectiveness of the treatment.

The lead researcher, Professor Carmine Pariante, said: “We would not want to go in prescribing too much medicine if it’s not necessary, but we would want to escalate people sooner rather than later if they need it.”

A representative from Mind, the mental health charity, pointed out that “different people will find different treatments help to manage their mental health”. He also mentioned the importance of other types of treatment, saying: “What is most is important is that people have the knowledge needed to access the treatment that works for them, whether this is medication, or alternatives such as talking therapies, or a mixture of both.”

UEA student Matt said: “Any development of any drug that helps to reduce the need for trial and error is promising. However, I don’t think it should take away from the non-biological factors of treating depression. There has to be a focus on the causes of depression not just the symptoms.”