08/06/2016 12:26 BST | Updated 09/06/2017 06:12 BST

The Trial and Error Days of Antidepressant Drug Treatment Could Soon Be Over

It is rare in science that a study will show 100% anything. Today this has happened. Scientists at Kings College London have developed a blood test that they say 'accurately and reliably predicts whether people living with depression will respond to common antidepressants'. This could mark a real sea change in antidepressant drug treatment.

The researchers have identified biomarkers in the blood that predict patients' responses to treatment. By measuring these biomarkers, researchers found that patients with high levels of the markers (above a threshold that they set) showed a 100 per cent chance of not responding to conventional, commonly prescribed antidepressants. The study authors said that those who measured below their suggested thresholds could be expected to respond to antidepressants.

Today's findings could mean that people who would not respond well to antidepressants will not have to find out the hard way, being prescribed them as part of a long standing trial and error approach.

I had a chat with Deena who has been through the trial and error prescription process of antidepressant drug medication:

"I've tried 8 different drugs over the last 6 years, in the first 2 years it was completely trial and error. The impact of that meant that the early days were really hard. Every time I was put on a new drug I'd be left in a kind of limbo thinking will it work, will it not. When they don't work I think that's when things start to crash even more because I felt that things would never get better and that no one knew how to help ease the symptoms.

"Had this blood test been around back then it probably would have given me more hope and reduced the amount of time I spent in and out of hospital as a result of not responding well to the drugs.

"It's not just drug therapy that's going to work, one of the most helpful things for me has been a form of behavioural psychotherapy called DBT, it's given me the coping strategies that I use every day now. Ultimately the success of any drug will be influenced by other factors including compliance and acceptance of diagnosis, access to therapies and mental health support."

As Deena highlighted, medication is only a small part of the answer in treating mental health problems, something the Mental Health Foundation has also been saying for a long time. There needs to be a much greater focus on providing patients with a wide range of treatments as part of a personalised approach to treatment. Knowing whether someone is likely to respond to medication or not will enable doctors to signpost effective treatments not involving drugs, like talking therapy and/or mindfulness, as soon as possible.

We will need to see further human clinical trials as the current sample size was relatively small, involving 140 participants. If results released today are echoed in future trials, there could be a real sea-change in treatment. New blood tests could provide doctors with a new tool facilitating a more personalised approach to treatment and moving people away from medication that doesn't work for them. Today could mark the beginning of the end of the trial and error approach to antidepressant drug treatment.