Around a quarter of people experience depression at some point in their lives, two-thirds of whom are women. Each year more than 11m working days are lost in the UK to stress, depression or anxiety and there are more than 6,000 suicides. The impact of depression on individuals, families, society and the economy is enormous.
Front-line therapies usually include medication. All the commonly prescribed antidepressants are based on “the monoamine hypothesis“. This holds that depression is caused by a shortage of serotonin and noradrenaline in the brain. Existing antidepressants are designed to increase the levels of these chemicals.
The first generation of antidepressants were developed in the 1950s and a second generation came in the 1980s. Products such as Prozac and Seroxat were hailed as “wonder drugs” when they first came onto the market.
In the roughly 30 years since, these kinds of drugs have come to look tired and jaded. Patents have expired and there are doubts about their efficacy. Some scientists even argue the drugs do more harm than good.
Broken model
There has been no third generation of antidepressants. This is despite there having been moon-landing levels of investment in research. The antidepressant discovery process that gave rise to the earlier drugs is clearly broken. It is also apparent that this process had never worked that well, since the only real improvements over the previous 60 years were a reduction of side-effects.