Changing brains: why neuroscience is ending the Prozac era
The starkest indication that drugs are increasingly being thought of as yesterday’s cutting-edge comes from the little mentioned fact that almost all the major drug companies have closed or curtailed their drug discovery programmes for mental and neurological disorders. The realisation that there has been little in the way of genuine innovation since the major classes of psychiatric drugs were discovered in the 1950s has made future sales look bleak. New drugs have regularly appeared since then, often with fewer side effects, but most are little better in terms of effectiveness.
This is largely because these drugs tend not to be very specific in their effects on the brain. For example, the medication fluoxetine (better known as Prozac) alters levels of the neurotransmitter serotonin in brain networks related to mood, but it has the same effect in brain networks involved in sexual response, leading to the common side effect of difficulty with orgasm. The pharmaceutical holy grail has been to develop drugs that are more selective in their effects, but this multibillion dollar dream has largely been ditched by Big Pharma as too difficult.
In its place is a science focused on understanding the brain as a series of networks, each of which supports a different aspect of our experience and behaviour. By this analysis, the brain is a bit like a city: you can’t make sense of the bigger picture without knowing how everything interacts.
Perhaps more surprising for some is the explosion in deep brain stimulation procedures, where electrodes are implanted in the brains of patients to alter electronically the activity in specific neural circuits. Medtronic, just one of the manufacturers of these devices, claims that its stimulators have been used in more than 100,000 patients. Most of these involve well-tested and validated treatments for Parkinson’s disease, but increasingly they are being trialled for a wider range of problems. Recent studies have examined direct brain stimulation for treating pain, epilepsy, eating disorders, addiction, controlling aggression, enhancing memory and for intervening in a range of other behavioural problems.
Read the full article at: theguardian.com