‘ACCIDENT. Always regrettable.’ —Flaubert
The US National Institute for Mental Health (NIMH) said the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders) had so many problems we effectively need to tear it up and start again. The way forward, it said, is a new research programme to discover the brain problems that underlie mental illnesses.
That research is now taking off. The first milestone came earlier this year, when the NIMH published a list of 23 core brain functions and their associated neural circuitry, neurotransmitters and genes – and the behaviours and emotions that go with them (see “The mind’s 23 building blocks”). Within weeks, the first drug trials conceived and funded through this new programme will begin. […]
Criticism of psychiatry has been growing for years – existing treatments are often inadequate, and myriad advances in neuroscience and genetics have not translated into anything better. Vocal opponents are not confined to the US. Last week, the new UK Council for Evidence-based Psychiatry launched a campaign claiming that drugs such as antidepressants and antipsychotics often do more harm than good.
What’s more, many suspect that commonly used labels, such as depression and schizophrenia, merely group together people sharing some superficial symptoms, when their underlying brain disorders are quite different.
Genetic studies, for instance, suggest that schizophrenia and bipolar disorder, supposedly distinct conditions, involve mutations in many of the same genes. And diagnostic confusion between the disorders is common. […]
So what do the mind’s 23 building blocks consist of? The best mapped-out anatomically is the brain’s fear circuitry, thanks to years of scaring volunteers as they lie in fMRI scanners. This system is probably involved in phobias and post-traumatic stress disorder.
Another is the related circuitry that deals, not with present danger, but with vaguer fears that something bad might happen in future. “That circuit is very relevant to rumination and anxiety,” says Cuthbert.
Another five neural systems are components of the brain’s reward circuitry, which is active when we find something pleasurable – like eating or sex – and drives us to repeat the experience. These can malfunction when people are addicted to drugs or alcohol.
The reward system, says Cuthbert, is very powerful because one of the most important things that organisms need to learn is to seek out things like food and water. “Drug abuse hijacks that system so the cues create urges that are very hard to resist,” he says.
