Drugs are not specific enough either, and they are much slower than the natural operating speed of the brain. Electrical stimuli cannot meet this challenge because electrodes are too crude a tool: they stimulate all the circuitry at their insertion site without distinguishing between different cell types, and their signals cannot turn off neurons with precision. In a 1979 Scientific American article Nobel laureate Francis Crick suggested that the major challenge facing neuroscience was the need to control one type of cell in the brain while leaving others unaltered. And psychiatric treatments have historically been largely serendipitous: helpful for many but rarely illuminating, and suffering from the same challenges as basic neuroscience.
The ruling paradigm of psychiatric disorders-casting them in terms of chemical imbalances and altered levels of neurotransmitters-does not do justice to the brain's high-speed electrical neural circuitry. By extension, we also do not know how the brain's physical failures produce distinct psychiatric disorders such as depression or schizophrenia. Because of that complexity, neuroscientists lack a deep grasp of what the brain is really doing-of how specific activity patterns within specific brain cells ultimately give rise to thoughts, feelings and memories. It is an intricate system in which tens of billions of intertwined neurons-with multitudinous distinct characteristics and wiring patterns-compute with precisely timed, millisecond-scale electrical signals, as well as with a rich diversity of biochemical messengers. In other words, we need new technology.ĭeveloping appropriate techniques is difficult, however, because the mammalian brain is beyond compare in its complexity. But as philosopher of science Karl Popper might have said, before we can find the answers, we need the power to ask new questions. Clearly, we need new answers in psychiatry. Despite the enormous efforts of clinicians and researchers, our limited insight into psychiatric disease (the worldwide-leading cause of years of life lost to death or disability) hinders the search for cures and contributes to stigmatization.
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