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Ciaran Regan


Book review by Anthony Campbell. Copyright © Anthony Campbell (2001).

The use of drugs to alter consciousness is probably as old as humanity. although the range of substances available for the purpose increased markedly in the twentieth century, and so too did our understanding of how they act on the brain. We have moved a considerable distance from the situation satirized in Molière's "Malade Imaginaire", in which the reason why morphine induces sleep is said to be that it contains a dormitative principle. This short book provides an account of psychoactive drugs for the general reader.

Caffeine-related substances (tea, coffee, cocoa, cola) are of course familiar in the West, and so too is nicotine in the form of tobacco. Another nicotine-like substance is arecaidine, the active principle of betel nut, which we generally think of as an Indian recreational drug (it even figures in religious rites there). However, Regan tells us that it spread to India from other areas ranging from East Africa to Polynesia. In fact, "betel nut" is a misnomer; the arecaidine comes from palm seeds wrapped in the leaves of a vine called betel. Regan summarizes what is known about these substances as well as narcotics and alcohol. One area he doesn't touch on is the "learned" response to alcohol; there is a lot of evidence to show that how people behave when drunk is to a considerable extent the result of expectations within their culture.

Regan traces the 20th-century development of pharmacological treatments for depression, anxiety, and schizophrenia. The problem with these is that, although mainstream psychiatric opinion now regards all such psychiatric disorders as due to brain disease, we don't know the mechanisms in any detail. Moreover, the drugs in use today to treat these disorders are essentially the same as those discovered in the mid-1950s. The so-called "second generation" drugs used as antidepressants continue to rely on blocking serotonin or noradrenaline uptake (or both); drugs used to treat schizophrenia are mainly dopamine antagonists although some are thought to have an additional action at serotonin receptors. But the underlying assumption is that dopamine overactivity is the basis of schizophrenia and that serotonin or noradrenaline dysfunction is the cause of depression, and perhaps mania, and these hypotheses are inadequate. Regan mentions possible genetic and evolutionary explanations for these disorders but doesn't develop the idea in any depth.

There has always been a strand of opinion that favours the use of drugs to expand consciousness and even to provide mystical or religious illumination; modern pharmacology has provided us with LSD. The mechanisms by which so-called psychedelic drugs produce their effects is still unclear. Drugs such as LSD, psilocybin, and mescaline are structurally fairly similar to the brain neurotransmitters noradrenaline and serotonin and these drugs act on an area of the brain stem called the raphe nucleus. If rats are given LSD or psilocybin the cells in their raphe nucleus stop firing; this is interesting because that region of the brain regulates the dreaming phases of sleep. Does this mean that these drugs produce a kind of waking dream state? This hypothesis has appealed to many researchers but there are difficulties with it. For example, mescaline does not act on this brain region and other drugs, which do act there, don't have psychedelic effects. Another suggestion is that psychedelic drugs act on the reticular activating system (of which the nucleus raphe magnus is a part) to create hyper-arousal through a patterned release of noradrenaline throughout the brain. This might lead to a chaotic state of brain functioning in which, for example, sounds are perceived as colours. But Regan is dismissive of the notion that psychedelic drugs can provide genuine mystical illumination.

Regan is optimistic about the future of psychopharmacology. Our increasing understanding of genetics, he believes, will allow us to design drugs that will precisely alter brain function in a way that is individually adapted to each patient. The days of humanistic psychology, which he equates with shamanism, are over, he believes. He may be right about this, although the suggestion won't be welcome to everyone, and he glosses over the question of how our knowledge of genetics will be translated into an understanding of the biochemical mechanism of depression and schizophrenia.

%T Intoxicating Minds
%A Ciaran Regan
%I Weidenfeld and Nicolson
%C London
%D 2000
%G ISBN 0-297-84287-0
%P x + 164 pp
%K pharmacology

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