Biochemical theory

There was a problem with this first version of the biochemical theory of depression. Iproniazid was not the only drug that had been reported to be effective as an antidepressant. Imipramine, the drug that had been tested by the Swiss psychiatrist Roland Kuhn, seemed to have similar effects. But imipramine is not an MAOI it does not inhibit the destruction of neurotransmitters in the synapse. So if antidepressants worked by inhibiting monoamine oxidase, why was imipramine effective How could its apparent effectiveness be reconciled with the chemical-imbalance theory ... 

When Schildkraut introduced the monoamine theory of depression, he admitted that there was little direct evidence for it. Instead, it was based on the supposed effectiveness of antidepressant medication and the mistaken belief that reserpine makes people depressed. Schildkraut acknowledged that Most of this evidence is indirect, deriving from pharmacological studies with drugs such as reserpine, amphetamine and the monoamine oxidase inhibitor antidepressants which produce affective changes. 21 A half-century has passed since his chemical-imbalance theory of depression was introduced, and the presumed effectiveness of antidepressants remains the primary evidence in its support. But as we have seen, the therapeutic effects of antidepressants are largely due to the placebo effect, and this pretty much knocks the legs out from under the biochemical theory. 

The biochemical theory of depression is in a state of crisis. The data just do not fit the theory. The neurotransmitter depletion studies that I described earlier in this chapter show that lowering serotonin or norepinephrine levels does not make most people depressed. When administered as antidepressants, drugs that increase, decrease or have no effect on serotonin all relieve depression to about the same degree. And the effect of anti-depressants, which was the basis for proposing the chemical-imbalance theory in the first place, turns out to be largely a placebo effect. 

There are a number of different structural types of CNS depressants. Their modes of action are putative, that is, they are generally unknown but we have some indirect evidence of mechanisms. Much of what is known arises from their observed effects and not necessarily from direct experimental evidence. In fact, some of the drugs we will discuss, such as the opiates, have been around for millenia, long before any biochemical theories concerning their actions were conjectured. In the case of the opiates, it was their known effects which led researchers like Solomon Snyder and Candace Pert to theorize about the existence of natural (endogenous) opiate neurotransmitters, which they eventually found in the lab. The PBS NOVA segment entitled "The Keys to Paradise" and available in the Cal Poly libray describes the discovery of endogenous opiates. 

Breggin, P. (1991c). Toxic psychiatry Why therapy, empathy and love must replace the drugs, electroshock and biochemical theories of the new psychiatry. New York St. Martin s. 

Electroshock and Biochemical Theories of the New Psychiatry (1991) Beyond Conflict From Self-Help and Psychotherapy to Peacemaking (1992) Talking Back to Prozac (coauthor Ginger Breggin) (1994)... 

Baker GB, Dewhurst WG. Biochemical theories of affective disorders. In The Pharmacotherapy of Affective Disorders Theory and Practice. Dewhurst WG and Baker GB, eds. 1985. Croom Helm Ltd., London, pp. 1-59. 

P. Politzer and V. M. Estes, Jerusalem Symp. Quantum Chem. Biochem., Catal. Chem. Biochem., Theory Exp., 305 (1979). 

Biochemical theory based on our knowledge of the rates of reaction of biological catalysts (enzymes) suggests, however, that the time from the development of protometabolism to the formation of the first oligonucleotides (nucleic acids) may in fact have required only a few thousands of years, at most a few tens of thousands of years, rather than the hundreds of millions of years implied from the geochemical data. A shorter period for the evolution of life means that there would not have been the same necessity for inordinately long periods of environmental stability and also that evolution could have been attempted in different places at different times. 

Its methods and findings unify our knowledge of the mechanisms of life biochemical theories approach questions of the origins of life on earth biochemical techniques help to explain the interactions of viruses with their hosts, and to tailor-make the vital drugs in the pharmacologists armoury. 

R. Breggin, M.D., who has written, among other books on the subject. Toxic Psychiatry Why Therapy, Empathy, and Love Must Replace the Drugs, Electroshock, and Biochemical Theories of the New Psychiatry . Breggin sees the medicines themselves as the cause of stiU other mental dysfunctions, especially over the long term. 

Extensive reviews dealing with the pharmacology and biochemistry of the psychotomimetic compounds and with biochemical theories of schizophrenia , have recently been published. 

Neurotransmitters are not only chemical messengers for the nervous system, they may also be partly responsible for our moods. A simplified biochemical theory of mental illness is based on two amines found in the brain. The first is norepinephrine (NE). When an excess of norepinephrine is formed in the brain, the result is a feeUng of elation. Extreme excesses of NE can even induce a maific state, while low NE levels may be a cause of depression. 

The second amine often associated with the biochemical theory of mental illness is serotonin. Like norepinephrine, it also functions as a neurohansmitter. Serotonin is produced in the body from the amino acid tryptophan ... 

Name the two amines often associated with the biochemical theory of mental illness. 

This work on the inhibition against E. coli PDHc by sodium O-methyl acetylphosphonate 1-1 exemplified a more modem approach to the design of specific enzyme (PDHc El) inhibitors. Kluger et al. had established a new standard to promote the design and smdy on PDHc inhibitors using a biochemical theory. 

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