Archive for the ‘Neuroscience research’ Category

It was the 1980’s, and  I had reached the point where my credibility as an anthropologist demanded I do field work. It would be something on drugs of course. But what exactly?

I decided to formulate some test hypotheses that would cover both social and biological aspects of drug consumption. My research into prehistoric drug use together with findings from ‘current’ neuropsychopharmacology (i.e. from the 1970’s -1980’s period)  would suggest these hypotheses. The  fact that I possessed the rare combination of both pharmacy and anthropology qualifications meant I had the chance to make a worthwhile contribution to an important issue of my time.

I ran into a problem straight away. I could find no references in popular culture of the 1980’s  to the neuroscience concept that drug addiction is a ‘relapsing’ brain disease like schizophrenia or diabetes; that even the though the initial act of consumption is entirely voluntary   brain disease develops over time and that without formal medical treatment, compulsive drug craving, seeking, and consuming take over (Leshner, 1990).

This  neuroscience discovery is, and remains, a gloomy finding. Al Gore might well think of it as another ‘Inconvenient Truth’  like ‘Climate Change’. Could I have been wrong in evaluating so highly the neuroscience research on psychoactive substances ? After all, I am a pharmacist not a pharmacologist. So it was possible the neuroscience findings held flaws I had missed.

Nevertheless, great synergy exists between patterns of prehistoric drug consumption and the neuroscience model of drug effects on individuals. A few examples make the point:   All else being equal, if human biology is capable of producing compulsive drug seeking and consumption, then you would expect to find drug plants among the earliest plants prehistoric people cultivated. Similarly, drugs should be  among the earliest items traded between different environments and populations. Finally, prehistoric populations with regional monopolies on drugs should demonstrate political and social changes forced upon them by the compulsive drug seeking from their addicted non-drug producing neighbours. See my earlier blogs for examples:

A. I. Leshner, “Science-Based Views of Drug Addiction and Its Treatment,” Journal of the American Medical Association 282 (1999): 1314­1316 (http://jama.ama-assn.org/issues/v282n14/rfull/jct90020.html

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Knowledge is often slow to permeate throughout the public domain; sometimes it never does. What would be the result with the neuroscience research? The ideas that drug use and drug-seeking are biologically normal and that they result from initial contact between consumption of a psychoactive substance, and a seductive evolutionary process in consumers’ brains, may be too novel and too consequential for easy digestion. However if the neuroscience model were to be fully accepted and promoted, there would be significant losers. These would be the powerful professional groups and government departments currently supporting the belief that it is the weak, the socially disadvantaged, and the psychopath who turn to drug use/abuse for relief. This would not be the greatest concern however.

In his valedictory to C.R Schuster, the latter’s lab colleague and fellow scientist William Woolverton PhD., (July 2011) claimed that animal drug choice issues became his (Woolverton’s) continuing intellectual challenge and pleasure. However, he and others have been ‘bedeviled’ ever since by the question raised by animal drug choice research: does free will exist or not? I mention this story because I think this will be a common reaction to the neuroscience model of drug use/abuse.

For millennia, peoples, societies and religious sects have debated whether individuals make free choices about their lives without the interference of Gods, or Fate, or other external influences. Today, this issue seems dormant. Nevertheless, many of our significant cultural constructions, like religion, moral authority and the legal system, stand upon the concept that individuals have free will.  It is difficult to see how these could continue to be compatible with accepting the biological basis of drug addiction.


To date, my posts about prehistoric drugs have roughly followed the time sequence in which these interests absorbed my attention. My next step was planning my fieldwork. Traditionally in anthropology, novices best prove their abilities by living unsupported in the toughest community they can stomach. Naturally it must also be relevant to your hypotheses. Mine was based on inferences from pituri and the neurological model of drug abuse. So I needed   an isolated drug using community that might serve as an ethnographic model as close as possible to a prehistoric community.

I do intend to include an account of this field work in this blog because it is very relevant. However I (or rather my shell) is becoming very aged and I feel I might not be able to finish it.  So, my next post will leave you with a 2013 account of what I see as the current situation with the neurological model of drug use.



Woolverton, W. (2011). A Tribute to Charles Schuster, PhD. Psychopharmacology and Substance Abuse e Newsletter, July.


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An example of how excessive [drug] behavior occurs might be provided by the socioeconomically deprived ghetto youngster who becomes involved with heroin use through peer pressure and finds such use an acceptable means of alleviating negative personal feelings (anxiety, insecurity, hostility, and frustration) allowing him to ‘feel good’ about himself and his environment.  On the other hand, a middle‑class, Irish Catholic, white male may resort to excessive alcohol use as the preferred vehicle for alleviating his hypophoric state and thus capture the same ‘feel good’ aura (Mule 1984:53).

Keup (1982:10) listed thirty‑seven named, separate, socio-cultural factors involved in “the aetiology  of maladaption [with drugs] the vicious circle of  causative factors involving the family, the youth and  industrial society”. He presents profiles of young drug  abusers, classifying them as either conformists, searchers,  experimenters, gluttons, or dionysians.

I have not written earlier about traditional explanations of drug use and drug abuse because the topic lacked relevance in a prehistoric context. Now I do so. You need to understand the old traditional model to understand the contribution  the neurosciences makes to understanding drug use/abuse. Apart from other issues the latter model is central to my question of whether drug use is result of socio-cultural conditioning or whether it is something rooted deep in mammal brain structures.

Examples of  ’the traditional explanation’ of drug misuse or abuse appear in the introductory quotes. As you can see, social causality and psychological dynamics rate as the villains. These explanations go back at least to the 1940s, possibly much earlier. Not only did individuals adopt these perspectives but so did institutions  ostensibly friendly to drug abusers. The Odyssey House movement refers to clients as ‘sociopaths’ who have never learnt either to trust or to cope.  Even  Alcoholics Anonymous, which is founded upon the concept that  alcohol abuse is a disease, also paradoxically argues that  the blame for contracting the disease rests with the  victim, referring to the “serious character flaws which made  problem drinkers of us” in the first place (Alcoholics  Anonymous quoted in Milam and Ketcham 1985:140). Some scientists imply a criticism of this model  claiming  that,  since 1984  virtually all forms of psychopathology have  been given causal roles in the use/abuse of drugs of psychoactive drugs. The implication here, I believe, is that if the one action is attributed multiple causes, then none of the causes may be correct (Schuster, Renault and Blaine 1979).

 This echoed my own feelings that the traditional explanation of drug misuse or abuse was unhelpful.  And like many people I had one or two heavy drug (alcohol)  users in my social group, and I was saddened by the social stigma they attracted. So I began  following the neuroscience research in the early 1980s through my pharmacy background. I found it exciting. It satisfactorily linked drug chemistry to brain chemistry in arguing that the drugs we consume to alter our moods, soothe our anxieties, explore our creativity, revitalize our courage etcetera, all contain neurotransmitter chemicals identical to neurotransmitters in our brains. The addition of  drug plant neurotransmitter to the neurotransmitters natural to our brain, caused the brain to react by changing the synthesis of the ‘home-grown’ neurotransmitters, or by altering their storage or  release. This was the means by which drug consumption allows individuals to alter their emotions, mood, memory, powers and perceptions of self and others.

The brain’s reward system becomes involved also. As a result, every drug-consuming mammal, whether human or non-human, immediately experiences the urge to continue using psychoactive substances.  Even before any adjustment to the physical body occurs, this form of biological addiction affects all mammals who sample psychoactive substances, whether housewives or CEOs, parrots or bears. With  their first taste of a drug, innocent consumers fall victim to an evolutionary ‘tweak’. The addict is innocent.

Nevertheless not every human individual slips into chronic drug seeking as a result of this exposure. Dr C.R.  Schuster, who in1980 headed the lab for psychopharmacology at  the University of Chicago, noted that a range of cultural and environmental factors may and does limit initial drug use. My accounts of prehistoric drug use reveals some of these environmental factors: for example  continuing supply shortages of pituri and exact knowledge of where it grew, certainly limited use. Socio-cultural restraints shaped consumption too. Aboriginal societies were mostly gerontologies at the time. Powerful older men ensured that life’s goodies went only to powerful older men; and only revered older men knew the secrets of curing Duboisia hopwoodii plants to produce ‘real’ pituri.

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I saw  this new research—animal models of drug abuse together with the existence of a reward structure in the brain—as an entirely novel paradigm, full of promise in a world where the old model was visibly failing.

Below I have summarized the two models as I understand them to be. This  will be followed by discussion of what I regard as significant aspects of the neuroscience model.


The diagram below shows the differences between the two models as I understand them.



EXPLANATION OF  WHY PSYCHO-ACTIVE DRUG PLANTS IMMEDIATELY  REWARD  USERS No explanation Drug plants contain chemical analogues of brain neurotransmitters; drugs can replace the latter, and  act on reward strata in human (+ animal)  brains.
INHERENT PATTERN OF DRUG USE  Moderate drug use until and unless addiction develops  Being biological in origin, initial drug use is reinforced, leading to  unrestrained drug use, in absence of existing or imposed restraints 
ROLE OF SOCIO-CULTURAL FACTORS INCL. LEGAL, ECONOMIC + PERSONAL  Adverse socio-cultural factors incl. individual psycho- pathologies lead to 

Excessive Drug  Use/Abuse


Positive socio-cultural factors +  accurate drug information alter   unrestrained drug use toModerate Drug Use 

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Such observations suggest that pre-existing psychopathology is not a requisite for initial or even continued drug taking’and that drugs themselves are powerful reinforcers, even in the absence of physical dependence (Gilman et al. 1985:534).

Please note: the above quote was in my previous post. It is repeated here because it should have been followed by the following paragraph:

The ‘reinforcing capacity of a drug’ became the term referring to a particular drug’s inherent capacity to induce animals to repeat actions which result in drug administration. The reinforcing factor appeared to differ for each drug. For example, under a that particular laboratory set-up, rats would press a bar 250 times to obtain caffeine, 4,000 times for heroin, but 10,000 consecutive times to obtain cocaine (Spotts and Shontz 1980:15).

Although wild animals do not have comparable access to drugs, there are numerous examples of them ingesting psychoactive substances. There is a close association between reindeer and the psychoactive fly agric mushroom in Siberia (Furst 1976:101). It is commonly accepted that grazing animals prefer fermented fallen fruit and that birds sometimes select nectars which intoxicate. Altogether, by the 1980s, increasing evidence demonstrated that animals seek out psychoactive experiences. Researchers from the University of California claim knowledge of more than 2,000 cases of animals consuming psychoactive substances, of which 310 were investigated and their use found to be ‘intentional and addictive’ (Greenberg 1983:300). And see next post.

About the same time as queries began about excessive drug seeking, a rush of interest grew in the unfolding science of neurobiology. Instead of electricity firing the brain as formerly thought, scientists discovered that central nervous system activity depended upon at least fifty chemical compounds academics named ‘neurotransmitters’. The latter controlled and coordinated flows of information between the neurons within the brain, including data about emotions, memories and pleasures.

The main chemical transmitters include dopamine, acetylcholine, nor epinephrine, serotonin, gamma amino butyric acid, and the recently discovered opioid peptides. Each possesses a specific molecular and spatial arrangement which enables it to ‘plug’ into a receptor in a target neuron, rather like a key into a lock. The neuron is thus activated: information passes from one neuron to the next, and the neurotransmitter, its function accomplished, decays.

This may seem far distant from packing a cone or sipping gin and tonic. Here is the connection. Human and non- human mammals are not the only natural phenomena containing neurotransmitters. Some plants contain (almost) identical chemicals. A unique situation results. The nicotine in tobacco, for example, fits receptors designed for the acetylcholine receptor and, once plugged into the receptor, nicotine activates the same processes that acetylcholine can activate. Similarly, morphine from opium poppies fits receptors for the body’s endogenous opiates… and so on for each of those plants which contain chemical compounds which are analogous to brain neurotransmitters.

Olds, acknowledged now as one of the fathers of neuroscience, raised the suggestion that mammal brains (that is, those of human plus non-human mammals) might possess a ‘reward’ strata; Olds had in mind some sort of pay-off which would automatically follow mating, eating, and drinking, and thus encourage repetition of these acts. The concept of a reward structure gradually found acceptance, and in 1976 Olds suggested that drug use may also involve the neural substrate concerned with the brain reward system. Olds based this on the structural resemblances between psychoactive drugs and neurotransmitters, and the fact that drug use clearly reinforced further drug use.

Subsequent studies justify Old’s hypothesis and revealed that people consuming drugs are strengthening or inhibiting neurotransmitters in their brains, or changing their synthesis, storage or release. Through this, drug consumers alter emotions, mood, memory, reasoning powers and perceptions of self and others (Levine 1978:344; Nahas 1981).

However, some differences exist between the two situations: ie in the behaviour of brain transmitters versus drugs analogous to natural brain transmitters. Appetite, satiation, sexual depletion and other biological restraints govern mammal capacity to eat drink, and mate. Consequently the latter activities are not constantly reinforced to the extent that drug use is. See below. Additionally, the plant chemicals drug users select are much more resistant to decay than are the mammal neurotransmitters of which the plant chemical are analogues. Consequently plant chemicals remain longer at the site than the genuine neurotransmitters, and often become potent neurotoxic agents (Kosterlitz and Hughes 1978:412).


The results of animal research has received extensive critical scrutiny. It has to do with money. New synthetic drugs are more likely to receive approval from the United States Food and Drug Administration if they have little or no reinforcing capacity. To evaluate this, three research methods are utilized: drug substitution procedures; continuous self administration with naive animals; and use of escape/avoidance behavioral baselines (Thompson and Young 1978:119 129). Tests use a variety of species (e.g. rat, dog, cat, and non human primates); and investigators use different devices (e.g. lever press, panel press), and different routes of drug administration (e.g. intravenous, oral, intragastric, and inhalation) (Kalant et al.1978:466). Research indicates a number of factors exist which can modify individual animal response. However test results for particular drugs are consistent from laboratory to laboratory even with different experimental parameters and test situations.

Neither is the applicability of the findings to human beings in doubt. The Committee on Problems of Drug Dependence of the National Research Council National Academy of Sciences has addressed this matter as have Thompson and Young (1978), and Johanson and Balster (1978). These sources conclude that the model is valid in respect to humans since the results with a particular drug are consistent from laboratory to laboratory. And these results accord with empirical observation: laboratory animals largely self administer the same drugs which are abused by humans, but do not self administer drugs which are not abused by humans. Hallucinogens seem to be an exception; laboratory animals do not self administer these, even though humans do. However, as noted earlier, there are records of wild animals seeking out hallucinogenic plants so the problem here may be one of failure to deliver the drug to the appropriate tissue.

The conclusion therefore, is that drug users everywhere experience changes in the functioning of reward processes in the limbic system of the brain. As a result, in a situation free of effective controls, users in any society with open access to drugs will consume them in an open ended, unscheduled fashion, and without reference to controls which operate with foods, that is, appetite and satiation.

This does not imply that the effects of drugs on reward centres always ‘induce a compulsive drug oriented behaviour’ (Nahas 1981:1). It is the chemical interaction between drugs and neurotransmitters which is similar in both human and non human animals, not the subsequent behaviour.

Human behaviour depends upon values: social, economic, legal and religious. In fact, the late Schuster, one of the seminal figures in research into drug seeking behaviour among animals, clearly appreciated the sociological implications of his work, particularly the increased importance it gives to social controls.

We are depending on a variety of countervailing influences to prevent the organism [Homo sapiens] from engaging in behavior which evolutionary mechanisms have made extremely seductive…. Why is it that members of this symposia audience, most of whom have access to the major drugs of abuse do not use them in an unregulated manner? We know far too little about the social and psychological factors which produce this resistance to the abuse of drugs. It is our position that this is a major area which must be researched if we are to develop effective prevention to unregulated drug use. In conclusion, our major message is that drug taking is biologically normal and society must learn to live with that fact and to develop the necessary constraints to prevent unregulated drug use (Schuster, Renault and Blaine 1979:17) (italics added).


The Committee on Problems of Drug Dependence of the National Research Council National Academy of Sciences
Furst, P. (1972). Flesh of the gods:the ritual use of hallucinogens. London:George Allen & Unwin.

(1979). Hallucinogens and culture.San Francisco: Chandler & Sharp.

Gilman, A.G., L.S. Goodman, T.W. Rall, and F. Murad (eds.) (1985). Goodman and Gilman’s pharmacological basis of therapuetics. 7th ed. New York: Macmillan.

Greenberg, J. (1983). Natural habits in natural habitats. Science News 124: 300-301.
Johanson, C., and R. Balster. (1978). A summary of the results of a drug self-administered study using substitution procedures in rhesus monkeys. Bulletin on Narcotics 30: 627-628.

Kalant, H. et al. (1978). Behavioral aspects of addition: group report. In J. Fleishman (ed.) The bases of addiction: Report of the Dahlem Workshop on the Bases of Addiction. Abakon: Verlagsgesellscgaft.
Kosterlitz, H.W. & J. Hughes. (1978). Endogenous opoid peptides. In J. Fleishman (ed.) The bases of addiction: Report of the Dahlem Workshop on the Bases of Addiction. Abakon: Verlagsgesellscgaft.

Levine, R.R. (1978). Pharmacology: Drug actions and reactions. Boston: Little Brown and Company.

Nahas, G.G. (1981). A pharmacological classification of drugs  of abuse. Bulletin on Narcotics 33: 1-19.

Schuster, C.R., P.F. Renault, and J. Blaine. (1979). An analysis of the relationship of psychopathology to non-medical drug use. In R. Pickens and L. Heston (eds.) Psychiatric factors in drug abuse. New York: Grune & Stratton.

Spotts, J. & F. Shontz. (1980). Cocaine users : a representative approach. New York: Macmillan Publishing Company.

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