Month: January 2008

Would you vaccinate your child against cocaine?

Treatment Online has an interesting piece on the development of a cocaine vaccine. Unlike other drugs that reduce the pleasurable effect of addictive drugs, this is genuinely a vaccine – it persuades the immune system to attack cocaine molecules.

There are various drugs that are sometimes described conveniently, but inaccurately, as ‘vaccines’ for addictive substances.

For example, disufiram (aka Antabuse) creates a severe hangover 10 minutes after taking any alcoholic drink by inhibiting certain enzymes in the liver which break down alcohol. The idea is that it acts as an instant form of aversion therapy.

A drug called naltrexone blocks opioids in the brain which all pleasurable drugs trigger, either directly (in the case of heroin), or indirectly (in the case of alcohol). Naltrexone simply aims to reduce how ‘fun’ the drug is, leading to extinction of the link between the drug and the ‘high’.

However, neither of these are actually ‘vaccines‘ in the proper sense of the word.

Vaccines are substances that stimulate the immune system. The immune system identifies and adapts to the key features of the potentially dangerous invader, and works to destroy it.

Of course, this happens when foreign pathogens (like diseases) enter the body, but the immune system can be triggered by safe or less dangerous substances that share the ‘key features’ with the more dangerous disease. This safe or less dangerous substance is the vaccine.

Edward Jenner invented the procedure after working out that giving people a tiny amount of the non-lethal cowpox virus vaccinated them against the deadly smallpox virus. In fact, this is where the word ‘vaccinate’ comes from as ‘vacca’ means cow in Latin.

The developers of the new cocaine vaccine, known as ‘TA-CD’, are doing essentially the same thing by cleverly combining a deactivated cocaine molecule with a deactivated cholera toxin molecule.

The deactivated cholera toxin is enough to trigger the immune system, which finds and adapts to the new invader.

Because the cholera toxin and the cocaine molecule are combined, the immune system also adapts to the key features of cocaine, so works out how to seek and destroy cocaine molecules.

This means they never reach the brain in sufficient quantities to cause an effect.

A key advantage is that unlike other anti-addiction drugs, which have to be in the body to have their effect, the cocaine vaccine permanently changes the immune system to neutralise cocaine.

Of course, it may not be completely effective, or it may not work in all people, but that’s the aim.

The drug is about to studied with a Phase III clinical trial to see if it useful in treating cocaine addiction, after which, if it is shown to be safe and effective, it could be approved for widespread use.

Unlike the current concerns about the supposed ‘new ethical challenges’ of medical therapies being used by healthy people (which, as we’ve noted, are actually as old as drugs themselves), this therapy may present a relatively new ethical dilemma.

If effective, you can see that some parents might want to vaccinate their non-addicted, perfectly healthy children, so they are ‘immune’ to cocaine.

The difference here, is that once given, the ‘immunity’ may be permanent. In other words, you would make the decision that your child will never be able to experience the effects of cocaine for the rest of their life.

One interesting effect might be an ‘arms race’ between illicit drug producers and vaccine makers. As children become ‘vaccinated’ against the common drugs of abuse, the market for street drugs would fragment and diversify into drugs that don’t have vaccines yet.

A Brave New World indeed.

Link to Treatment Online on cocaine vaccine.
Link to PubMed papers on cocaine vaccine.
Link to Toronto Globe and Mail article on the vaccine.

Are repressed memories a product of culture?

Harvard Magazine has an interesting article on whether it is possible to repress memories to force them into the unconscious.

As well as discussing the phenomenon, it also updates us on the challenge put forward by the McLean Hospital Psychiatry Lab: find a single account of repressed memory, fictional or not, before the year 1800 and win $1000.

It turns out, the $1000 dollars has just been awarded, although the account only sneaked past the post – it was from 1786.

The point of the challenge was because the McLean lab suspect that repressed memories, also called ‘dissociative amnesia’, are a ‘culture bound syndrome‘ – in other words, they’re so heavily influenced by cultural ideas that they are not a universal feature of the human mind and brain.

If they are a universal human feature you’d expect them to be reported throughout history, but it turns out that there are no clear reports of anyone repressing a memory, either in historical writing or in fiction, until the late 1700s.

Their paper [pdf] on culture, dissociative amnesia and their challenge, was published just before they awarded the prize, so doesn’t include the winning account, but discusses the cultural influences on this controversial concept.

As well as being enormously good fun, their challenge is an interesting way of gathering date to inform a hot topic in psychology.

Link to Harvard Magazine article on repressed memory and culture.
pdf of paper ‘Is dissociative amnesia a culture-bound syndrome?’.
Link to McClean Psychiatry Lab challenge page with entries.

Changing minds

Online chin-scratching club Edge have asked their annual question. This year’s it’s “What have you changed your mind about?” and the respondents include a number of cognitive scientists or people thinking about mind and brain issues.

Actually, all of them are a good read (although spot the few who don’t seem to have changed their mind very much!).

We’ve listed the psychology and neuroscience-related answers below if you want to cut to the chase (and fixed a few broken links from the original website along the way).

Enjoy!

Continue reading “Changing minds”

Challenging the banality of evil

The British Psychological Society’s magazine The Psychologist has just been redesigned and relaunched and its cover article on the psychology of evil has been made freely available online.

The phrase the ‘banality of evil’ was coined by philosopher Hannah Arendt after witnessing the trial of high-ranking Nazi Adolf Eichmann who seemed, at least to Arendt, to be the most mundane of individuals whose evil acts were driven by the requirements of the state and orders from above.

A number of social psychologists, most notably Philip Zimbardo – famous for his prison experiment, have argued for a similar view of evil, suggesting that evil occurs when ordinary individuals are put into corrupt situations that encourage their conformity.

The cover article in The Psychologist re-examines key historical studies and new experimental evidence to challenge the “clear consensus amongst social psychologists, historians and philosophers that everyone succumbs to the power of the group and hence no one can resist evil once in its midst”.

For example, some Nazis who later claimed to be ‘just following orders’ often exceeded their orders in their brutality, while others deliberately avoided capricious violence, suggesting a significant amount of personal choice was involved.

Interestingly, this seems to apply equally to Eichmann and Arendt’s famous phrase may have been a result of her leaving the trial at a crucial point:

On the historical side, a number of new studies ‚Äì notably David Cesarani’s (2004) meticulous examination of Eichmann‚Äôs life and crimes ‚Äì have suggested that Arendt‚Äôs analysis was, at best, naive. Not least, this was because she only attended the start of his trial. In this, Eichmann worked hard to undermine the charge that he was a dangerous fanatic by presenting himself as an inoffensive pen-pusher. Arendt then left.

Had she stayed, though, she (and we) would have discovered a very different Eichmann: a man who identified strongly with anti-semitism and Nazi ideology; a man who did not simply follow orders but who pioneered creative new policies; a man who was well aware of what he was doing and was proud of his murderous ‘achievements’.

The article also looks at famous psychology studies, such as the Stanford Prison Experiment and Milgram’s conformity studies, and argues that the people who were supposedly most likely to be led into brutality were actually psychologically quite different from the others, suggesting that they were not just ‘average people’.

It’s a refreshingly provocative look at the widely accepted idea that group pressure is the key driving force in the birth of ‘evil’.

Link to article ‘Questioning the banality of evil’ (with link to PDF version).

Full Disclosure: I’m an unpaid associate editor of The Psychologist.

Sampling risk and judging personal danger

We live in a dangerous world and we’ve learnt to judge risk as a way of avoiding loss or injury. How we make this appraisal is crucial to our survival and an innovative study published in December’s Risk and Analysis investigated what influences risk perception in everyday life and has shown that our retrospective estimations of risk are quite different from how we judge them at the time.

Many studies on the psychology of risk ask people to look back on past situations or judge risk for hypothetical or lab-based situations.

The trouble is, imaginary or lab-based situations may not be a good match to real-life (after all, what’s really the danger?) and our perceptions when looking back might be influenced by the outcome – perhaps we judge things as less risky if they turned out OK in the end.

One way of trying to get a handle on how people feel during the flow of everyday life is to use a method call ‘experience sampling’.

This usually involves giving participants a pager, an electronic diary or just sending them texts to their mobile phone.

Participants are alerted at random times during the day by whatever method is chosen and they’re asked to rate how they feel there and then, or as soon as safely possible (I discussed how this has been applied to psychotic experiences in a BPSRD article in 2006).

In this study, participants were asked to rate their mood, what activity they were doing, what is the worst consequence that could occur, how severe that consequence could be, how likely it is to happen and what would the risk be to their well-being.

Generally, risks were perceived to be short term in nature and involved “loss of time or materials” related to work and “physical damage”.

Interestingly, everyone rated the severity of risk as about the same, but women were more likely to think that the worst consequence was likely to occur.

Furthermore, the better the mood of the participants (both male and female), the less risky they thought their activity was.

As an additional part of the study, participants were asked to look back and re-assess some of the situations they rated on the spot. These ratings tended to be much lower, showing that people tend to judge things to be more risky ‘in the heat of the moment’.

Both of these findings demonstrate the importance of emotion in risk judgements, suggesting that it forms another source of information, along with more calculated rational estimates.

In fact, this is one of the key ideas behind understanding anxiety disorders.

Anxiety acts as an emotional risk warning, but it can get massively ‘out of synch’ with our rational judgements, so even when we ‘know’ that (for example) the risk of air travel is smaller than the risk of driving a car, ‘in the heat of the moment’, the information from our emotions overrides this in our judgement of risk in the form of anxiety.

Of course, risk perception in itself is an important topic to understand, particularly as risk judgements are the basis of safety decisions in many professions.

Link to PubMed abstract of paper.
pdf of full-text of paper.