Troublemaker’s Fringe, tomorrow, after the day job

If you’re in London Town Wednesday evening, don’t forget to come along to the Troublemaker’s Fringe, where we’ll be tackling the problems of science journalism and discussing how misleading, dangerous and inaccurate stories keep making the headlines.

Hilariously, we’ve already been slagged off by Steve Connor of The Independent who deals out some scorching criticism, calls us arrogant, and defends the accuracy of the mainstream media by saying:

The medics met in a pub in London last night to explain why the “mainstream media’s science coverage is broken, misleading, dangerous, lazy, venal and silly”.

Except we’re meeting tomorrow night, and there’s only one medic.

Ugh! Feel the heat!

Link to full details of the Troublemaker’s Fringe.
Link to Steve Connor in The Independent (I recommend the comments).

A neurobiology of the disordered mind

Newsweek has a short but smart essay by neuroscientist Eric Kandel who riffs on some of the latest developments that have pushed forward our understanding of the neurobiology of mental disorder.

Kandel gives a description of one of the big biological discoveries from recent years, namely copy number variations, and explores what they might tell us about the development of psychiatric disorders:

One major advance has been the discovery that there is much more variability in the genome than had been anticipated, and that this takes the form of copy number variation (CNV). These are duplications or deletions of segments of a chromosome, often involving several or tens of genes, that enhance or depress the actions of specific genes. A well-known example of a CNV is the extra copy of chromosome 21 resulting in Down syndrome. It has recently been discovered that this type of variation is extremely common in everyone’s genome.

As he goes on to explain, CNVs have caused a lot of excitement in the world of mental illness research, not least because they’ve been found to occur in ‘out of the blue’ cases of schizophrenia – people without a family history of the disorder – suggesting that the disorder could be partially explained in some people by DNA ‘lesions’.

Some rare CNVs have been found to greatly increase the risk for schizophrenia, but unfortunately they don’t help explain the genetics of schizophrenia in general because there are many people with schizophrenia who don’t have these rare CNVs.

Nevertheless, this rare CNV finding may help us understand the neurobiology of the disorder by giving us clues based on how these unusual copy variations affect brain growth and protein expression.

Interestingly, those CNVs which have been found to increase the risk of schizophrenia also increase the risk for other disorders such as autism and intellectual disability (what the Americans call ‘mental retardation’) – suggesting that our diagnostic divisions between disorders may not be well supported by genetics.

Despite the title of the article, Kandel also highlights recent developments in psychotherapy, which have given us far the biggest advance in effective treatments for mental disorders in recent years.

Newsweek seem to have just released a whole collection of articles on biomedical sciences of which Kandel’s contribution is a part. But don’t miss a good article on ‘how science will enhance your brain’ and another piece on epigenetics.

Look on the right hand side for links to all the articles in the series.

Link to Newsweek on ‘A Biology of Mental Disorder’.
Link to Newsweek on ‘How Science Will Enhance Your Brain’.
Link to Newsweek piece on epigenetics.

DSM-V bun fight in full swing

The arguments over the forthcoming revision of the psychiatrists’ diagnostic manual, the DSM-V, have just been heated up again by an unusually acerbic response from the American Psychiatric Association attacking their main critic.

The article that condemns the new diagnostic manual committee by ex-DSM chairman Allen Francis’ has just been officially published, alongside an interview where he furthers his damning criticism.

The American Psychiatric Association has apparently written a response which seems to have been leaked online, and it contains some robust responses to Francis’ points as well as a surprising ad hominem attack – suggesting he is motivated by losing money after the DSM-IV goes out of print.

The APA makes some good replies to the main criticisms, defending their record of openness, their reliance on the scientific data and their proposed changes to the diagnostic process based on current best practice, but the final paragraph is quite suprising:

Both Dr. Frances and Dr. Spitzer have more than a personal ‘pride of authorship’ interest in preserving the DSM-IV and its related case book and study products. Both continue to receive royalties on DSM-IV associated products. The fact that Dr. Frances was informed at the APA Annual Meeting last month that subsequent editions of his DSM-IV associated products would cease when the new edition is finalized, should be considered when evaluating his critique and its timing.

This line of criticism is perhaps most surprising for the fact that, as recently reported in USA Today, 68% of the DSM-V committee report financial ties with drug companies.

While the committee rules require that members cannot receive more than $10,000 in drug company payments while at work on the DSM, I can’t help but thinking that they are better off not opening the Pandora’s box of conflict-of-interest criticisms.

Link to Frances article in Psychiatric Times.
Link to Frances interview in Psychiatric Times.
Link to leaked alleged APA response (via Carlat blog).

Honey, I’m shrinking the kids

I’ve just discovered a New York Times article from earlier this year about psychologists who are studying their own kids in the service of top flight scientific research.

Studying one’s own kids has a long and proud tradition in psychology. Perhaps the first person to do so formally was Charles Darwin, who in 1877 published his paper A Biographical Sketch of an Infant which was based on observations of his own children.

Freud, of course, studied and analysed his own children (most famously Anna Freud) but perhaps the most influential was child psychologist Jean Piaget who based many of his ideas on observations of his own three children.

Also notable was one of the first women ever to be awarded a PhD in psychology, Milicent Washburn Shinn, who did her research on her own niece.

The New York Times piece covers many modern cognitive science projects that are based on observations of the researchers’ children to get the sort of in-depth data it would otherwise be impossible to obtain.

The ‘human speechome’ project is probably the most well-known where developmental psychologist Deb Roy is recording virtually every sound made by his young child from birth to “observe and computationally model the longitudinal language development of a single child at an unprecedented scale”.

Roy discusses the project and additional audio and video illustrates the article with more detail on the project.

The article also tackles some of the ethical issues of using your own children as research participants. This is an important topic because currently, there are no widely agreed guidelines on this long-established practice.

This exact topic sparked an article in the prestigious Journal of the American Medical Association earlier this year to mull over the rights and wrongs of the situation.

The article covers a wide range of studies although is quite US-centric. One of the most notable examples this side of the pond resulted in a book by UK psychologist Charles Fernyhough released as A Thousand Days of Wonder in the US and The Baby in the Mirror in the UK which describes the development of his daughter through her first three years of life.

Link to NYT ‘Test Subjects Who Call the Scientist Mom or Dad’.
Link to JAMA article on ‘Parent investigators: a dilemma’.
Link to PubMed entry for same.

The effect of the rats on the rat race

Photo by Flickr user B Tal. Click for sourceNot Exactly Rocket Science covers an intriguing study on how people try less hard in a competition as the number of competitors increases.

The researchers started off with a simple observation that US students tended to get better marks when they took their exams in smaller exam rooms.

This could have been for many reasons of course, so they set about running several experiments to see if the effect was genuinely down to competitiveness.

These additional studies found that smaller groups do indeed increase competitiveness, and several also allowed them to attempt to explain why:

…they told 50 students that they would have a week to win $100 by adding as many Facebook friends as possible. They found that the students felt more motivated to compete when facing 10 competitors compared to 10,000, and they were also more likely to compare themselves against the others within the smaller contest. The number of competitors predicted the students’ motivations to compete, but that association disappeared after adjusting for their tendency to compare themselves with others.

This same experiment allowed them to rule out the possibility that the students were more motivated in the smaller group, simply because they thought the task would be easier. They certainly felt that way (albeit wrongly – in both cases, the prizes went to the top 20% and the students understood that) but it didn’t affect their behaviour. Adjusting for this perception of difficulty didn’t strongly affect the link between number of competitors and motivation.

In other words, the effect of the number of competitors on our motivation seems to work through how likely we are to compare ourselves to others.

But contrary to what we might expect, those who compare themselves most to others are more likely to be competitive when there are fewer people.

The authors suggest that this may be because personal comparisons are easier when we can think of our competitors as individuals rather than having a more abstract idea of a nebulous ‘group’.

Anyway, another great piece from Not Exactly Rocket Science, where you can get a more detailed low-down on the study.

Link to NERS on competitors and the motivation to compete.

The straight dopamine theory could be up in smoke

There is now growing evidence that cannabis use causes a small but reliable increase in the chance of developing psychosis. Traditionally, this was explained by the drug increasing dopamine levels in the brain but a new study shortly to be published in NeuroImage suggests that the active ingredient in cannabis doesn’t effect this important neurotransmitter.

Despite some dissenting voices, disruption to the mesolimbic dopamine pathway is widely thought to be the key problem in the development of delusions, hallucinations and the other psychotic symptoms commonly diagnosed as schizophrenia.

This has led to the assumption that the small increased risk of psychosis reliably associated with cannabis use is due to the drug increasing dopamine levels in a deep brain structure called the striatum.

In itself, this is partly based on another assumption – the virtual mantra of recreational drug research that ‘all drugs of abuse increase dopamine levels in the reward system’ of which the striatum is a part.

This new study, led by neuroscientist Paul Stokes, tested dopamine levels by using a type of PET brain scan where participants are injected with a radioactive tracer that binds to free dopamine receptors. Higher dopamine levels will mean that there are less free dopamine receptors and, therefore, lower tracer levels.

Participants were tested twice, once when given placebo and once when given a dose of pure THC – one of the most important active ingredients in cannabis. The dose was designed to be roughly equivalent to the amount you might absorb from a single joint.

The researchers found no difference in dopamine levels between the THC and the sugar pill, even though the participants clearly reported the effects of the drug.

Although they only tested 13 participants, this is the largest study of its kind so far. These type of neurotransmitter tracer studies are know to produce conflicting results at times, so further experiments will be needed to be sure of the result.

But if it is the case that cannabis does not cause a significant increase in dopamine levels, this will mean our ideas about cannabis and psychosis will need a rethink.

It also shakes up the idea common idea that all recreational drugs are pleasurable because they affect the ‘dopamine reward system’.

Link to PubMed entry for the ‘in press’ study.

In our wildest dreams

Photo by Flickr user NebulaskiN. Click for sourceIn the latest of his excellent columns for Scientific American psychologist Jesse Berring reviews the current theories that try and explain why we’ve evolved to have dreams.

One of the most interesting is the ‘Threat Simulation Theory’ which argues dreams are a form of night-time survival training, based on research that found that dreams often put us in scenarios of personal danger:

In a 2006 study published in the journal Consciousness and Cognition, Zadra, Desjardins, and Marcotte performed a content analysis on a set of 212 recurrent dreams reported by participants ranging from 18-81 years of age.

Among their findings, escape and pursuit themes were the most frequent type of threat found in their sample (25.9 percent), followed by accidents and misfortunes (19.7 percent), aggression and violence (19.0 percent), physical difficulties (17.0 percent), emotional difficulties (7.5 percent), and disasters (3.4 percent).

Furthermore, in nearly all cases the dreamer him- or herself (rather than a stranger or loved one) was the specific target of the threat and usually the dreamers actively participated in some way to resolve, escape, or combat the threat.

The article covers a whole stack of alternatives and is written in Berrings’ usual engaging style.

Link to ‘Dreaming of Nonsense: The Evolutionary Enigma of Dream Content’.