Author: vaughanbell

Could a wide-spread brain infection account for differences in cultures across the world? Possibly, is the surprising answer from a new research paper published in the Proceedings of the Royal Society of London.

If cognitive parasitology isn’t your thing (and it may not be, as I just made that up) the research is expertly discussed by Carl Zimmer.

The disease caused by the parasite Toxoplasma gondii is called toxoplasmosis and has been linked to ‘personality’ changes in rats and mice.

Although controversial, some suggest that this infection may also be linked to personality changes in humans, suggesting that different rates of infections in different countries may lead to differences in ‘national character’.

You’re best going to Zimmer’s write-up for a concise take on the major implications, but I’ll leave you with an intriguing point he finishes on:

“[This] raises another interesting question: what about other parasites? Do viruses, intestinal worms, and other pathogens that can linger in the body for decades have their own influence on human personality?”

Link to Zimmer’s article ‘A Nation of Neurotics? Blame the Puppet Masters?’.

OR-Live is a website that carries videos of surgical procedures, including a section where you can watch neurosurgery in action.

A brain clipping and coiling procedure to repair an aneurysm will be broadcast live today, and if that doesn’t take your fancy, there’s plenty more in the archive.

One of my favorites is a temporal lobectomy (removal of part of the temporal lobe) that was completed to remove the source of untreatable epileptic seizures.

It has a winning combination of a fascinating surgical procedure and a slightly uncomfortable professor of neurosurgery looking a bit awkward in front of the camera.

The site is a little confusing in that you need to use the ‘Watch Live Webcast’ link to launch an archive recording as well as see a live broadcast.

Link to neurosurgery at OR-Live (via Neurocontrarian).

There’s a thought-provoking piece in the latest issue of open-access medical journal PLoS Medicine on whether antidepressants ‘correct’ a problem in the brain, or just create an altered state that may be useful for people with low-mood problems.

It is notable that the way psychiatric drugs are described is usually because of marketing. For example, SSRIs are classed as ‘antidepressants’, dopamine agonists and ‘antipsychotics’ and drugs like sodium valproate as ‘mood stabilizers’.

These terms have been promoted by drug companies in an effort to establish a market for particular compounds and imply that they directly affected these conditions. Often, they have been invented to replace previous labels which were no longer useful in marketing the drug.

The authors of the PLoS Medicine paper argue that trials have shown that, for example, opiates and amphetamine-like drugs can have beneficial effects in depressed patients but are not considered ‘antidepressants’.

The paper also tackles the idea that depression is ’caused by low serotonin’ in the brain and that antidepressants ‘correct’ this problem.

The low serotonin theory of depression must rank as one of the most widely known and least supported scientific theories, as there is comparatively little evidence that backs this explanation.

The authors argue that instead of trying to explain the action of a drug in terms of a disease it is meant to ‘correct’, it is more accurate to describe the drug in terms of its general actions in the brain which could be coincidentally useful in treating certain conditions.

I suspect, this is what inevitably happens anyway, owing to the needs of marketing.

Typically, when a drug is discovered, it is targeted at a condition which is likely to be profitable (depression being the classic example). At this point, it is usually marketed as an anti-something-or-other.

Later, when the profits begin to come in, the pharmaceutical company looks to widen the market and tests it on other, less prevalent, but hopefully still profitable conditions (e.g. social phobia).

For example, SSRI drugs (such as Prozac) are now indicated for depression, PTSD, obsessive-compulsive disorder, eating disorders and panic disorder to name but a few.

The marketing then begins to place less emphasis on its original label, so it is seen as more wide acting.

Have a look at the archives of the front page of the Seroquel website before and after it gained approval for the treatment of bipolar disorder and notice how the term ‘antipsychotic’ is suddenly not so prominent.

Perhaps to put the paper in context, psychiatrist Dr Joanna Moncrieff, one of the authors of the PLoS Medicine paper, is co-chair of the Critical Psychiatry Network – a group of psychiatrists who dispute the predominance of biological models of mental disorder and campaign for a less coercive psychiatry.

Link to PLoS Medicine article ‘Do Antidepressants Cure or Create Abnormal Brain States?’