News Round-Up: March 2010 1st Edition

Some people with epilepsy may develop psychosis between seizures – interictal psychosis and the prevalence varies between 0 and 16% (Trimble, 1991)(Umbricht et al, 1995). In a Japanese study published in the British Journal of Psychiatry 285 people who had developed both epilepsy and interictal psychosis were assessed (Adachi et al, 2010). The researchers found that the time interval between onset of epilepsy and interictal psychosis displayed a skewed distribution (to the left i.e closer to the onset of epilepsy). The researchers were also able to better characterise the relationship between interictal psychosis and epilepsy in their sample. Thus a family history of psychosis was associated with earlier onset of interictal psychosis as were the generalised forms of epilepsy. The researchers conclude that there were independent risk factors for both epilepsy and interictal psychosis as well as possible shared risk factors.

Dimebon has been a candidate treatment for Alzheimer’s Disease after an initially promising trial reported in the Lancet (see here for further details) and is used in Russia as an antihistamine. However the results of two Phase 3 trials have been recently reported. In the CONNECT study – a double-blind, placebo-controlled trial (n=558), Dimebon did not meet statistically significant improvements on the primary or secondary points relative to placebo. There is still another trial in Huntington’s Disease underway and the company have further information on Dimebon here.

There is a report here on a recent study in Biological Psychiatry (see here) showing evidence of decreased time to remission of depression in a trial of Scopolamine compared to other classes of antidepressants. Scopolamine is a muscarinic antagonist and the tricyclic antidepressants also act on these receptors in contrast with the SSRI’s. There were 23 subjects in this double-blind placebo-controlled cross-over trial and there was both a statistically significant improvement (p=0.001) and clinically significant improvement (32% reduction in MADRS scores compared to 6% in the placebo in the first phase of the study.

There was a recent study (also covered here) in rats which found that suppression of Vasopressin secretion interfered with the ability of adult rats to recognise baby rats.

This adds to other research from the same research group which suggests that Vasopressin may be involved in the formation of emotional memories which are important for social interactions. If this is replicated in humans then it would have application in social cognition which in turn is relevant to a number of conditions.

In another widely reported study, a team have collected intestinal bacteria from a sample of 124 European subjects and sequenced the genomes of the 160 bacteria identified. The resulting genomes when combined into a ‘metagenome’ are larger than the human genome and the significance of this for human illnesses will surely become clearer with time.

There’s a write-up here of another study looking at sleep in African and Hispanic Americans (n=1107) and finding an association between sleeping either less than six hours or more than 8 hours a day and the accumulation of visceral fat. The study was published in the journal Sleep (see here) and was a longitudinal cohort study with various measurements at 5-year intervals. These findings are potentially important in view of other research showing increased mortality in groups with this amount of daily sleep compared to those who sleep between 6 and 8 hours daily. This new research is examining the pathways involved and in turn this information can be potentially useful in stratifying risk although this would require further research.

Psychiatry 2.0

Mind Hacks has two interesting articles. The first is the weekly spike activity in which he links to coverage of a recent neuroimaging study identifying an association between activity in the ventral striatum and perception of inequality. There is also a link to the research blogging awards and an article on the Vul paper on fMRI (see here for further details on the original paper) is in contention for an award. The second article is a look at a recent study published by Craig Bennett and looking at the test-retest reliability of fMRI studies. Bennett produced the tongue-in-cheek paper in which he ‘found’ activity in the brain of a dead salmon and used this to emphasise the importance of correct methodology (see here for further details). The current paper is useful for the appraisal of fMRI papers by the interested reader.

Dr Shock is ever generous with his tips and in this article talks the reader through ‘read it later’, a browser plug-in that’s particularly useful for bloggers. The Differential Biology Reader discusses crowdflower, a piece of software for organising research.  Dr D has an interesting article on transitional objects. The CogSciLibrarian has a piece on Facebook and the ‘Theory of Mind’ while Dr Deb looks at Japanese mobile software that analyses the power spectrum of infant’s cries and suggests why they might be crying. At PsychCentral, Dr Tomasolu has a piece on positive psychology and how to achieve a balance between negative and positive thoughts. Dr Brandemihl has a short piece on Transcranial Magnetic Stimulation in the treatment of depression anticipating an article that is due to be published in the Archives of General Psychiatry.  Corpus Callosum takes a look at 2 American Journal of Psychiatry articles on the relationship between diet and mental illnesses.

Evolutionary Psychiatry

There is an interesting write-up on a recent hypothesis by Professor Wheeler that cooking food may have led to an increase in brain size. The essence of the argument is that cooking reduces the amount of energy needed to digest food. In moving from Austrolopithecus to Homo Erectus and Homo Habilis there was a reduction in the size of the intestines and an increase in brain volume.

The argument is that these anatomical changes were causally related to corresponding behavioural changes which enabled a significantly higher proportion of the body’s resources (i.e energy) to be allocated to the brain. Indeed this has been the subject of a Horizon programme which is available for a limited time here. There’s another interesting write-up, this time of a conference examining the ‘Origins of Human Uniqueness and Behavioural Modernity’. Discussion took place around a number of subjects including the possible role of gifts and adornements particularly in the role of signalling social status.

References

Adachi N et al. Epileptic, organic and genetic vulnerabilities for timing of the development of interictal psychosis. The British Journal of Psychiatry. Vol 196. p212-216. 2010.

Trimble MR. The Psychosis of Epilepsy. New York: Raven Press, 1991.

Umbricht D, Degreef G, Barr WB, et al. Postictal and chronic psychoses in patients with temporal lobe epilepsy. Am J Psychiatry 1995;152:224–231.

Index

You can find an index of the site here. The page contains links to all of the articles in the blog in chronological order.

Twitter

You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link

Podcast

You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast).

TAWOP Channel

You can follow the TAWOP Channel on YouTube by clicking on this link

Responses

If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk

Disclaimer

The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.