Antidepressant Study Challenges Previous Findings: News Round-Up – March 2012 2nd Edition

There is a meta-analysis in the Archives of General Psychiatry where the authors analyse randomised controlled trials of Venlafaxine and Fluoxetine. This study occurs in the context of a previous study by Kirsch and colleagues who concluded that antidepressants were no more effective than placebo in the treatment of mild depression. However the authors of this paper conclude that the data shows that both antidepressants show an advantage over placebo in cases of mild depression. They responded to many of the criticisms that Kirsh and his team raised as they included unpublished data and it will be interesting to see if there is a response from well known commentators like Dan Carlat and Irving Kirsch himself. In a well publicised study in the New England Journal of Medicine two drugs used to treat Alzhimer’s Disease – Donepezil and Memantine were examined in 295 older adults in the community. All of the people in the study were on Donepezil initially and they were divided into four groups – one group continued Donepezil, one group, discontinued Donepezil, one group discontinued Donepezil and started Memantine and another group continued Donepezil with the addition of Memantine. A Memantine placebo was also included for comparison with Memantine. The researchers used the standardised Mini-Mental State Examination as a measure of treatment outcome, the study continued for 52 weeks and a difference of 1.4 points on the MMSE was used as a clinically significant marker. The main finding was that people treated with Donepezil showed an improvement that exceeded the 1.4 points that the researchers identified as being clinically significant. The researchers concluded that the study supported the use of Donepezil for moderate to severe Alzheimer’s Disease.

An Italian study of the oldest old looking at gene associations found that only the APOE4 allele was associated with dementia in the genes they analysed. The APOE4 gene has been strongly associated with Alzheimer’s Disease and this study suggests that this relationship still holds at an advanced age. Using Magnetoencephalography, researchers investigated subjective memory impairment. They found that people with subjective memory impairment showed a small but significant reduction in a marker of functional connectivity (‘synchronisation likelihood’) between brain regions compared to a control group. These are interesting results although it will be useful to see the results of other studies including prospective cohort studies. In another study, the researchers characterise the pattern of functional connectivity in Alzheimer’s Disease. They found that initially there was a decrease in functional connectivity in the posterior default mode network with an apparently compensatory increase in functional connectivity in the anterior and ventral mode networks followed by a decrease in functional connectivity in all networks. Methylene Blue is a substance which is used to stain cells for histological examination and it is currently being investigated for Alzheimer’s Disease as well as a number of other conditions. The researchers in this in vivo and in vitro study found evidence that Methylene Blue was a potent inducer of autophagy, a mechanism by which cells essentially self-destruct. This is useful when cells are compromised or during development.

Treating disorders of the mind and brain with medication means getting that medication to the brain. The brain has a very effective protective mechanism known as the Blood-Brain Barrier. This barrier prevents many substances from passing through some of which may be toxic to the brain and this is really important particularly when people have other illnesses. Many drugs can pass through the Blood Brain Barrier but there are many therapeutic approaches including gene therapy where this is not the case. In these cases researchers will use lumbar punctures to deliver the therapeutic agents. However compared to taking tablets, lumbar punctures need more resources (see here for further details). An alternative method for getting drugs into the Central Nervous System is the use of focused ultrasound but it should be noted that this is currently being researched before it can be used in routine clinical practice and only if it has proved safe. The use of focused ultrasound to open the blood-brain barrier to facilitate the delivery of drugs to the brain is discussed in this paper.

The Gorilla genome has been fully sequenced and it turns out that in some parts of the genome, the Gorilla is more closely related to us than are Chimpanzees! Are we more similar to Gorillas than Chimpanzees in some ways?

Appendix – Complete Annual News Items from Previous Years

Caution: The combined word count is 86,000 words so it may take some time to read!

News Roundup 2008

News Roundup 2009

News Roundup 2010

News Roundup 2011

An index of the site can be found 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). It is available for a limited period. 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.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s