Daily Archives: January 1, 2009

Book Review: Descartes’ Error. Emotion, Reason and the Human Brain

The featured book is ‘Descartes’ Error’ by Antonio Damasio.

I thought the book could be divided neatly into two parts.

In the first part Damasio builds up to his Somatic Marker Hypothesis. This is a particularly bold, brilliant and elegant hypothesis which is slowly but surely building up a strong evidence base to support it. Damasio begins with a number of case studies including the classic case of Phineas Gage. Through these cases, Damasio builds an argument for what needs to be explained. In particular he wants to explain how emotions are integral to our ability to make good decisions and cites a relevant case which necessitates Damasio to go beyond the conventional neuropsychological tests in order to confirm practical observations. This in itself shows a great scientific mind in action – wanting to answer a question which is leaping out from observations.

In the second part which is much briefer ‘The Body Minded Brain’, Damasio considers the Mind-Brain issue and I think particularly is included to justify the provocative title of the book and to show how his hypothesis can be used in an age old debate. This debate is also considered by McLaren in his biocognitive model covered in an earlier review.

This was described by the Times Literary Supplement as ‘A Tour De Force of Sheer Reflective Imagination’ which appears on the cover of the book. This is interesting as there may be parallels with the term ‘regulative fiction’ which was used to describe some of the groundbreaking work of Donald Winnicott (discussed further here). This is a really nice book which shows the ways in which bold advances in science can be made with a combination of imagination, reflection, observation, testing and communication.

References

Antonio Damasio. Descartes’ Error. Emotion, Reason and the Human Brain. Vintage Books. 2006. (First Published 1994).

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.

17 Research Studies from 2008

Here are 17 research studies from 2008 that I found interesting.

(1) Happiness in Social Networks

In the BMJ, a study involving three generations of subjects in the Framingham Heart Study, looked at social networks using detailed information on the subjects. The researchers showed evidence that happiness in a person is associated with happiness in members of their social network particularly if they live nearby.

(2-3) Deep Brain Stimulation and Treatment-Resistant Depression

A preliminary study of Deep Brain Stimulation of the Subcallosal Cingulate Gyrus has shown benefit in treatment resistant depression with a 35% remission over 6 months although double-blind studies are required before firmer conclusions can be drawn. A multi-centre study showing deep brain stimulation of Brodmann Area 57 as a viable approach for treatment-resistant depression was presented at the American Psychiatric Association Meeting. The link here is secondary source material. However this is another study supporting the efficacy of Deep Brain Stimulation in Treatment-Resistant Depression. If further studies support these findings then DBS would offer a useful additional approach to treatment-resistant depression.

(4) Predicting Depression

In the PredictD study, King and colleagues used a model predicting risk of depression in people attending a general practice that had been developed in Europe and used this in a population in Chile. The model incorporates 10 factors including age, sex, Short Form 12 mental health subscores and highest level of  education. Effective predictive models can be quite useful in screening programs provided they are practical.

(5) Rember in Alzheimer’s Disease

One of the big studies of 2008 was a trial involving a drug called Rember in people with Alzheimer’s Disease presented at the International Conference on Alzheimer Disease in Chicago. What is remarkable is that Rember is a special preparation of a substance known as methylene blue which was first created in the 1890’s. Methylene blue is commonly used in laboratories and was used to treat malaria but has some unusual side effects e.g. turning the sclera blue. What is also remarkable was that in the study, Rember reduced the cognitive decline by 81% over 19 months in 321 patients.

(6) Anti-TNF and Verbal Fluency in Alzheimer’s Disease

A recent study published in BMC Neurology has shown that administration of an anti-TNF drug leads to a rapid improvement in verbal skills in people with Alzheimer’s Disease. The drawbacks however are that this is a small (n=12) open-label trial and so further research is needed to expand upon these findings. However this drug acts differently to current medication for Alzheimer’s Disease.

(7) Predicting conversion from Mild Cognitive Impairment to Dementia

A five factor model for predicting conversion from MCI to dementia was found to have 81% sensitivity and included immediate recall, functional assessment, smell test, MRI Hippocampal volume and Entorhinal Cortex volume. Predicting conversion may be of benefit in starting appropriate treatments early although there is a long way to go and plenty of research before any such conclusions can be safely drawn.

(8 ) ACE-inhibitors in Hypertension and Dementia

The authors of a study which involved 1.7 million people, found that those people taking ACE inhibitors for hypertension were 40% less likely to get dementia and 45% less likely to develop other serious consequences of dementia than people using other medication for hypertension. The research was presented at a conference in Chicago by a research group from the Boston University School of medicine. This is secondary source material and so I am waiting to see the published study.

(9) Russian Antihistamine for Alzheimer’s Disease

Another big study was the trial of Dimebon for Alzheimer’s Disease in a study in Russia. There was actually found to be an improvement in cognition over the study period and the next stage will be looking to see if this drug gets regulatory approval.

(10) A Large Scale Study of Prevalence of Mental Illness in People with Learning Disability

A Western Australian study using a database registry of 245,749 people with mental illness and Learning Disability found that 31.7% of people with Learning Disability had a concurrent mental illness. This is a study with a large sample providing evidence of comorbidity in people with Learning Disability.

(11) The Genetics of Personality Disorder

A study of 1386 Norwegian twins found 38% heritability for Antisocial Personality Disorder, 35% heritability for Borderline Personality Disorder, 31% for Histrionic Personality Disorder and 24% for Narcissistic Personality Disorder. Antisocial Personality Disorder and Borderline Personality Disorder were found to be more closely related than the other disorders. This is a large study which provides evidence which can be used for instance in theoretical models of personality disorder.

(12-14) Genetics and Schizophrenia

Three large genetics studies looking at a combined total of over 40,000 people have implicated chromosomes 1, 12, 13, 15, 16 and 22 in schizophrenia. The relationship between genes and schizophrenia is however unlikely to be straightforward. The environment impacts on the way genes are expressed as proteins and it is this intersection which must be examined to make sense of the findings of any genes that are implicated. Additionally localising to the chromosomal level sets the scene for further studies to identify the genes within that part of the chromosome that are involved.

(15) Cultural Differences in Religious Delusions

A study suggests that religious delusions in schizophrenia are a cultural phenomenon. The researchers looked at the frequency of religious delusions in people with schizophrenia in the former East and West Germany before German reunification.

(16) The Genetics of Bardet-Biedl Syndrome

A remarkable story of cross-disciplinary collaboration has shown a possible pathway from genes to schizophrenia. Essentially the disease linking three different genes together was Bardet-Biedl Syndrome which affects the eyes, kidneys as well as behaviour. The three genes were BBS4, PCM1 and DISC1 which have been shown to act in concert during neural development. Confirmatory research has been conducted in families with schizophrenia but there will undoubtedly be many more pieces of the jigsaw to fit together.

(17) Inflammation and Sleep

Researchers using an inflammatory marker – nuclear factor kB – have shown an increase in people following partial sleep deprivation. Linking sleep deprivation with inflammation would have many important implications and so it will be interesting to keep an eye on research in this area.

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.