Friday, March 13, 2009

Doidge (Neuroplasticity) review - part 3 (Schwartz)

Doidge devotes a chapter to discussing obsessive-compulsive disorder. He claims that a treatment developed by Jeffrey M. Schwartz is "plasticity-based". The implication is that other psychological treatments for OCD are NOT "plasticity-based."

Schwartz has published articles in the literature going back into the 1980's looking at OCD patients using PET imaging.

I do not find any good study in the literature about Schwartz's particular technique, as published in his book, in particular no study comparing his technique with CBT.

Also the theory is presented that OCD is caused by a failure for the caudate nucleus in the brain to "shift gears automatically", and that the therapy described is a means of "shifting gears manually." While there are a variety of brain metabolism changes in OCD, I think it is an overly strong statement to believe that this is literally true. One could use the idea of the "caudate gear box" as a metaphor, but it may be quite inaccurate, or at least poorly supported by clear evidence, to be taken literally.

So it concerns me that the chapter in Doidge's book about the "brain lock" approach is more of a book plug than something founded on solid evidence. Doidge could well have made the case that CBT is a type of "neuroplasticity-based treatment". In fact, there is good data to support such a case--including numerous imaging studies--and including a recent paper which Schwartz himself co-authored, which shows various regional changes in brain metabolism associated with improvement in OCD symptoms from intensive CBT:
http://www.ncbi.nlm.nih.gov/pubmed/18180761

Yet, I think it is important to be open about any new therapeutic idea--it may be that the "brain lock" therapy for OCD could be helpful to many people. It's just that Schwartz's book has been given an endorsement by Doidge without a convincing amount of good evidence, while minimizing the robust evidence favouring CBT.

Doidge (Neuroplasticity) review - part 2 (Taub)

Doidge devotes a chapter to the work of Edward Taub. I think Taub's ideas are simple but brilliant. He developed a treatment called "constraint-induced movement therapy" which appears to be remarkably effective to help with recovery from strokes and other injuries.

The simple idea is to restrain the normal limb, almost continuously, for at least weeks at a time, after a neurological injury. Otherwise, the normal limb will compensate for the affected limb. If the normal limb is constrained, the brain itself will develop new pathways to improve the function of the affected limb.

This treatment has good evidence-based support:

http://www.ncbi.nlm.nih.gov/pubmed/18077218

{this 2008 study is from Lancet Neurology, one of the top journals in neurology}

http://www.ncbi.nlm.nih.gov/pubmed/17077374


{another very important study from 2006 in JAMA}

I'm curious about the applications of this sort of therapeutic idea to psychiatry. Psychiatric symptoms can be like other neurological impairments, and the psychoanalytic phenomenon of "defences" may be analogous to the tendency for a neurologically-injured person to favour the non-affected limb, while the affected limb loses more and more function. A psychological therapy which challenges defences may be something like a Taubian "constraint-induced movement therapy" for the mind.

Importantly, in order for Taub's therapy to work, the constraint has to be applied almost continuously during waking hours, for at least weeks at a time. It is an immersive experience. It is an interesting challenge to find more psychological therapies that can be "immersive" in this way.

Doidge (Neuroplasticity) review - part 1 (Merzenich)

This post begins my review of Doidge's references from his book on neuroplasticity.

The first references I have looked through pertain to the work of Michael Merzenich. He has done very interesting research, dating back 4 decades, a lot of it having to do with studying the auditory cortex, and how it changes in response to stimulation of various sorts during different phases of development. Also he done major work researching and developing cochlear implants for treating hearing loss.

His 2006 article about using a "brain plasticity based training program" to improve memory in older adults (http://www.ncbi.nlm.nih.gov/pubmed/16888038) is interesting and encouraging, yet it warrants a close look at the actual results: the memory improvements from this technique were very modest (though significant), also the control groups were both quite passive (one group just looked at DVD videos, the other had no "intervention" at all). It would have been much more interesting to me to see an active control group in which the individuals would be doing simple memory exercises or other active intellectual stimulation for the same length of time. Because this type of active control was absent, the results may aggrandize the specific form of skill training described in the study; this skill training regimen is now being marketed, and money is surely disappearing from the pockets of many people, including many elderly people who may not have an abundant financial reserve. This makes me especially less enthusiastic about the results. I have no doubt that active mental exercise changes the brain through "plasticity" but I have to wonder if we have to sign up for the deal ("save 20% and get free ground shipping!") with this specific technique to achieve this. Perhaps signing up for a book club, memorizing poetry, and playing chess daily, would accomplish similar results. I would like to see what the evidence has to say about this. His website is interesting to look at, has a few mental exercises to check out, the style of which I think really is quite positive and imaginative. I will be curious to see if his approach--and variations of it-- could be specifically helpful in treating disorders such as autism. But I don't see good clinical data out there yet.

As an amateur musician, I have found that "ear training" is probably the most important, but often least taught or practiced, form of mental development for improving musicianship. Merzenich's exercises clearly focus on "ear training" as a significant component. Here's his website for you to check it out yourself: http://bfc.positscience.com/

Here's a link to a program you can acquire, designed for music students, which develops musical ear-training ability much more thoroughly, in my opinion (I recommend this to all musicians): http://www.earmaster.com/

Tuesday, March 10, 2009

Neuroplasticity

This is an important book which I highly recommend:
The Brain that Changes Itself, by Norman Doidge (Penguin, 2007).

Doidge is a psychoanalyst who has done a fine job compiling evidence from recent neuroscience research, and from some older but neglected neuroscience research, that the brain has a tremendous capacity--a capacity which is arguably its most basic, core, innate quality-- for change and adaptation.

The idea of the brain as permanently "hard-wired" is refuted, with solid evidence.

Many of these ideas I have always felt to be obvious truths. For example, it seems an obvious necessity that the brain would have to build new connections in order to form any new thought, experience any new feeling, store any new memory, learn any new skill. But the degree to which whole areas of the brain can "re-wire" themselves is extremely interesting, and the evidence Doidge presents is very convincing.

Also, it has always been an obvious truth to me that any kind of sensitive neuroimaging device would of course demonstrate changes following a successful course of therapy (or of any other sort of learning or substantive life change).

The therapeutic applications based on this book are numerous, here are a few I can think of:

1) structured, intensive practice could lead to far greater effects than what has previously been assumed. The brain itself, as well as people in society, informed by culturally-based attitudes, tend to "work around" problems if the situation allows, whereas it can be the case that the problems themselves can be solved directly under the right conditions. For example, if an English-speaking person moves to a small town in a foreign country, that person will quickly learn that new foreign language, if it is necessary in order to survive. But if there are numerous English speakers in that small town, that person may not learn much of the new language at all.
We may need a type of immersive, constrained experience in order to compel our brain to develop a new faculty.

2) structured, intensive activities that have become part of a cultural norm (e.g. internet use, TV watching, etc.) could substantially alter the brain's connectivity and functionality, to optimally adapt to these new media. This could serve us well, culturally--but it may come at a cost of reduced functionality in media away from the TV or internet, particularly with respect to sustained attention, other intellectual and emotional faculties, and various types of social interaction.

3) Addictive processes are fed by the brain's capacity to adapt, to "re-wire" itself to expect a frequently reinforced behavioural pathway. "Un-learning" addictive behaviour once again may require a massive amount of work, akin to learning a new language.

--I have yet to review all of the references cited in this book. I think the primary source data will be important to go through in detail. There are some areas and claims that I think may possibly be overstated, in my opinion. But first I would like to review the evidence directly. I actually find the term "neuroplasticity" somewhat annoying, especially when therapeutic ideas are labeled "neuroplasticity-based treatments", etc. --I would say in response that ALL therapy, of ANY sort, is of course "neuroplasticity-based", so such lingo is unnecessary, and rings of salesmanship to me (indeed, there are several corporate ventures mentioned in the book). What matters most is the new types of therapeutic ideas that have been conceived by some of the researchers cited in the book, and how well they can work for very entrenched problems.


In the meantime, I do recommend Doidge's book highly.

Friday, March 6, 2009

Physicians in need of help

There is a high incidence of psychiatric problems in the medical community. Physicians may have a difficult time finding help. There are a variety of reasons for this, the most common of which is that the sources of help may all involve people the physician knows personally.

In BC we have something called the "physician health program", which is a resource especially for physicians in need of help. Here is the website:
http://www.physicianhealth.com/

Hopefully other communities have similar programs.

If a hospital admission is needed, it may be desired to arrange this in a different place, if privacy or confidentiality issues are major concerns.