Wednesday, April 13, 2011

Vitamin B12

A reader recently sent in a comment wondering about the possible role of vitamin B12 supplementation in psychiatry.

Here's a brief review of the literature:
http://www.ncbi.nlm.nih.gov/pubmed/21191533     --a small case report of b12-deficient individuals responding better to antidepressants after b12 supplementation.

http://www.ncbi.nlm.nih.gov/pubmed/20976769
--survivors of stroke who took folic acid 2mg/d, b6 25 mg/d, and b12 0.5 mg/d had slightly lower rates of depression; there was an impressive 7 year follow-up period


http://www.ncbi.nlm.nih.gov/pubmed/20716710
this cross-sectional study using a diet questionnaire found an association between dietary folate & b6 and lower rates of depression in a sample of over 6000 adolescents; no association was found regarding b12.  

http://www.ncbi.nlm.nih.gov/pubmed/20519557
a study from the American Journal of Clinical Nutrition, which showed a relationship between higher folate and b12 levels, and lower rates of depression, over 7 years of follow-up.

http://www.ncbi.nlm.nih.gov/pubmed/19175490 
another study finding an association between low b12 & folate levels and higher rates of depression.  Here, the b12 association was specifically for women. Looking more closely at the data, I find that the results are not overwhelmingly strong or convincing; I suspect there could be many confounding factors influencing the association.

http://www.ncbi.nlm.nih.gov/pubmed/18854539
this is an important study from JAMA showing that high dose folate, b6, and b12 supplements did not improve the course of dementia.  Furthermore, 28% of the vitamin group experienced depression, compared to  18% of the placebo group.

http://www.ncbi.nlm.nih.gov/pubmed/18557664this study from the Journal of Clinical Psychiatry showed very little protective effect of vitamin b6, b12, and folate supplementation to prevent depression in older men.  However, I see the vitamin group did slightly better than the placebo group, but not well enough to meet criteria for statistical significance.


In summary, there is a little bit of evidence of benefits from b12 in psychiatry, but the results are not overwhelmingly strong unless there is evidence of deficiency.  It is worthwhile to have B12 levels checked.  It appears not to be dangerous to take supplements; I suppose it is reasonable to aim for the higher part of the recommended serum levels, and to adjust any supplementation accordingly.  Having said that, I acknowledge the possibility that some individuals may have a more beneficial effect from b12 supplementation, perhaps there could be selected cases in which this could act synergistically or as an augmentation with other treatments for depression, or perhaps there could be cases of subtle deficiency.

B12 deficiency is not uncommon; this can occur due to malabsorption (as in pernicious anemia or bowel disease), or due to dietary deficiency (e.g. in vegans).  If the cause of low b12 is malabsorption, is may be necessary to have b12 injections.  Once again, it is important to have b12 levels checked, and make decisions about supplementation if the level is low.

Tuesday, February 15, 2011

Looking at affected body parts reduces pain

Here's an interesting little study showing that acute physical pain is diminished in intensity when one is looking at the affected body part;   if this body part is artificially made to look larger, then the subjective pain is reduced even further. 
http://www.ncbi.nlm.nih.gov/pubmed/21303990

 In applying this type of idea to psychological pain, I guess one could say that "looking at the affected body part" could translate to discussing the problem in a therapeutic dialog. 

A limitation of the study, and with pain studies in general, is that a brief intervention for an acute pain may not necessarily be equivalently helpful as a prolonged intervention for a chronic pain.  In fact, some effective physical treatments for acute pain potentially exacerbate a chronic or recurrent pain disorder (e.g. using opiates to treat mechanical back pain or migraine). 

However, I believe that studies of this type do illustrate that simple, brief psychological techniques can be surprisingly powerful in modulating perceptions or sensation.  

Working memory exercises for treating addictions?

Here's a link to an interesting article from Biological Psychiatry this month:
http://www.ncbi.nlm.nih.gov/pubmed/20965498

It is based on the notion that the decision to engage in an addiction is often made based on a short-term, possibly impulsive, analysis of benefits and risks; consequently, longer-term risks or benefits associated with the behaviour are undervalued.  This phenomenon is termed "delay discounting."   Resistance to delay discounting could be considered a cognitive faculty that would help, on an intellectual level, with making a healthy decision in the face of strong impulses in the moment.

The authors note a relationship between addictive disorders and increased delay discounting.  They also note a previously described relationship between delay discounting and reduced working memory function. 

Based on these relationships, they did a controlled study of persons with stimulant addiction, in which the active group did a set of memory training exercises for 1-2 months. They found that the memory exercises led to improved (reduced) delay discounting.


This study does not show that memory exercises directly improve the course of addictive disorders; but it does present a promising therapeutic idea which I think is currently underutilized in the therapeutic community, not only for addictions but for other types of problems.

Cognitive exercises could have a variety of benefits for various psychological problems:
1) the improvement one would see with practice could help with self-esteem
2) arguably, the exercises would favourably alter the balance between executive function and visceral, limbic emotional drives (which could often be turbulent or disruptive)
3) the exercises could be an introduction to the various mental and physical disciplines required to effect psychological or behavioural change

In terms of the specific exercises used in this study, I do think that the number of practice sessions was far too small.  I believe that most psychologically beneficial activities start to show substantial results after 50-100 hours of practice.  This study  used only a maximum of 15 training sessions.  The memory practice itself could have been organized in a more engaging, game-like manner.  I think of some quite unique working memory games from the lumosity.com website, which tap into a type of activity most people would rarely work on directly, but yet are quite entertaining and allow gradual progress.

In summary, this was an interesting article looking at the promising theme of using cognitive training exercises as part of the  treatment of  a psychological problem.  This is a relatively new idea, showing up only a few other times so far in the research literature.

Monday, January 31, 2011

Omega-3 deficiency and low dietary omega-3 to omega-6 ratio may exacerbate depression and reduce neuroplasticity

Here's an interesting update on the dietary fatty acid issue, as it pertains to mood disorders and neuroplasticity:
http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.2736.html

This article, published in Nature Neuroscience (January 30, 2011), is an example of some good research being done by a group at the University of Bordeaux in France.  They demonstrate substantial negative neurophysiological changes in mice as a result of an omega-3 deficient diet.  It is interesting to note that the brain's endocanniboid system is specifically affected by omega-3 deficiency, according to this research.

This is further evidence supporting the importance of attending to a healthy diet, in maintaining optimal mental health.  Omega-3 fatty acids are one element of a healthy diet.  While omega-6 fatty acids are also needed in the diet, these lipids behave to some degree competitively with omega-3.  Therefore,  the ratio of dietary omega-3 to omega-6 is is very important.  Western diets tend to have an unhealthy ratio of these lipids, due to excessive omega-6. 

An ongoing issue of debate has to do with whether plant sources of omega-3 (primarily ALA) are as useful as fish sources (DHA and EPA).  Existing evidence shows that DHA and EPA are more important.  ALA can be converted in the body to DHA and EPA, but the efficiency of this may vary from person to person.

Wikipedia has a nice review of this subject: http://en.wikipedia.org/wiki/Omega-3_fatty_acid
but some of the sources are less than ideal.

It is interesting to consider that the DHA/EPA issue is not a "micronutrient" issue.  They could be considered  "macronutrients."  The solid mass of the brain consists mostly of lipids (60-80 % of the non-aqueous mass); DHA and EPA  make up over 10% of this lipid mass, which is a very high concentration.


Here's a link to a paper which quantifies the  high fractions of omega-3 lipids in brain mass:
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=921064   --this paper also showed that dietary changes substantially altered the proportion of omega-3 lipids in brain tissue

Monday, January 24, 2011

"Outlier": The causes of high achievement

Outlier by Malcolm Gladwell, is a brilliant book about the causes of success, outstanding achievement, and personal greatness.

Gladwell describes a variety of interesting life stories, of people with outstanding ability or outstanding achievement, then looks carefully at the factors leading to these successes.

He does not claim that "inborn traits" or hereditary factors are unimportant.  But he shows quite convincingly that inborn talents correlate with achievement only to a certain point.  Individuals with extreme talents tend not to achieve more than those with merely "sufficient" talents. A recurring theme in this book, shown through one example after the next, is that the simple stories many people might have, to account for a person's great achievements, are often appealing and believable, but are in fact often inaccurate or at the very least incomplete.

He shows that various situational biases can have a profound, snowballing effect on the course of successfulness in a person's life.  A trite detail such as birthdate can lead to a cascade of advantages or disadvantages for athletes, which then accumulate over many years (his example is of successful hockey players being much more likely to have an early birthday--if you're born in December, this is an instant disadvantage, as you will be a little bit smaller and weaker on average compared to your teammates, therefore the older players will tend to outperform you, leading to a smaller chance of  you being noticed or advanced to a more challenging team, or to be deemed "gifted" and given more ice time, etc.)  

He emphasizes the role of thousands of hours of intensive practice being required to master a skill.  Those who have 10 000 hours of practice under their belt early on in their lives--particularly if some serendipitous quirk of fortune allowed them to be one of the only individuals, or one of the first, to gain this experience-- have a strong chance of succeeding spectacularly in their fields.  He gives examples such as Bill Gates, or the Beatles, or some of the most successful New York lawyers doing a particular type of law. 

One of the psychologists cited in this book,  who has studied the area of "exceptional achievement" is AK Ericsson, who generally argues that "extended, intense practice"  is the primary determinant of elite performance, as opposed to inborn talent.  The ability to do this type of practice, of course, requires or is greatly facilitated by, motivational resources as well as environmental opportunity, parental support, a culture which favours such as endeavour, etc.) Here are some references to articles of his:
http://www.ncbi.nlm.nih.gov/pubmed/17905932
http://www.ncbi.nlm.nih.gov/pubmed/17642130
I suspect that heredity is quite relevant, but may manifest itself in many ways aside from what many people might assume.  Factors that could be considered at first glance to be a disadvantage, either hereditarily or environmentally, may, in the world of successfulness, end up being compelling advantages.

Guillermo Campitelli is another excellent researcher in this field; here's a reference to one of his recent papers: http://www.ncbi.nlm.nih.gov/pubmed/17201516.  The evidence here, looking specifically at chess players as a model of acquiring expertise, affirms the extreme importance of thousands of hours of  practice, but also recognizes that some players improve much more than others with the same amount of practice.  This is probably the influence of inherited talent.  Maybe there could be other hidden variables, including family or cultural factors.   He suggests that the age at which the practice begins is another important variable.  

It should be noted that, in this literature, "deliberate practice" refers to a type of activity which is specifically directed towards performance improvement, is adequately difficult, has feedback about performance, and which has opportunity to correct errors.  This differs from "ordinary" work experience, which may be quite a bit less intense and much less geared towards improving skills.  I suspect that the quality of "deliberate practice" may vary quite a bit, depending on the degree of immersion, concentration, energy, engagement, and meaningfulness there is in the action.  I wonder if enjoyment of the practice is a major variable too, I would be interested to see if some of these researchers would look at this.  If someone finds their 100 hours of practice meaningful and enjoyable, I have to wonder if they might advance much more than someone whose 100 hours were a drudgery.    

Another excellent angle of discussion in Gladwell's book has to do with understanding a person's cultural background and childhood developmental history, as extremely important determinants of success.   This leads to discussions about opportunity, pedagogical technique and policy, etc.  Sometimes cultural or developmental factors cause individuals to lack a certain skill necessary to succeed, or put individuals at risk of recurrent severe problems or frustrations.  Good examples are given, including the story of a profoundly gifted intellect who was never able to share his talents; and of highly trained pilots who were too quietly respectful of authority to be able to proactively use strong assertive social skills to prevent an aviation disaster.

I'll add to this post later on, to expand some thoughts about achievement and success.  In the meantime, I think Outlier is a worthwhile and entertaining read.