Studies comparing normal reading and dyslexic children often take a snapshot approach, comparing brain function at specific ages. However, these studies don’t tell us how these differences fit into the developmental picture. Are dyslexics following the same developmental course as normal readers, just at a different rate? Or do dyslexic brains develop in a
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Shaywitz BA, Skudlarski P, Holahan JM, Marchione KE, Constable RT, Fulbright RK, Zelterman D, Lacadie C, & Shaywitz SE. (2007) Age-related changes in reading systems of dyslexic children. Annals of neurology, 61(4), 363-70. PMID: 17444510
Last month, in response to some truly despicable activities by animal rights zealots, I wrote a series of posts about how animal rights activists target even researchers' children and appear to fetishize violence. This simply continued a string of posts that I've done over the years, the longest (and, in my not-so-humble-opinion, the best) deconstructs a lot of the bad scientific arguments used by animal rights activists to claim that animal research is useless, or nearly so, as well as other arguments made by extremists. One of the key points emphasized in these responses is that, regardless of their shortcomings, animal models for many conditions provide useful data, have lead to medical breakthroughs, and are better than any of the alternatives currently touted by animal rights activists. Someday, for example, cell culture and computer models may allow us to replace the use of animals for a lot of studies.
Not surprisingly, then, I've had a few readers make me aware of a recently released study published in PLoS Biology, entitled Publication Bias in Reports of Animal Stroke Studies Leads to Major Overstatement of Efficacy. I actually knew about this study last week, because I'm on the PLoS press list. But the study was embargoed until Monday night, and for some reason I let Mike Adams distract me from taking on a real scientific study. On the other hand, it's always a good time to have some fun with our favorite woo-meister of all. It's just fortunate that my readers didn't let me forget about this study.
Science-based medicine depends upon preclinical studies in cell culture and animal models in order to determine disease mechanisms and, just as importantly, to test new therapies before testing them in humans. I've pointed out before that animal studies don't always correlate as cleanly as we would like with human studies. However, for all their imperfections, animal studies can allow us to study phenomena that require three dimensional structure with all the different types of cells normally in the organ in question. One example I like to use is the study of tumor angiogenesis, which requires complex interactions between the tumor cells, vascular cells, and the stroma. Although I'm aware of models that examine endothelial cells, fibroblasts, and tumor cells in three dimensional coculture that can produce some pretty cool results, but they are still just cells in dishes. They're cells in dishes using sophisticated culture systems, but cells in dishes nonetheless.
It's thus of great interest to know what the predictive capability of animal models is. In the case of this study, the authors performed a metaanalysis of animal models of acute ischemic stroke to try to estimate the effect of publication bias on the reported results. As you may be aware, publication bias is an insidious generalized form of bias that creeps into the medical literature because studies showing a positive result are more likely to be published than studies that show a negative result. Also known as "the file drawer effect" (where negative studies tend to be left in the "file drawer" rather than to be published, publication bias is a problem in the clinical trial literature, so much so that clinical trial registries such as Clinicaltrials.gov, have been set up to make sure that the results of all human clinical trials see the light of day. The authors lay out this problem right in the introduction: Read the rest of this post... | Read the comments on this post...... Read more »
Sena, E., van der Worp, H., Bath, P., Howells, D., & Macleod, M. (2010) Publication Bias in Reports of Animal Stroke Studies Leads to Major Overstatement of Efficacy. PLoS Biology, 8(3). DOI: 10.1371/journal.pbio.1000344
Figure 1: Does Mickey feel empathy?
It probably depends on how you define empathy. Empathy, by any definition, implies emotional sensitivity to the affective state of another. Sometimes the empathy response is automatic or reflexive, like when babies start to cry upon hearing another baby crying. Sometimes a strong cognitive component is required, such as for [...]... Read more »
Jeon D, Kim S, Chetana M, Jo D, Ruley HE, Lin SY, Rabah D, Kinet JP, & Shin HS. (2010) Observational fear learning involves affective pain system and Ca(v)1.2 Ca(2 ) channels in ACC. Nature neuroscience, 13(4), 482-8. PMID: 20190743
Just a bit of self-promotion about my last paper. Despite the superiority of longitudinal vs cross-sectional studies, the dynamics of drug action are poorly explored in pre-clinical studies. Little is known about how drugs affect the activity of their intended target over time. Here, we used a longitudinal imaging approach to accurately follow the state of transcriptional activity of one drug target (the estrogen receptor) in 8 anatomical areas of living ERE-luc reporter mice over 21 consecutive days of hormone replacement therapy with 10 different Selective Estrogen Receptor Modulators (SERMs).
This is a 2006: I checked the accuracy of the algorithm measuring the area under the curve by weighing small pieces of paper. My bench-mates are still laughing...We found that each SERM caused tissue-specific oscillations on ER transcriptional activity which were predictive of the drug structure (after rational extraction of meaningful molecular descriptors).
For more than one century, the measure of drug structure-activity relationships has been based on mathematical equations describing the interaction of the drug with its biological receptor. This is now obsolete, as 'binding' does not necessarily spell 'function'. Here, a systematic study of spatio-temporal effects is proposed as a measure of drug efficacy for the classification of pharmacologically active compounds.We conclude that the use of reporter mouse facilitates the identification of SERMs able to mimic the physiological estrous cycle and anticipates the possibility of a reverse approach in medicinal chemistry where the space-temporal plot of target activity drives the identification of subtle structure-activity relationships.
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Rando, G., Horner, D., Biserni, A., Ramachandran, B., Caruso, D., Ciana, P., Komm, B., & Maggi, A. (2010). An Innovative Method to Classify SERMs Based on the Dynamics of Estrogen Receptor Transcriptional Activity in Living Animals Molecular Endocrinology, 24 (4), 735-744 DOI: 10.1210/me.2009-0514
Rando G, Biserni A, Ciana P, & Maggi A (2010). Profiling of drug action using reporter mice and molecular imaging. Methods in molecular biology (Clifton, N.J.), 602, 79-92 PMID: 20012393
Rando G, Arca S, Casiraghi E, Campadelli P & Maggi A (2009). Automatic Segmentation of Mouse Images. Proc 10th European Congress of International Society for Stereology, Bologna, Italy, 2009 link: abstract
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Rando, G., Horner, D., Biserni, A., Ramachandran, B., Caruso, D., Ciana, P., Komm, B., & Maggi, A. (2010) An Innovative Method to Classify SERMs Based on the Dynamics of Estrogen Receptor Transcriptional Activity in Living Animals. Molecular Endocrinology, 24(4), 735-744. DOI: 10.1210/me.2009-0514
Nope, not even close, although I doubt it will stop big food from marketing Activia yogurt and others as a solution for expanded waistlines.... Read more »
Kadooka, Y., Sato, M., Imaizumi, K., Ogawa, A., Ikuyama, K., Akai, Y., Okano, M., Kagoshima, M., & Tsuchida, T. (2010) Regulation of abdominal adiposity by probiotics (Lactobacillus gasseri SBT2055) in adults with obese tendencies in a randomized controlled trial. European Journal of Clinical Nutrition. DOI: 10.1038/ejcn.2010.19
Physician burnout and job dissatisfaction are concerning as physicians in the United States have more patients to see in less time with fewer resources. Physician burnout is associated with job absenteeism, leaving the profession altogether, poor quality of care, and medical errors. Now, a recent study published in the Journal of the American Medical Association [...]... Read more »
Krasner, M., Epstein, R., Beckman, H., Suchman, A., Chapman, B., Mooney, C., & Quill, T. (2009) Association of an Educational Program in Mindful Communication With Burnout, Empathy, and Attitudes Among Primary Care Physicians. JAMA: The Journal of the American Medical Association, 302(12), 1284-1293. DOI: 10.1001/jama.2009.1384
Utsugi-Ozaki, M., Bito, S., Matsumura, S., Hayashino, Y., Fukuhara, S., & , . (2009) Physician Job Satisfaction and Quality of Care Among Hospital Employed Physicians in Japan. Journal of General Internal Medicine, 24(3), 387-392. DOI: 10.1007/s11606-008-0886-4
From a systematic review of 10 randomized clinical trials: chocolate has blood pressure lowering capacity. Dark chocolate has a high content of flavanols. Flavonoids are the part of chocolate important for health benefits. They can also be found in high concentrations in certain fruits and vegetables. In the context of human nutrition, certain teas, grape [...]
Related posts:Have Your Dark Chocolate with Green Tea
How Much Chocolate is good for your Health?
A Chocolate Bar A Day Keeps the Doctor Away
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Desch, S., Schmidt, J., Kobler, D., Sonnabend, M., Eitel, I., Sareban, M., Rahimi, K., Schuler, G., & Thiele, H. (2009) Effect of Cocoa Products on Blood Pressure: Systematic Review and Meta-Analysis. American Journal of Hypertension, 23(1), 97-103. DOI: 10.1038/ajh.2009.213
I think that label has to be one of the most feared amongst the people I see with chronic pain. To be judged as being obsessed about nonexistant illnesses when actually having pain every day must be incredibly difficult to cope with. At the same time, being anxious about health and having mistaken beliefs about [...]... Read more »
Abramowitz, J., Deacon, B., & Valentiner, D. (2007) The Short Health Anxiety Inventory: Psychometric Properties and Construct Validity in a Non-clinical Sample. Cognitive Therapy and Research, 31(6), 871-883. DOI: 10.1007/s10608-006-9058-1
Lifestyle is the most important factor for medical students in their specialty choice. With specialty choice in this research is meant the distinction between person oriented and technique oriented specialty.
person-oriented specialties are considered to be family practice, internal medicine, obstetrics and gynecology, pediatrics, physical medicine and rehabilitation, and psychiatry, whereas technique-oriented specialties are anesthesiology, dermatology, [...]
Related posts:Emotional Intelligence and Medical Specialty Choice
Speciality Choice of Medical Students, Impact of Clerkship
Unprofessional Online Content By Medical Students
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Borges, N., Manuel, R., Duffy, R., Fedyna, D., & Jones, B. (2009) Influences on specialty choice for students entering person-oriented and technique-oriented specialties. Medical Teacher, 31(12), 1086-1088. DOI: 10.3109/01421590903183787
Manuel, R. (2009) Person-Oriented Versus Technique-Oriented Specialties: Early Preferences and Eventual Choice. Medical Education Online. DOI: 10.3885/meo.2009.Res00284
Scene from Paranormal ActivityAfter a young, middle class couple moves into what seems like a typical suburban “starter” tract house, they become increasingly disturbed by a presence that may or may not be demonic but is certainly most active in the middle of the night.Especially when they sleep. Or try to.A new case study in Cortex by neurologist Dr. Fabienne Picard (2010) reports on a patient who experienced unusual phenomena during epileptic seizures. She had the convincing sense that several familiar people (family members) were standing before her. This experience of a "sensed presence" is a classic trope in movies with supernatural themes (e.g., Carnival of Souls [available at Internet Archive], The Haunting [trailer for the 1963 version], Poltergeist, Dark Water), but it's generally attributed to ghosts and not to seizure activity.Here's the case report:A 62-year-old right-handed woman of normal psychiatric history presented a simple focal epileptic seizure including a complex sensation characterized by feeling the presence of several members of her family in the immediate environment, associated with paresthesia of the right hemibody (excluding the face). The feeling of presences and the paresthesia (numbness) appeared concomitantly and lasted in total several minutes. The episode occurred while she was sitting alone on the sofa of her living room and immediately felt the presence of four persons in her frontal space. She did not see or hear these persons (no visual or auditory hallucinations), but felt vividly their presence in her peripersonal [within reach] and near extrapersonal space [just outside of reach]. She “recognized” them as close family members. Closest was her grand-daughter who was sitting on the floor immediately in front of her, without any left or right lateralization in relation to her body, whereas the three other persons, her daughter and two other grand-children, were experienced to be localized at a distance of several meters. ... This highly vivid and convincing feeling of presences was described by the patient as deeply pleasant, although she guessed that it was not possible that they were really there, as she was alone just before. ... She was treated with pregabalin (300 mg/day) and there was no recurrence of simple or complex partial seizures and no further feeling of presences.MRIs revealed abnormal findings due to a right hemisphere subcortical stroke 10 months before the episode (Fig. 1A). The patient's stroke affected a portion of the basal ganglia (the putamen and the globus pallidus) and a large white matter tract within (the internal capsule). Left hemisphere findings in the insular cortex were also apparent, and this was the likely seizure focus. Strokes are known to increase the incidence of seizures: in one study 8.6% of those with ischemic stroke [occlusion of blood supply] and 10.6% of those with hemorrhagic stroke [bleed] had one or more seizures within a year (Bladin et al., 2000).Fig. 1 (adapted from Picard, 2010). FLAIR coronal MR images of the patient. (A) two days after a right capsulo-lenticular haemorragic stroke. (B) ten months later, at the time of the episode of feeling of presence. In addition to the right capsulo-lenticular sequela extending to the insula, a hypersignal is visible in the white matter/grey matter border of the left insular region [already visible in (A)], as well as a diffuse corticosubcortical atrophy, predominating in the right hemisphere, and a leukoencephalopathy [white matter disease]. Picard (2010) thinks this particular case is unique and not a more typical disorder of body perception:Most authors consider the feeling of a presence (FP) as a disorder of own body perception, an illusory reduplicative phenomena involving the self. Thus FP would be akin to the three main forms of autoscopic phenomena (seeing a double of oneself) which include a) out-of-body experience. The subjects appear to see themselves and the world from a location above their physical body. The self is localized outside one's physical body (disembodiment); b) autoscopic hallucination, which consists of seeing one's body in extracorporeal space (as a double) without disembodiment; and c) heautoscopy, an intermediate form between out-of-body experience and autoscopic hallucination.Instead, the felt presence was more akin to a "hallucination" for known people going about normal daily activities. Nonetheless, involvement of the insula, important for interoceptive awareness of bodily states (Craig, 2009), is still suggestive of a disruption in the sense of self and its interaction with the external world.To end our story, the patient's experience of a sensed presence did not recur once her seizures were controlled with medication. A short neurological horror film resolved by prescription of an anticonvulsant drug might not be a strong sell in Hollywood.ReferencesBladin CF, Alexandrov AV, Bellavance A, Bornstein N, Chambers B, Coté R, Lebrun L, Pirisi A, Norris JW. (2000). Seizures after stroke: a prospective multicenter study. Arch Neurol. 57:1617-22.Craig AD. How do you feel--now? The anterior insula and human awareness. (2009). Nat Rev Neurosci. 10:59-70.... Read more »
Picard, F. (2010) Epileptic feeling of multiple presences in the frontal space. Cortex. DOI: 10.1016/j.cortex.2010.02.002
More than 10% of women experience either major or minor depression six weeks after giving birth. Postpartum depression (PPD) leads to significant biological, social, psychological, and economic consequences for the mother, the child, and the family. Clinically and cost-effective treatments are available for PPD, but less than half of PPD cases are ever diagnosed. Unfortunately, [...]... Read more »
Austin MP, Priest SR, & Sullivan EA. (2008) Antenatal psychosocial assessment for reducing perinatal mental health morbidity. Cochrane database of systematic reviews (Online). PMID: 18843682
Hewitt, C., & Gilbody, S. (2009) Is it clinically and cost effective to screen for postnatal depression: a systematic review of controlled clinical trials and economic evidence. BJOG: An International Journal of Obstetrics . DOI: 10.1111/j.1471-0528.2009.02148.x
Paulden, M., Palmer, S., Hewitt, C., & Gilbody, S. (2009) Screening for postnatal depression in primary care: cost effectiveness analysis. BMJ, 339(dec22 1). DOI: 10.1136/bmj.b5203
At last weeks investor meeting held by Roche in downtown Wall Street, the Board reviewed the pipeline opportunities in a number of areas. Earlier this week I wrote about the non-oncology pipeline and today will form an overview of the...... Read more »
Baselga, J., Gelmon, K., Verma, S., Wardley, A., Conte, P., Miles, D., Bianchi, G., Cortes, J., McNally, V., Ross, G.... (2010) Phase II Trial of Pertuzumab and Trastuzumab in Patients With Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer That Progressed During Prior Trastuzumab Therapy. Journal of Clinical Oncology, 28(7), 1138-1144. DOI: 10.1200/JCO.2009.24.2024
Makhija, S., Amler, L., Glenn, D., Ueland, F., Gold, M., Dizon, D., Paton, V., Lin, C., Januario, T., Ng, K.... (2009) Clinical Activity of Gemcitabine Plus Pertuzumab in Platinum-Resistant Ovarian Cancer, Fallopian Tube Cancer, or Primary Peritoneal Cancer. Journal of Clinical Oncology, 28(7), 1215-1223. DOI: 10.1200/JCO.2009.22.3354
Well, in fairness, Jesus' twelve Apostles should also share in the blame.
An incredibly quirky and yet fascinating study was just published in the International Journal of Obesity which investigated the size of the food and plates that have been depicted in paintings of Jesus' Last Supper over the last 1000 years.
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Wansink, B., & Wansink, C. (2010) The largest Last Supper: depictions of food portions and plate size increased over the millennium. International Journal of Obesity. DOI: 10.1038/ijo.2010.37
Last week during Weird Science, Sci got to hear a lot more about people's urine odors than she probably ever REALLY wanted to know.
But hey, why be shy?
And so you may imagine that urine and fluids have been on Sci's mind a little bit lately. Another thing has also been on Sci's mind: the sheer amount of coffee that she has been drinking.
She may be actually jonesing for her late PM dose right about now...
Sci has heard from many quarters that Coffee makes you pee, and that this is because caffeine is a diuretic. On the other hand, Sci has also heard that coffee only makes you pee because it's a liquid and you're drinking it, rather than any specific diuretic properties. So which is it?
This question is of great concern to Sci for several reasons. First, Sci drinks a lot of coffee. Second, Sci is a distance runner, and likes to compete in races. She's been reading a lot lately about how caffeine just before a workout or race is good, and can increase your performance. However, IF caffeine is ALSO a diuretic, this is something to keep in mind, because there is NOTHING worse than getting halfway through a 30K (18.5 miles, so say you're 9 miles in or so), and realizing that you REALLY have to pee (well, ok, maybe realizing you have diarrhea, or are going to vomit, pass out, or have a heart attack). Races always talk about having port-o-johns, but at the side of the trail? HAHAHAHAHAHA. No. Sci doesn't mind peeing in the woods, of course, but it wastes some seriously valuable time, especially in the shorter races, when a 30 second bathroom break WILL kill your chances of a win.
And so, Sci was curious, diuretic or not? She decided to take a look around.
Maughan and Griffin. "Caffeine ingestion and fluid balance: a review" Journal of Human Nutrition and Dietetics, 2003.
Riesenhuber et al. "Diuretic potential of energy drinks." Amino Acids. 2006.
Armstrong et al. "Fluid, electrolyte, and renal indices of hydration during 11 days of controlled caffeine consumption." Int J Sport Nutr Exerc Metab. 2005.
Eeek! Hold on, pee break!
*phew* Read the rest of this post... | Read the comments on this post...... Read more »
Maughan RJ, & Griffin J. (2003) Caffeine ingestion and fluid balance: a review. Journal of human nutrition and dietetics : the official journal of the British Dietetic Association, 16(6), 411-20. PMID: 19774754
Armstrong LE, Pumerantz AC, Roti MW, Judelson DA, Watson G, Dias JC, Sokmen B, Casa DJ, Maresh CM, Lieberman H.... (2005) Fluid, electrolyte, and renal indices of hydration during 11 days of controlled caffeine consumption. International journal of sport nutrition and exercise metabolism, 15(3), 252-65. PMID: 16131696
I know it’s actually Friday Funnies day, but before I go there I want to explore something I’ve been observing for a while. Over the past four or five years, the TSK (Tampa Scale for Kinesiophobia) has been a really popular instrument for identifying and monitoring pain-related anxiety and avoidance. It has been found to [...]... Read more »
CARLETON, R., & ASMUNDSON, G. (2009) The Multidimensionality of Fear of Pain: Construct Independence for the Fear of Pain Questionnaire-Short Form and the Pain Anxiety Symptoms Scale-20. The Journal of Pain, 10(1), 29-37. DOI: 10.1016/j.jpain.2008.06.007
Ostelo RW, Swinkels-Meewisse IJ, Knol DL, Vlaeyen JW, & de Vet HC. (2007) Assessing pain and pain-related fear in acute low back pain: what is the smallest detectable change?. International journal of behavioral medicine, 14(4), 242-8. PMID: 18001240
There's a rather timely article in the current American Journal of Psychiatry: Assuring That Double-Blind Is Blind.Generally, when the list of the authors' conflicts of interest (550 words) is nearly as long as the text of the paper (740 words), it's not a good sign, but this one isn't bad. Perlis et al remind us that if you do a double-blind placebo controlled trial:The blind may be compromised in a variety of ways, however, beginning with differences in medication taste or smell. Of particular concern may be the emergence of adverse effects, particularly when those adverse effects are known to be associated with a specific medication ... Indeed, when the degree of unblinding is assessed in antidepressant trials, multiple reports suggest that it is extensive: at least three-quarters of patients are typically able to correctly guess at their treatment assignment. The point of a placebo-controlled trial is that neither the patients nor their doctors know whether they're getting the placebo or the real drug. Hence the strength of the placebo effect should be the same in each group, allowing the "real" drug effect to be measured.But if the drug causes side effects, as pretty much all do, then people could work out which group they're in by noticing whether they're feeling side effects or not. This might enhance the placebo effect in the drug group, and make the drug seem to work better than it really does. Or it might not. But the possibility that it might is worrying.This is called the active placebo effect. It's why I'm skeptical of claims that scopolamine and ketamine have rapid-acting but short lived antidepressant effects. I may be wrong, but while both of these drugs have been shown to work better than placebo, both have very pronounced subjective effects, so there's no chance the blind will have been intact.Whether the active placebo effect also underlies the efficacy of established antidepressants like Prozac is very controversial. There have been 9 trials comparing antidepressants to active placebos, i.e. drugs that have similar side effects to antidepressants and that should therefore help to preserve the blind. (The active placebos were all atropine which is basically the same as scopolamine.)The trials were reviewed by antidepressant critic Joanna Moncrieff et al who found that the overall effect size of antidepressants vs. active placebos was d = 0.39. That's not very high, although it's not too bad, and ironically it's actually higher than the effect that Moncrieff's friend and fellow Prozac-baiter Irving Kirsch found in his famous 2008 antidepressant vs. sugar pill placebo meta-analysis, d=0.32. So if you take that seriously, the active placebo effect plays no part in antidepressant efficacy. However the active placebo trials are mostly small and old, so to be honest, we don't really know.*A point that's often overlooked is that a drug could have an active placebo effect via having a "real" psychoactive treatment effect. Diazepam (Valium), for example, has basically no peripheral side effects at all: unlike scopolamine it doesn't cause dry mouth, nausea, etc. But it is a tranquillizer; it causes calmness and, at higher doses, sleep. They're pretty noticeable. So if you were to give a depressed person Valium and tell them that it's not only a tranquillizer, it's an antidepressant, then the active placebo problem would arise.In fact, any active drug will also produce active placebo effects - almost by definition, if you think about it. These may be hard to disentangle from the "real" effects. Say you're anxious about giving a speech so you take some diazepam hoping to feel calmer. A short while later you feel the lovely warm tranquillizing feeling setting in. Phew, you're calm now, anxiety's gone, the speech will be no worry. That thought might well be tranquillizing in itself. In other words the anti-anxiety effects of diazepam are partially driven by active placebo responses due to... the anti-anxiety effects of diazepam.*This leads onto another point. Suppose a drug has a genuine effect which improves some of the symptoms of a disease. Does that drug "treat" that disease? In a weak sense, yes, and it might be a helpful drug, but it's not a specific treatment. Morphine's very helpful in cancer, because it treats pain, but it doesn't cure cancer. Likewise insomnia is a symptom of depression, but we feel that in order to qualify as an antidepressant a drug has to treat the core symptoms: mood, anxiety, etc. rather than just being a sleeping pill.But suppose someone suffered from low mood and you gave them a treatment which stopped them feeling any moods or emotions. That solves their low mood problem: no mood, no problem. But is that a specific treatment for depression? It's a bit of a grey area, but many would say no.Many people say that this is exactly what SSRI antidepressants do: they blunt your emotions. That doesn't mean they're not helpful in depression: a lot of people find them very useful. I did. But then are they really "antidepressants", or just anti-mood? SSRIs are the drugs of choice not just for depression but also most anxiety disorders, and OCD, etc. In fact they work better in OCD than they do in depression, relative to placebo. So are SSRIs actually anti-obsessives that happen to be helpful in some cases depression? Good question.Here's Chris Rock on the issue of non-specific effects...*Perhaps an ideal clinical trial of a psychiatric drug should have 4 groups: the drug you're studying, another psychotropic (e.g. Valium), an active placebo with purely peripheral side effects, and sugar pills. But even then, if the antidepressant did better than the other 3 groups, a die-hard skeptic could say that maybe it just more effectively causing non-specific sedation, or blunting, or whatever, than the Valium. Ultimately, a randomized controlled trial can never prove that a psychotropic drug has a specific as opposed to a non-specific effect.So where do we stand? Does that mean we don't know what drugs do? No - unless we're some cloistered soul who only reads papers as opposed to talking to people, reading subjective reports, or taking drugs themselves. I know what alcohol does, not because I've read papers about it, but because I've drunk it. I've also been depressed and taken antidepressants, and for what it's worth, in my experience, some of the drugs currently marketed as antidepressants do have a specific anti-depression effect, although others don't. Overall, though, my view is that we know surprisingly little about what antidepressants actually do.Perlis RH, Ostacher M, Fava M, N... Read more »
Moncrieff J, Wessely S, & Hardy R. (2004) Active placebos versus antidepressants for depression. Cochrane database of systematic reviews (Online). PMID: 14974002
On an Australian study of retrospective cross-sectional surveys of parents whose children died of cancer at least one year previously.... Read more »
Heath JA, Clarke NE, Donath SM, McCarthy M, Anderson VA, & Wolfe J. (2010) Symptoms and suffering at the end of life in children with cancer: an Australian perspective. The Medical journal of Australia, 192(2), 71-5. PMID: 20078405
Over the next few months, Peter and I will be re-posting some of our favourite posts from our Obesity Panacea archives. The following article was originally posted on December 2, 2009.
Image by Mike Baird.
There is a surprising amount of controversy about the ability of physical activity to prevent the development of obesity. Sure, obese individuals tend to perform less physical activity than their lean counterparts, but that doesn't prove causation. And almost every week it seems that there is a news story reporting that the obesity epidemic is caused by diet. Period. If you believe these articles, physical activity plays a minor role, if any role at all. Some have even (erroneously) suggested that physical activity increases the risk of weight gain (for a thorough debunking of a recent TIME article on this subject, click here).
One of the problems of trying to untangle the role of physical activity in the development of obesity is that most studies use indirect measures of physical activity, like self-report questionnaires. Not surprisingly, there is a lot of error when people are reporting a socially-desirable behaviour like physical activity, as they tend to err on the positive side. And questionnaires also often give several fixed options, for example "Are you normally active for 15, 30, 45, or 60 minutes per day?". If you are active for 20 minutes per day, would you pick 15 or 30? Either way, it introduces a lot of error, which makes it very difficult to determine the specific role that your current physical activity levels play in the development of obesity down the road.
Read the rest of this post... | Read the comments on this post...... Read more »
Riddoch, C., Leary, S., Ness, A., Blair, S., Deere, K., Mattocks, C., Griffiths, A., Davey Smith, G., & Tilling, K. (2009) Prospective associations between objective measures of physical activity and fat mass in 12-14 year old children: the Avon Longitudinal Study of Parents and Children (ALSPAC). BMJ, 339(nov26 2). DOI: 10.1136/bmj.b4544
The survivors of the World War II atomic bombings of Hiroshima and Nagasaki may have considered themselves lucky, at least at first. Shortly thereafter, however, those who didn’t die from radiation poisoning learned that the radiation from the bombings placed themselves and their children at increased risk of cancer. Now, they can add heart disease [...]... Read more »
Little, M. (2010) Exposure to radiation and higher risk of circulatory disease. BMJ, 340(jan14 1). DOI: 10.1136/bmj.b4326
Research team finds brain abnormalities.
When it came to babies born to crack-addicted mothers, the media went overboard, creating a crisis in the form of an epidemic that never quite was. By contrast, when it came to babies born to alcoholic mothers, Fetal Alcohol Syndrome went unrecognized in the science and medical community until 1968.
Now comes a study on prenatal methamphetamine exposure in The Journal of Neuroscience, headed up by Elizabeth Sowell of the University of California, Los Angeles, with support from both the National Institute on Drug Abuse (NIDA) and the National Institute of Alcoholism and Alcohol Abuse (NIAAA.) The report garnered considerable media attention. “We know that alcohol exposure is toxic to the developing fetus and can result in lifelong brain, cognitive and behavioral problems,” Sowell said in a press release. “In this study, we show that the effects of prenatal meth exposure, or the combination of meth and alcohol exposure, may actually be worse.”
It makes sense that meth might effect the health of unborn children. There is a modest body of research to support the notion. The Sowell study points a finger at the caudate nucleus, a brain region involved with learning and memory. The study showed that the caudate nucleus of the meth-using group was reduced in size. “Identifying vulnerable brain structures may help predict particular learning and behavioral problems in meth-exposed children,” the press release optimistically states. And the potential problem is real enough: More than 16 million Americans have used meth, according to government numbers. An estimated 19,000 of these users are pregnant women.
But is this particular study a definitive one? The icing on the cake? To begin with, the press release from The Journal of Neuroscience admits to a major problem right up front: “About half of women who say they used meth during pregnancy also used alcohol, so isolating the effects of meth on the developing brain is difficult.” Even in cases of meth exposure only, there are a host of negative behavioral factors that often accompany meth addiction (bad nutrition, minimal health care, poor health) that can significantly effect fetal development.
The study team compared the MRI brain scans of 61 children: “21 with prenatal MA (methamphetamine) exposure, 18 with concomitant prenatal alcohol exposure (the MAA group), 13 with heavy prenatal alcohol but not MA exposure (ALC group), and 27 unexposed controls. While finding “striatal volume reductions,” as well as increases in the size of certain limbic structures in both groups with meth and/or alcohol exposure, the researchers conclude that striatal and limbic structures “may be more vulnerable to prenatal MA exposure than alcohol exposure.” However, that conclusion was apparently reached despite the fact that only 3 of the 61 children under study were born to mothers who did meth, and meth only, during pregnancy.
Furthermore, there is significant controversy over brain scan studies that measure gross anatomical changes in the size of specific brain regions, rather than brain region activity based on blood flow.
Is there other evidence for the danger of meth use during pregnancy? There is, but as is frequently the case, some of the best evidence comes from animal studies. A 2008 guinea pig study by Sanika Chirwa
showed neural damage to the hippocampus, another region involved in memory, in newborn animals with prenatal meth exposure. Furthermore, the newborn animals showed an impaired ability to distinguish novel objects from familiar ones.
In 2006, a study at Brown Medical School, published in Pediatrics , found that newborns exposed to meth during pregnancy were born “small for gestational age,” meaning they were born full-term, but smaller than babies not exposed to meth in utero. According to study author Barry Lester, “Children who are born underweight tend to have behavior problems, such as hyperactivity or short attention span, as well as learning difficulties.”
However, Lester added an important caveat in a Brown University press release : “I hope that the ‘crack baby’ hysteria does not get repeated. While these children may have some serious health and developmental challenges, there is no automatic need to label them as damaged and remove them from their biological mothers.”
Similar caution was urged by the authors of a 2009 report in the Journal of Developmental and Behavioral Pediatrics: “Efforts to understand specific effects of prenatal methamphetamine exposure on cognitive processing are hampered by high rates of concomitant alcohol use during pregnancy.”
In 2005, an open letter from the Center for Substance Abuse Research at the University of Maryland warned about the dangers of hyperbole, calling upon the media and public officials to “stop perpetuating ‘meth baby’ myths.” The Center argued that “The terms ‘ice babies’ and ‘meth babies’ lack medical and scientific validity and should not be used,” and requested that “policies addressing prenatal exposure to methamphetamines and media coverage of this issue be based on science, not presumption or prejudice.”
Sowell, E., Leow, A., Bookheimer, S., Smith, L., O'Connor, M., Kan, E., Rosso, C., Houston, S., Dinov, I., & Thompson, P. (2010). Differentiating Prenatal Exposure to Methamphetamine and Alcohol versus Alcohol and Not Methamphetamine using Tensor-Based Brain Morphometry and Discriminant Analysis Journal of Neuroscience, 30 (11), 3876-3885 DOI: 10.1523/JNEUROSCI.4967-09.2010
Smith, L., LaGasse, L., Derauf, C., Grant, P., Shah, R., Arria, A., Huestis, M., Haning, W., Strauss, ... Read more »
Sowell, E., Leow, A., Bookheimer, S., Smith, L., O'Connor, M., Kan, E., Rosso, C., Houston, S., Dinov, I., & Thompson, P. (2010) Differentiating Prenatal Exposure to Methamphetamine and Alcohol versus Alcohol and Not Methamphetamine using Tensor-Based Brain Morphometry and Discriminant Analysis. Journal of Neuroscience, 30(11), 3876-3885. DOI: 10.1523/JNEUROSCI.4967-09.2010
Smith, L., LaGasse, L., Derauf, C., Grant, P., Shah, R., Arria, A., Huestis, M., Haning, W., Strauss, A., Grotta, S.... (2006) The Infant Development, Environment, and Lifestyle Study: Effects of Prenatal Methamphetamine Exposure, Polydrug Exposure, and Poverty on Intrauterine Growth. PEDIATRICS, 118(3), 1149-1156. DOI: 10.1542/peds.2005-2564
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