Monday, May 9, 2011

Detecting faked ADHD in college students

Here's a neat little study that examined whether it was possible to distinguish between college students who had been diagnosed with ADHD, students who were asked to feign ADHD, and a group of control subjects who were asked to respond honestly. The authors used a bunch of different self-report measures and neuropsychological tests that are commonly used for a diagnosis of ADHD. They also administered several measures of feigning or what they called Symptom Validity Tests (SVTs).

The study was on the smaller side (29 ADHD, 30 feigners, and 14 controls), but the authors were nice enough to report effect sizes instead of relying on p-values alone. The controls were asked to respond as they normally would. Most of the subjects with previously diagnosed ADHD (usually determined by some fairly extensive evaluation at some point of time in their past) were on some sort of medication as well, and came in for the study after a 12-hour washout period. They were also asked to respond normally. Last was the group of feigners, who were given some information about ADHD compiled from a few hits from Google for them in advance. This group was asked to fake symptoms of ADHD throughout the experiment, but also cautioned to remember that they should perform at least as well as someone who was in university. They were also told that they would be given an incentive of $45 if they managed to fool the examiner.

The self-report measures did not distinguish between those diagnosed with ADHD and the feigners at all, though the controls scored lower than both these groups. This suggested that those with ADHD and those asked to feign were reporting similar levels of ADHD symptoms.

The neuropsychological tests (which included a test of reading skills, the Stroop color and word test, a test of recalling a list of words, and a task called the CPT where you press a spacebar or some such key to any letter except an X when they appear on the screen) proved more interesting. Generally speaking, the feigners responded in such a way that they showed the greatest level of impairment on most tests compared to both the controls and the ADHD-ers -- in other words, the feigners tended to overdo it. The latter two groups, however, generally did not differ from each other statistically, though the ADHD-ers did numerically worse than the controls. Basically, the tests were picking up moderately well on feigners, but not those with ADHD.

On an aside, having administered quite a few of these neuropsych tests to patients myself, I can personally attest to the fact that some of these tests are mind-numbingly boring and are as much an assessment of ADHD for the examiner as they are for the subject.

Anyway, back on topic - last were the SVTs. These pretty much followed the same pattern as the neuropsych tests. Feigners did statistically worse than controls and ADHD-ers, though the latter two groups didn't differ from each other. Interestingly, however, these SVTs were generally not very sensitive to feigning (i.e., identifying people who were feigning as feigning) though their specifity to ADHD was pretty good (identifying people without ADHD as not having ADHD).

Anyway, to sum it all up, pretty much none of the measures used in this study did a good job of differentiating those with and without ADHD, apart from the self-report ones and those are pretty easy to fake anyways. The neuropsych tests did an OK job on picking up on the feigners or those asked to fake ADHD since they did overdo it on quite a few of the tests, but since these are already general measures for these (e.g., some of the SVTs used in the study), it doesn't seem very useful to use ADHD-specific measures like the CPT for this purpose (which seemed to have functioned pretty crappily in this study anyway).

Now, this study did use a college population, so presumably, the really impaired folks with ADHD were not a part of the study. However, as the authors note, since a lot of assessments are done on college kids (and younger kids in school), if the neuropsych tests don't pick up on these problems in these less impaired populations, what is the point of administering these tests to detect ADHD in the first place?

More importantly, an issue that the authors skirt around in the discussion is that there seems to be no sign really that there is anything specific to the ADHD diagnosis in their study. However, that is a pretty bold statement to make, and their study is on the smaller side. I probably wouldn't have made it either if I were writing up the study. But, results like these make you wonder what it means to have ADHD, and whether it deserves a diagnostic status as a disorder in its own right. Things like difficulties with attention and impulsivity are nonspecific symptoms that are implicated in a whole lot of other disorders like depression, substance problems, schizophrenia, borderline personality disorder, and so on. It's kinda like trying to diagnose which medical disorder somone has from knowing that they have fever. Without knowing other symptoms, one would be hard pressed to figure out whether the fever is part of a flu, meningitis, hepatitis, or leukemia, and how to treat it, no?

Sollman, M., Ranseen, J., & Berry, D. (2010). Detection of feigned ADHD in college  students. Psychological Assessment, 22 (2), 325-335 DOI: 10.1037/a0018857

Sunday, May 1, 2011

Talented Lingo Kid (Ravi)

A friend sent me the links to the following series of youtube videos on a street kid (Ravi) in India who sells peacock feather fans to tourists for a living. His ability to speak in different languages is simply phenomenal! This kid doesn't even go to school and simply picks up languages from talking to tourists.

In the two videos below, the person who uploaded these videos filmed Ravi over over a couple of different years (once in 2007, and once in 2009) displaying his skill with various languagues.

In this next video, we some more information on Ravi's background, his family, where he lives, and so on.

I was really wowed by these videos. It makes you wonder what other brainpower, skill, and potential like this exists in developing countries that simply lies untapped and is not even given a chance, while academic researchers like us get funded tens of thousands of dollars for publishing esoteric research articles that make little difference to science or humanity in any way.

Sunday, April 24, 2011

Guess That Psychiatric Disorder

Here’s a question for you psychiatrists and clinical psychologists out there. What disorder is characterized by the following symptoms:
  1. Congenital onset
  2. Dwarfism
  3. Emotional lability and immaturity
  4. Knowledge deficits
  5. Legume anorexia
National surveys over the past 20 years have shown that this condition is present in approximately a quarter of the US population at any given time.

Still stumped?

The name of this “debilitating disorder” is…..wait for it…..CHILDHOOD! are the one with the issues - you are wearing only one sock!

I took the above snippet on criteria for childhood from an entertaining article by Jordan Smoller (who is currently an Associate Professor of Psychiatry at Harvard Medical School). It’s an oldie but a goodie – it was published in 1985. I have pasted the entire thing below for your benefit and I highly recommend reading it. It’s pretty short, an easy read, and very entertaining (be sure to pay attention to the references!). Any article that has sentences like these:

“Folk wisdom is supported by empirical observation -- children will rarely eat their vegetables (see Popeye, 1957, for review).”  and

“Impressive evidence of a genetic component of childhood comes from a large-scale twin study by Brady and Partridge (1972)….Among identical or monozygotic twins, concordance was unusually high (0.92), i.e., when one twin was diagnosed with childhood, the other twin was almost always a child as well.”

is a winner in my book.

In fact, I think we need an update to Smoller’s article since it’s about 25 years old. So here's psychbytes' addendum to Smoller's article.

"Given the current focus on neurobiology, molecular genetics, and statistical modeling, we need to clearly consider these criteria while defining “childhood” as well. It’s well known that childhood is associated with extensive “brain volume abnormalities” and “decreased functional connectivity” compared to adulthood. However, as with any other psychiatric disorder, we have few genes that have been associated with it, though statistical models show that childhood “runs in families” and that without a doubt, it has a “strong, genetic component”. Let’s also not forget that key features of childhood, such as height, weight, and age, show very few (if any) discontinuities with “adulthood”. Thus, if one were to fit latent variable models to such variables assessed in childhood, we would see that these are dimensional in nature, and thus the categorical concept of childhood is statistically untenable. Also, note that childhood is “comorbid” with several other mental and physical disorders. Perhaps, on the basis of this, as the DSM-5 leadership has advocated, maybe we need to eradicate the category of childhood, and evaluate it as a “cross-cutting dimension” in future versions of the DSM?"

Now, clearly, all of this is meant to be satirical. But, humor aside, I think it gets at the heart of the definition of a mental disorder, and shows how scientific language can make almost anything sound abnormal or weird. It reminded me of the Nacirema series of articles in anthropology (which I also recommend reading). It also speaks to how defining a mental disorder solely on the basis of arbitrary criteria (see DSM 5 proposal for definition of mental disorder) such as “impairment”, “psychobiological dysfunction”, and “behavioral or psychological syndromes or patterns” is problematic.

Don’t get me wrong – I am a researcher in psychology and neuroscience and I do think we need some sort of criteria to be set out for a mental disorder. I do believe things like schizophrenia and depression are disorders, and that childhood isn’t. But having read over this article and others like it, I am hard pressed to come up with a reason as to why I believe that.  

Smoller’s article below:

- Jordan W. Smoller, University of Pennsylvania

Childhood is a syndrome which has only recently begun to receive serious attention from clinicians. The syndrome itself, however, is not at all recent. As early as the 8th century, the Persian historian Kidnom made references to "short, noisy creatures," who may well have been what we now call "children." The treatment of children, however, was unknown until this century, when so-called "child psychologists" and "child psychiatrists" became common. Despite this history of clinical neglect, it has been estimated that well over half of all Americans alive today have experienced childhood directly (Seuss, 1983). In fact, the actual numbers are probably much higher, since these data are based on self-reports which may be subject to social desirability biases and retrospective distortion. The growing acceptance of childhood as a distinct phenomenon is reflected in the proposed inclusion of the syndrome in the upcoming Diagnostic and Statistical Manual of Mental Disorders, 4th edition, or DSM-IV, of the American Psychiatric Association (1990). Clinicians are still in disagreement about the significant clinical features of childhood, but the proposed DSM-IV will almost certainly include the following core features:

1. Congenital onset
2. Dwarfism
3. Emotional lability and immaturity
4. Knowledge deficits
5. Legume anorexia

Clinical Features of Childhood

Although the focus of this paper is on the efficacy of conventional treatment of childhood, the five clinical markers mentioned above merit further discussion for those unfamiliar with this patient population.


In one of the few existing literature reviews on childhood, Temple- Black (1982) has noted that childhood is almost always present at birth, although it may go undetected for years or even remain subclinical indefinitely. This observation has led some investigators to speculate on a biological contribution to childhood. As one psychologist has put it, "we may soon be in a position to distinguish organic childhood from functional childhood" (Rogers, 1979).


This is certainly the most familiar marker of childhood. It is widely known that children are physically short relative to the population at large. Indeed, common clinical wisdom suggests that the treatment of the so-called "small child" (or "tot") is particularly difficult. These children are known to exhibit infantile behavior and display a startling lack of insight (Tom and Jerry, 1967).


This aspect of childhood is often the only basis for a clinician's diagnosis. As a result, many otherwise normal adults are misdiagnosed as children and must suffer the unnecessary social stigma of being labeled a "child" by professionals and friends alike.


While many children have IQ's with or even above the norm, almost all will manifest knowledge deficits. Anyone who has known a real child has experienced the frustration of trying to discuss any topic that requires some general knowledge. Children seem to have little knowledge about the world they live in. Politics, art, and science -- children are largely ignorant of these. Perhaps it is because of this ignorance, but the sad fact is that most children have few friends who are not, themselves, children.


This last identifying feature is perhaps the most unexpected. Folk wisdom is supported by empirical observation -- children will rarely eat their vegetables (see Popeye, 1957, for review).

Causes of Childhood

Now that we know what it is, what can we say about the causes of childhood? Recent years have seen a flurry of theory and speculation from a number of perspectives. Some of the most prominent are reviewed below.

Sociological Model

Emile Durkind was perhaps the first to speculate about sociological causes of childhood. He points out two key observations about children: 1) the vast majority of children are unemployed, and 2) children represent one of the least educated segments of our society. In fact, it has been estimated that less than 20% of children have had more than fourth grade education. Clearly, children are an "out-group." Because of their intellectual handicap, children are even denied the right to vote. From the sociologist's perspective, treatment should be aimed at helping assimilate children into mainstream society. Unfortunately, some victims are so incapacitated by their childhood that they are simply not competent to work. One promising rehabilitation program (Spanky and Alfalfa, 1978) has trained victims of severe childhood to sell lemonade.

Biological Model

The observation that childhood is usually present from birth has led some to speculate on a biological contribution. An early investigation by Flintstone and Jetson (1939) indicated that childhood runs in families. Their survey of over 8,000 American families revealed that over half contained more than one child. Further investigation revealed that even most non-child family members had experienced childhood at some point. Cross-cultural studies (e.g., Mowgli & Din, 1950) indicate that family childhood is even more prevalent in the Far East. For example, in Indian and Chinese families, as many as three out of four family members may have childhood. Impressive evidence of a genetic component of childhood comes from a large-scale twin study by Brady and Partridge (1972). These authors studied over 106 pairs of twins, looking at concordance rates for childhood. Among identical or monozygotic twins, concordance was unusually high (0.92), i.e., when one twin was diagnosed with childhood, the other twin was almost always a child as well.

Psychological Models

A considerable number of psychologically-based theories of the development of childhood exist. They are too numerous to review here. Among the more familiar models are Seligman's "learned childishness" model. According to this model, individuals who are treated like children eventually give up and become children. As a counterpoint to such theories, some experts have claimed that childhood does not really exist. Szasz (1980) has called "childhood" an expedient label. In seeking conformity, we handicap those whom we find unruly or too short to deal with by labelling them "children."

Treatment of Childhood

Efforts to treat childhood are as old as the syndrome itself. Only in modern times, however, have humane and systematic treatment protocols been applied. In part, this increased attention to the problem may be due to the sheer number of individuals suffering from childhood. Government statistics (DHHS) reveal that there are more children alive today than at any time in our history. To paraphrase P.T. Barnum: "There's a child born every minute." The overwhelming number of children has made government intervention inevitable. The nineteenth century saw the institution of what remains the largest single program for the treatment of childhood -- so-called "public schools." Under this colossal program, individuals are placed into treatment groups based on the severity of their condition. For example, those most severely afflicted may be placed in a "kindergarten" program. Patients at this level are typically short, unruly, emotionally immature, and intellectually deficient. Given this type of individual, therapy is essentially one of patient management and of helping the child master basic skills (e.g., finger-painting). Unfortunately, the "school" system has been largely ineffective. Not only is the program a massive tax burden, but it has failed even to slow down the rising incidence of childhood. Faced with this failure and the growing epidemic of childhood, mental health professionals are devoting increasing attention to the treatment of childhood. Given a theoretical framework by Freud's landmark treatises on childhood, child psychiatrists and psychologists claimed great successes in their clinical interventions. By the 1950's, however, the clinicians' optimism had waned. Even after years of costly analysis, many victims remained children. The following case (taken from Gumbie & Poke, 1957) is typical.

Billy J., age 8, was brought to treatment by his parents. Billy's affliction was painfully obvious. He stood only 4'3" high and weighed a scant 70 lbs., despite the fact that he ate voraciously. Billy presented a variety of troubling symptoms. His voice was noticeably high for a man. He displayed legume anorexia, and, according to his parents, often refused to bathe. His intellectual functioning was also below normal -- he had little general knowledge and could barely write a structured sentence. Social skills were also deficient. He often spoke inappropriately and exhibited "whining behaviour." His sexual experience was non-existent. Indeed, Billy considered women "icky." His parents reported that his condition had been present from birth, improving gradually after he was placed in a school at age 5. The diagnosis was "primary childhood." After years of painstaking treatment, Billy improved gradually. At age 11, his height and weight have increased, his social skills are broader, and he is now functional enough to hold down a "paper route."

After years of this kind of frustration, startling new evidence has come to light which suggests that the prognosis in cases of childhood may not be all gloom. A critical review by Fudd (1972) noted that studies of the childhood syndrome tend to lack careful follow-up. Acting on this observation, Moe, Larrie, and Kirly (1974) began a large-scale longitudinal study.

These investigators studied two groups. The first group consisted of 34 children currently engaged in a long-term conventional treatment program. The second was a group of 42 children receiving no treatment. All subjects had been diagnosed as children at least 4 years previously, with a mean duration of childhood of 6.4 years. At the end of one year, the results confirmed the clinical wisdom that childhood is a refractory disorder -- virtually all symptoms persisted and the treatment group was only slightly better off than the controls. The results, however, of a careful 10-year follow-up were startling. The investigators (Moe, Larrie, Kirly , & Shemp, 1984) assessed the original cohort on a variety of measures. General knowledge and emotional maturity were assessed with standard measures. Height was assessed by the "metric system" (see Ruler, 1923), and legume appetite by the Vegetable Appetite Test (VAT) designed by Popeye (1968). Moe et al. found that subjects improved uniformly on all measures. Indeed, in most cases, the subjects appeared to be symptom-free. Moe et al. report a spontaneous remission rate of 95%, a finding which is certain to revolutionize the clinical approach to childhood. These recent results suggests that the prognosis for victims of childhood may not be so bad as we have feared. We must not, however, become too complacent. Despite its apparently high spontaneous remission rate, childhood remains one of the most serious and rapidly growing disorders facing mental health professional today. And, beyond the psychological pain it brings, childhood has recently been linked to a number of physical disorders. Twenty years ago, Howdi, Doodi, and Beauzeau (1965) demonstrated a six-fold increased risk of chicken pox, measles, and mumps among children as compared with normal controls. Later, Barby and Kenn (1971) linked childhood to an elevated risk of accidents -- compared with normal adults, victims of childhood were much more likely to scrape their knees, lose their teeth, and fall off their bikes. Clearly, much more research is needed before we can give any real hope to the millions of victims wracked by this insidious disorder.


American Psychiatric Association (1990). The diagnostic and statistical manual of mental disorders, 4th edition: A preliminary report. Washington, D.C.; APA.

Barby, B., & Kenn, K. (1971). The plasticity of behaviour. In B. Barby & K. Kenn (Eds.), Psychotherapies R Us. Detroit: Ronco Press.

Brady, C., & Partridge, S. (1972). My dads bigger than your dad. Acta Eur. Age, 9, 123-126.

Flintstone, F., & Jetson, G. (1939). Cognitive mediation of labour disputes. Industrial Psychology Today, 2, 23-35.

Fudd, E.J. (1972). Locus of control and shoe-size. Journal of Footwear Psychology, 78, 345-356.

Gumbie, G., & Pokey, P. (1957). A cognitive theory of iron-smelting. Journal of Abnormal Metallurgy, 45, 235-239.

Howdi, C., Doodi, C., & Beauzeau, C. (1965). Western civilization: A review of the literature. Reader's Digest, 60, 23-25.

Moe, R., Larrie, T., & Kirly, Q. (1974). State childhood vs. trait childhood. TV guide, May 12-19, 1-3.

Moe, R., Larrie, T., Kirly, Q., & Shemp, C. (1984). Spontaneous remission of childhood In W.C. Fields (Ed.), New hope for children and animals. Hollywood: Acme Press.

Popeye, T.S.M. (1957). The use of spinach in extreme circumstances. Journal of Vegetable Science, 58, 530-538.

Popeye, T.S.M. (1968). Spinach: A phenomenological perspective. Existential Botany, 35, 908-813.

Rogers, F. (1979). Becoming my neighbour. New York: Soft Press.

Ruler, Y. (1923). Assessing measurements protocols by the multi-method multiple regression index for the psychometric analysis of factorial interaction. Annals of Boredom, 67, 1190-1260.

Spanky, D., & Alfalfa, Q. (1978). Coping with puberty. Sears Catalogue, 45-46.

Seuss, D.R. (1983). A psychometric analysis of green eggs with and without ham. Journal of Clinical Cuisine, 245, 567-578.

Temple-Black, S. (1982). Childhood: an ever-so sad disorder. Journal of Precocity, 3, 129-134.

Tom, C., & Jerry, M. (1967). Human behaviour as a model for understanding the rat. In M. de Sade (Ed.). The Rewards of Punishment. Paris: Bench Press.

Further Readings

Christ, J.H. (1980). Grandiosity in children. Journal of applied theology, 1, 1-1000.

Joe, G.I. (1965). Aggressive fantasy as wish fulfilment. Archives of General MacArthur, 5, 23-45.

Leary, T. (1969). Pharmacotherapy for childhood. Annals of astrological Science, 67, 456-459.

Kissoff, K.G.B. (1975). Extinction of learnt behaviour. Paper presented to the Siberian Psychological Association, 38th annual Annual meeting, Kamchatka.

Smythe, C., & Barnes, T. (1979). Behaviour therapy prevents tooth decay. Journal of Behavioral Orthodontics, 5, 79-89.

Potash, S., & Hoser, B. (1980). A failure to replicate the results of Smythe and Barnes. Journal of Dental Psychiatry, 34, 678-680.

Smythe, C., & Barnes, T. (1980). Your study was poorly done: A reply to Potash and Hoser. Annual review of Aquatic Psychiatry, 10, 123-156.

Potash, S., & Hoser, B. (1981). Your mother wears army boots: A further reply to Smythe and Barnes. Archives of Invective Research, 56, 5-9.

Smythe, C., & Barnes, T. (1982). Embarrassing moments in the sex lives of Potash and Hoser: A further reply. National Enquirer, May 16.

Jordan W. Smoller (1985). The etiology and treatment of childhood Journal of Polymorphous Perversity, 2 (2), 3-7

Friday, April 15, 2011

To pee or not to pee - that is the question

And the answer would be not…especially if you have a decision to make.

On a somewhat related note, don't try doing any of the above X'ed out actions in Japan either, which is where this picture was taken.

Here's a recent amusing study that examined whether “urination urgency” (yep, you read that right – in other words, how badly you needed to pee) spilled over to “inhibitory control” in other domains. The authors did a set of four studies where they asked subjects to drink a lot of water and checked out how this affected their performance on a Stroop task and on what they called intertemporal patience (also known as “delay discounting” – i.e., choice between small reward now vs. large reward later).

In the first study, which involved the Stroop task, subjects were asked to indicate the meaning (dominant response) or color (non-dominant; requires “inhibiting” the tendency to read) of the word on screen. Interestingly, subjects who had to go were able to name the color of the word quicker, while urination urgency had no impact on time taken to indicate meaning of the word.

In study 2, they had participants drink different amounts of water (700 ml vs 50 ml – high vs. low bladder pressure conditions) and then after about a 45 minute delay to ensure adequate levels of pressure and urgency, they had participants do a delay discounting task with different levels of money (e.g., 16 euros the next day or 30 euros in 35 days). Again, interestingly, participants who drank more water actually chose the delayed reward more often. I would have totally predicted the opposite effect!

Anyway, Study 3 did the same manipulation, but tried to relate the choices to a personality measure – the Behavioral Inhibition Scales (BIS). The authors note that “the BIS is sensitive to signals of punishment and is involved in the inhibition of ongoing behavior in the face of a threat”. As expected, they found high BIS scorers were more likely to choose the delayed reward in the high bladder pressure condition. Just as a pedantic aside, the literature on the BIS/BAS scales doesn't provide the strongest support for the theory, and this study doesn't fit in well with the entertaining tone of the rest of the article, but I figured I would add a paragraph on it for the sake of scientific integrity.

But never fear, dear reader. This does not mean that you have to drink a gallon of water the next time you are trying to decide between two competing choices. Wisely, in study 4, the authors decided to see if merely viewing words associated with peeing (e.g., “urination,” “toilet,” “bladder” vs. words such as “table,” “watching,” “hammer”) could lead to similar effects. And sure enough, it did! According to the authors, such "exogenous cues" were potent enough to evoke similar effects in their participants.

So there you go – now you hold to key to making wise, patient, choices in life! Just visualize your toilet the next time.....

Tuk MA, Trampe D, & Warlop L (2011). Inhibitory Spillover: Increased Urination Urgency Facilitates Impulse Control in Unrelated Domains. Psychological science : a journal of the American Psychological Society / APS PMID: 21467548

Saturday, April 9, 2011

The politics of the DSM 5 personality disorders

Most science blog posts post a link to an academic article or two and discuss their merits or lack thereof. I am going to do something slightly different - I am linking to an entire special issue of a journal, with pdfs freely available online - and recommend that you do NOT waste any time reading any of it. All it really shows is a bunch of academics bickering over stuff that doesn't seem to make much of a difference.

I imagine the DSM 5 PD workgroup meetings look something like this:

South Korean politicians fighting

Anyway, on to the articles. Out of all the changes being considered for the DSM 5, the personality disorder (PD) work group has proposed some of the most sweeping ones such as dropping 5 of the current PDs entirely and adding a dimensional component that somehow involved asssessing 6 trait domains and 37 facets  for the remaining PDs. Not surprisingly, this has not gone over too well.

The Journal of Personality Disorders has recently published a special issue (see link here with pdfs) that has invited articles by the DSM PD workgroup members and other commentaries in response to it. I repeat - don't bother reading any of it. Most of these articles are filled with jargon (SNAP, DAPP, NEO, DIPSI, HEXACO, OMGWTFBBQ), are quite boring, appear to be selective in whatever literature they cite, with quite a few of the authors increasing their self-citation count, while sniping at each other. Here's a brief rundown.

In the first article, the workgroup (Andrew Skodol et al.) rehash their proposal, but note that "Feedback from the [DSM-5] website posting suggested that this system was too complicated, redundant with the full clinicians’ trait ratings, and unwieldy". Really? Nah! Say it ain't so! So their solution is to separate the 5 PD "types", from the "traits" and "facets" in the field trials, and somehow refine this system. How? It is not entirely clear.

In the next article (Krueger et al.), the authors repeatedly talk about the "empirical structure of personality". Curiously, while there is some overlap in authors with the first one, they are not all identical. I suspect this means some sort of division among the PD workgroup members. Anyway, as the authors themselves acknowledge, the bulk of the evidence for their proposal uses a statistical technique called factor analysis, which is essentially based on a whole lot of correlations. Why this makes the authors' proposal or review any more "empirical" is pretty unclear to me. The authors also take some effort to delineate why Thomas Widiger's (another big name in the personality world) preferred model of personality may not be as "empirical" as theirs.

The remaining articles are commentaries. Clarkin and Huprich's, and Zimmerman's, are worth skimming over, but don't really say anything that wasn't already known - i.e., the PD proposal is too complex to be clinically useful, and not really based on much evidence. Then, we have an article by the aforementioned Widiger, who hits back pretty hard at Lee Anna Clark and Robert Krueger (two other big names) for not using his preferred model of personality, and spends 13 pages or so picking apart the PD proposal and Clark and Krueger's work.

This is followed by a couple of articles by Robert Bornstein (an expert on Dependent PD) and Elsa Ronningstam (an expert on Narcissistic PD). These two PDs are slated to be dropped. So, no prizes for guessing what these commentaries are about. And lastly, Joel Paris has an article on the use of endophenotypes for diagnosing PDs - though as he clearly notes, we don't have any yet (which DSM disorder does anyway?). In other words, an academic exercise in what might be useful if we ever find it.

While I occasionally use some personality inventories in my work, most of my work doesn't involve the PDs, and as such, I have no strong ties to a 5-, 6-, or 18-factor model of personality. I picked up this special issue hoping for some sort of enlightenment on the PD proposal. Now, instead, I wish I could get back the hours I spent reading these articles.

Skodol AE, Bender DS, Morey LC, Clark LA, Oldham JM, Alarcon RD, Krueger RF, Verheul R, Bell CC, & Siever LJ (2011). Personality Disorder Types Proposed for DSM-5. Journal of personality disorders, 25 (2), 136-69 PMID: 21466247

Krueger RF, Eaton NR, Clark LA, Watson D, Markon KE, Derringer J, Skodol A, & Livesley WJ (2011). Deriving an Empirical Structure of Personality Pathology for DSM-5. Journal of personality disorders, 25 (2), 170-91 PMID: 21466248

Clarkin JF, & Huprich SK (2011). Do DSM-5 Personality Disorder Proposals Meet Criteria for Clinical Utility? Journal of personality disorders, 25 (2), 192-205 PMID: 21466249

Zimmerman M (2011). A Critique of the Proposed Prototype Rating System for Personality Disorders in DSM-5. Journal of personality disorders, 25 (2), 206-21 PMID: 21466250

Widiger TA (2011). The DSM-5 Dimensional Model of Personality Disorder: Rationale and Empirical Support. Journal of personality disorders, 25 (2), 222-34 PMID: 21466251

Bornstein RF (2011). Reconceptualizing Personality Pathology in DSM-5: Limitations in Evidence for Eliminating Dependent Personality Disorder and Other DSM-IV Syndromes. Journal of personality disorders, 25 (2), 235-47 PMID: 21466252

Ronningstam E (2011). Narcissistic Personality Disorder in DSM-V-In Support of Retaining a Significant Diagnosis. Journal of personality disorders, 25 (2), 248-59 PMID: 21466253

Paris J (2011). Endophenotypes and the diagnosis of personality disorders. Journal of personality disorders, 25 (2), 260-8 PMID: 21466254

Monday, April 4, 2011

Scientists like publishing studies that say “ZOMG!! THE BRAIN – IT’S DIFFERENT!!!”

The Archives of General Psychiatry just published a study by John Ioannidis which basically says that for whatever reason, studies that say that brain volumes are different in different psychiatric disorders are more likely to be published. Ioannidis has shown similar meta-research type findings before in other fields already (see this article for example), and I highly doubt anyone is really surprised by this finding. Still, it’s cool to see this issue being acknowledged by a relatively high-profile journal like Archives.

Basically, Ioannidis takes a few meta-analyses that have examined “brain volume abnormalities” in different psychiatric disorders from 2006-2009, calculates the number of comparisons across studies that would be expected to have positive results based on statistical power, and then checks that against the actual number of positive findings reported in those studies. To make a long story short, whether he slices and dices it by disorder or by brain structure, studies were largely biased towards reporting statistically significant findings.

Now what would be really nice is if Archives (and other psychiatry journals) actually did something with this finding instead of continuing to publish articles that are basically just neurobabble.

John Ioannidis (2011). Excess Significance Bias in the Literature on Brain Volume Abnormalities Archives of General Psychiatry

Friday, April 1, 2011

The pouf is mightier than the pen.....

This has GOT to be an April Fool's joke. Apparently, Snooki was paid more than Nobel Prize winning author Toni Morrison to speak at Rutgers University. Snooki's profound advice for students there was : "Study hard, but party harder".

Would someone please confirm this is a joke already?