Tuesday, February 26, 2008

Antidepressants and Placebo Effect

An excerpt from MindHacks:

Psychologist Irving Kirsch, who led this new research, has conducted several previous studies looking at the effectiveness of SSRI antidepressant drugs and found similar results, although this is the first time that the study has factored in the severity of depression.

This study focused on the drugs fluoxetine (Prozac), venlafaxine (Effexor), nefazodone (Serzone), and paroxetine (Seroxat or Paxil) and used the US Freedom of Information Act to request data on (mainly) negative trials that haven't been published to complement the data set from published trials.

In this new analysis, only in severe depression did these medications show a distinct improvement over placebo, and this, the authors suggest, is because of the reduced placebo effect in the severely depressed, rather than than the fact that the medication has a differential effect in those most affected by mood disorders.

It's important to note that the study didn't show that the drugs had no effect in mild-moderate depression. They were all associated with an improvement in depression, but this was no different from placebo (a powerful effect in itself).

It's also important to note that this finding doesn't apply to all antidepressant drugs, and that it doesn't apply to the use of these four drugs in all situations. They are also commonly prescribed for anxiety disorders which weren't investigated in this study.

Link to full-text of PLoS Medicine paper.
Link to Times write-up.

Monday, February 25, 2008

Obsessive Compulsive Disorder

An excerpt from the NY Times:

If Carole Johnson, a retired school administrator who lives near Sacramento, Calif., happens to have a distressing thought while passing through a doorway, she needs to “clear” the thought by passing through the door twice more, doing it precisely three times.

My own challenge is fighting the urge to return to my parked car and check yet again that the parking brake is secure. If I don’t, how can I be sure my car won’t roll into something — or worse, someone?

...

To many of us with obsessive-compulsive disorder, those pleasures are invisible. We walk into a calm and civilized dining room and see things we won’t be able to control. This feeds directly into one of the unifying themes of the disorder: an often crushing inability to handle the unknown.

“The common thread, I think, has something to do with certainty,” said Dr. Michael Jenike, medical director of the Obsessive Compulsive Disorders Institute at McLean Hospital in Belmont, Mass., which is affiliated with Harvard Medical School. “If you have O.C.D., whatever form, there seems to be some problem with being certain about things — whether they’re safe or whether they’ve been done right.”

If lack of certainty is our common challenge, than warding off uncertainty is our common quest. For some of us battling obsessive-compulsive disorder, that means scrubbing our hands to make sure they’re clean, or checking and re-checking everything around us in the name of safety. For others, the need is to arrange various items in order, or repeat actions in ritualized sequences in vain attempts at removing doubt.

These quirks lead to some serious complications in our lives, especially when we find ourselves in a place that triggers obsessive-compulsive behavior, like a restaurant. Once Ms. Johnson gets past the door, she often needs to try out a few tables, looking for one that feels right, as a frustrated maître d’hôtel looks on.

Personally, I am fine with just about any table, although the wobbly ones can spell big trouble. I have harm obsessions, which means I am plagued by the fear that other people will be hurt by something I do, or don’t do. Seated at a less-than-sturdy table, I conjure images of fellow diners being crushed or otherwise injured should I fail to notify the restaurant’s management. This is called a reporting compulsion in the vernacular of the disorder, and before I learned to fight these urges, many a manager heard from me.

One of them was the woman running a coffee house I frequent. One day while sipping my latte at a fake-marble table I leaned forward, and the far end of the tabletop lifted. This barely moved my coffee cup, but it sent my nerves right through the roof. Before I realized it I was crouched over, my head upside down beneath the table. The only responsible thing to do, I decided, was to ask the woman behind the counter to come over for a look. Her lack of concern only exacerbated my problems.

Forget the tabletop, my friend Matt Solomon tells me; it’s what’s on top of the table, and precisely where, that really matters. Mr. Solomon is a 39-year-old lawyer in Fort Worth with order compulsions. To enjoy a meal he needs to separate the salt and pepper shakers, and, ideally, place a napkin holder or other divider midway between them.

Why? He can no more answer that than Ms. Johnson can tell you why she needs to chew her food in sets of three bites or drink her beverages three sips at a time. Three is her magic number. That is about as refined an explanation as any of us can give for our compulsions, rituals that we understand are entirely illogical.

Some of our other concerns may seem familiar. I imagine most diners, for example, have noticed and perhaps even struggled to remove white detergent spots that can sometimes be seen on silverware. But few, I suspect, have gone to the lengths Jared Kant has to get rid of them. Mr. Kant is a 24-year-old research assistant living outside of Boston who has obsessive fears of contamination. (He first came to my attention when I read a memoir he wrote about living with obsessive-compulsive disorder.) Last year he visited a Chinese restaurant with several friends, one of whom pointed out that their silverware was spotted and seemed dirty. Mr. Kant collected all the utensils at the table and attempted to sterilize them by holding them above a small flame at the center of a pu-pu platter, quickly attracting the attention of their waiter.

...

Help is available, in the form of a therapy called exposure response prevention. As the name suggests, the technique calls for exposing people with obsessive-compulsive disorder to situations that trigger obsessions, then preventing them from acting on them. The therapy addresses low-level anxieties, and works up from there.

With restaurant cleanliness, for example, a therapist might have an client rate his anxiety about challenges ranging from simply touching spotted silverware to eating from a spotted plate. Then the therapist would ask him to face those situations while fighting the compulsion to clean or replace spotted items.

The therapy attempts to alter behavior, but it appears to alter much more than that. Dr. Sanjaya Saxena, the director of a program for obsessive-compulsive disorders at the University of California at San Diego, said that exposure response prevention therapy “certainly is changing the brain at the molecular level — that is, at the level of particular proteins that are expressed and created and on the level of neurotransmitter function.” In that sense, he said, “behavioral therapy is biological therapy.”

Morality and Free Will Arguments

A new study by Kathleen Vohs and Jonathan Schooler investigates whether students exposed to arguments against the existence of free will are more likely to cheat. Here is an excerpt from the BPS blog about this study and below is the link to the article (need to have subscribed access to the journal):
Thirty students answered maths problems on a computer. A feigned technical glitch meant that they had to press the space bar each question to stop the computer from giving the answers away. Crucially, before the test, half the students read a passage from the late Francis Crick's book about consciousness, in which he argues that free will is an illusion. These students pressed the space bar less often than the students who hadn't read about free will - in other words, they cheated more.

In a second experiment, dozens of students were exposed to either pro free will, anti free will or neutral statements prior to performing a series of mental tests. Afterwards, the students were allowed to score their own answers, shred them for anonymity, and then award themselves a dollar for each correct answer. The students previously exposed to anti free will messages awarded themselves significantly more money than the other students, probably because they cheated more. It's unlikely they had truly performed better. Two further groups of students, one of which was also exposed to anti free will statements, had their answers marked by the researchers and neither of them performed as well as the first group of anti free will students claimed to have done.

These findings complement survey research showing that people's sense of how much control they have over their own lives is diminishing, as well as data from academia showing that cheating is on the increase. "If exposure to deterministic messages increases the likelihood of unethical actions", the researchers said, "then identifying approaches for insulating the public against this danger becomes imperative."

Vohs, K.D. & Schooler, J.W. (2008). The value of believing in free will. Encouraging a belief in determinism increases cheating. Psychological Science, 19, 49-54.

Thursday, February 21, 2008

Implicit Association Test (IAT)

An excerpt from Mindhacks:

Edge has a video interview with two of its creators, psychologists Mahzarin Banaji and Anthony Greenwald, and an online version of the IAT which allows you to test your unconscious associations in relation to the US presidential candidates.

The IAT is a computer task that measures the strength of automatic, implicit or unconscious associations between concepts.

Let's say we're interested in whether black or white faces are more linked to positive or negative associations.

Faces of black or white people, and either pleasant or unpleasant words are flashed up on screen, one at a time. Participants are asked to press one key if the face is black or the word is pleasant, and other if the face is white or the word is unpleasant.

In other words, you're asked to classify both black faces and pleasant words using the same response, and white faces and unpleasant words using the same response.

Next, you're asked to do the same thing, but with the reverse associations: so you're asked to classify black faces and unpleasant words together, and white faces and pleasant words together.

The idea is that you're going to be quicker doing whichever classification best matches associations you already have.

So, if you already have unconscious associations between white and pleasant, and black and unpleasant, you're going to be quicker when these two responses are grouped.

Importantly, the idea is that these associations are different from our conscious attitudes. Someone who is definitely not racist might still have negative associations with black people, perhaps because of exposure to social stereotypes.

Most studies have more than just the two conditions, to control for order, practice and other effects and if you're interested, you can take part in this exact experiment online.

It was originally thought that the test could uncover people's implicit or hidden attitudes (indeed, it was originally called the Implicit Attitude Test) but it's now generally thought of just in terms of associations, because, in effect, it measures how closely two things are linked, and implicit attitude sounds more like a sort of evaluation or stance on something.

The value in this sort of test is not only in that it can pick out associations we might have but don't admit to or aren't aware of, but it can also map out how various things influence the unconscious structure of meanings in the mind and brain.

Needless to say, it's been researched intensively since it was first uncovered, with research suggesting it can even pick up on hidden violent associations in psychopathic murderers.

Link to video interview and presidential IAT at Edge.
Link to previous WashPost article on the IAT.

Friday, February 15, 2008

Diagnostic Status of PTSD

An excerpt from Mindhacks:

He's made his case in an editorial for the British Journal of Psychiatry and debates his ideas in an engaging discussion in a BJP podcast.

PTSD is the only psychiatric diagnosis where a clear cause forms part of the diagnosis. The person must have experienced a life-threatening event to themself or others, and must have experienced intense fear, helplessness, or horror at the time.

If this is followed by intrusive memories of the event, increased arousal (feeling 'on edge'), avoidance of any reminders and these are long-lasting and they interfere with everyday life, the disorder can be diagnosed.

The trouble is, all of these can be found in people who have not experienced classical 'trauma'. Some people, including Rosen, are arguing that many of the normal reactions to negative events are now being described in terms of mental illness and the concept of PTSD is becoming meaningless:

Peer-reviewed articles have even discussed the possibility of developing PTSD from watching traumatic events on television. It has been suggested that rude comments heard in the workplace can lead to PTSD because a victim might worry about future boundary transgressions: the conceptual equivalent of pre-traumatic stress disorder. New diagnostic categories modeled on PTSD have been proposed, including prolonged duress stress disorder, post-traumatic grief disorder, post-traumatic relationship syndrome, post-traumatic dental care anxiety, and post-traumatic abortion syndrome. Most recently, a new disorder appeared in the professional literature to diagnose individuals impaired by insulting or humiliating events – post-traumatic embitterment disorder. Even expected and understandable reactions after extreme events, such as anxiety and anger, are now referred to as 'symptoms'.

This does not mean that anyone who becomes disturbed after a negative experience shouldn't be helped, just that PTSD is not a useful way of guiding the treatment. Critics argue that the existing categories of depression and anxiety are more than adequate.

In the podcast, Rosen discusses the possibility that PTSD may be 'popular' as a diagnosis because it's perfectly suited to the legal system.

It defines a cause and an effect, a compensation lawyer's dream. This is more important for the American health care system where mental health treatment is often only reimbursed by the insurance companies if a doctor can make a diagnosis.

PTSD might be the only way for a doctor to get insurance companies to pay for treating someone who is having difficulty adjusting to a bad experience.

Interestingly, the diagnosis of PTSD was largely accepted into the diagnostic manuals due to pressure from campaigners wanting the US government to treat Vietnam veterans' mental health needs on their return from the conflict.

A recent study checked the service records of Vietnam veterans who were being treated for PTSD and found only 41% had been exposed to combat, despite their being no difference in the symptoms between 'combat' and 'no combat' troops.

This isn't to suggest that some veterans were 'faking', just that there isn't always a clear connection between a traumatic event and the symptoms of PTSD.

Tuesday, February 12, 2008

Acceptance

An excerpt from the BPS Blog:
according to Jenny McMullen and colleagues who tested the ability of student partiThat's cipants to cope with unpleasant electric shocks of increasing duration. The students were tested before and after receiving tuition in distraction or acceptance techniques.

To learn distraction, the students were asked to imagine how the first round of electric shocks had felt and to distract themselves from these feelings by imagining a pleasant scene. They were also asked to imagine that continuing with the electric shocks in the next part of the experiment was akin to crossing a swamp, and that the best way to get across was to think of pleasant images.

By contrast, the students taught acceptance were told to walk around the room, repeating to themselves 'I cannot walk'. The idea was to teach them that there is a disconnect between what they say to themselves - their thoughts - and what they actually do; that it is possible to continue enduring pain despite the thought that it is getting more uncomfortable. These students were also told to imagine the swamp metaphor, but in their version, the best way to get across was just to notice any unpleasant thoughts and feelings and carry them with them.

Only the distraction training was effective. In the second round of testing, the students taught acceptance were able to endure more electric shocks than they had in the first part of the experiment, but crucially, no such difference was observed for the students taught distraction.

Moreover, other students taught distraction or acceptance based only on very brief instruction, without use of metaphor or exercises, also showed no greater capacity to endure shocks.

MCMULLEN, J., BARNESHOLMES, D., BARNESHOLMES, Y., STEWART, I., LUCIANO, C., COCHRANE, A. (2008). Acceptance versus distraction: Brief instructions, metaphors and exercises in increasing tolerance for self-delivered electric shocks. Behaviour Research and Therapy, 46(1), 122-129. DOI: 10.1016/j.brat.2007.09.002