Stat Counter

Sunday, August 22, 2010

Grad school, Irish style.

Taking some time off from my placebo series, I'd like to talk about my experience as a Phd student in Ireland.

This is somewhat inspired by the zomg grad school blog carnival, but i was too busy to submit in time.

Its also inspired by the fact that everyone who submitted to that carnival was a natural scientist, which impels me to give the social science side of the equation.

First, a few notes on Irish phd's versus the american grad school experience.
First off, there is very little funding, Ireland is in a depression at the moment, and never really put much money into the social sciences before that.
Secondly, what funding there is (in my area at least) tends to be awarded to the student rather than to a PI. Luckily enough, i did get funding (although it doesnt cover conferences or expenses, which sucks).

Also, there tends not to be many courses, you are essentially thrown into research, which I prefer but which many people would not find appealing. I sometimes wish that I'd had people to explain methods and stats in a lot of detail to me at the start, but then again, learning that stuff myself has been extremely rewarding.

So, without further ado, here are my top ten tips for surviving a PhD.

1) Do something you like - this is extremely important, as if you don't like your thesis, its unlikely that you will finish on time or that anyone else will care. Liking your Phd also makes it easier to write good grant applications.

2) Try to figure out what you want to do, in some detail, ASAP. This again is critical to finishing on time. Don't worry if your methods or approach changes, just figure out your key question and how you are going to assess it. Then draw up a schedule. You won't stick to it, but it can often be a spur to ensure that you keep working.

3) Work consistently. This was really difficult for me, as I was always a crammer in school and undergrad. However, this will not work for a PhD (if you want to finish on time at least) so get into the habit of doing some work at least 4 days a week. This is very important when you are, like me, an independent scholar without compatriots in a lab somewhere.

4) Read outside your discipline, especially for methods. Often, the methods in your field will be some amalgam of tradition, stupidity and lack of thought. Other disciplines can often point out the blind spots of your own.

5) Read, read, read. Spend at least six months reading before you start collecting data. Make sure you read around any instrument you plan on using. This can often give you a good idea of unanswered questions, which can help you get published (which is important if you want to stay in academia).

6) In total contrast to the last point, start collecting and analysing data ASAP. There's nothing like trying to figure out your own data to help you to understand the methods you are using. If something doesn't make sense, google it and read some papers. Its likely that someone else has had the same problems, and they may know how to solve it. If you cant collect data quickly for some reason, search the internet and start analysing other peoples data for practice.

7) Use R - seriously, if you intend to do any kind of hardcore statistical analysis, use R. Its the best stats program out there, and is constantly having new packages added. Its made me a much better scientist, both by forcing me to learn exactly what i'm doing (to decipher the error messages) and by centralising all of the routines i need in one place. Most psychologists end up using SPSS, some IRT program, some SEM program and various other odds and ends. R does all of this, so just learn it now before you get left behind.

8) Take some time off. I've lost count of the amount of times I've been stumped on a problem, have taken a couple or hours or a day off and the solution has come to me while I was relaxing. Creative thought and hard slog do not often co-occur, so make time for both.

9)  Use as many useful computer tools as possibe. Get a computerised reference manager, cos references are annoying. Get a good stats program (Use R). Get a good qualitative analysis program (I'm using Nvivo, but theres probably a good open source alternative). Learn LaTeX, lest you lose a whole chapter to the demons that infest Word.

10) Write, write, write. Its often easier to understand what the problems are once you try to explain yourself. Aim to write a few hundred words a day. Take notes on absolutely everything you read, this will save you time in the long run.

Finally, have fun! Doing research is supposed to be fun, and you can bet your ass that all the greats enjoyed their work. To paraphrase something I heard once: Doing a PhD is like living your life; if you're not enjoying it, neither the life nor the PhD will turn out to be any good.

Sunday, August 8, 2010

Placebos: All you never wanted to know (Part 3a) - Experimental Evidence

Well, here we are again to continue on our tour of research surrounding the knife in Descartes eye, the placebo effect.

I wonder sometimes if mind-body dualism hadn't become so popular, would we have learned to understand the placebo effect long before now?

In any case, Part 3 (Parts 1 and 2) of this series is going to look at experimental evidence surrounding the placebo effect. This section may end getten broken up some more, but we will cross that bridge when we come to it.

An interesting study took place in the heady days of 2006 (Kaptchuk et al 2007) and involved some of the biggest names in the field. The study set out to examine the differential effects of two wholly placebo treatments. They used a sham acupuncture treatment and also the traditional sugar pill. Now, if placebo effects were an illusion, one would not expect to see a difference between these two treatments, but thats not what was seen.

The study was an 8 week randomised controlled trial (sortof, given that there was no active ingredient), and the results showed that the two placebos were mostly the same, except that the pill group showed increased hand grip (which was measured objectively, for those of you who care about such things).

The next study is far more interesting, however. Again its Kaptchuk et al, 2008 this time though. Essentially it was a randomised controlled trial of acupuncture with three groups using patients suffering from Irritable Bowel Syndrome.
The first group was the no treatment control. They came in, they took part, but didnt have any treatment.
The second group was minimal contact group. These people received either real or fake acupuncture, but delivered in a business like fashion, and they didnt spend very much time with each patient.
The third group was enhanced acupuncture which had the therapist come in and talk to them for about half an hour before putting in the needles.

At the six week outcome measure point, 3% of group 1, 20% of group 2 and 37% of group 3 had significant improvement (all differences between the groups significant at the p<0.0001 level). This to me is pretty amazing. If a treatment which doesnt tend to do well in clinical trials (acupuncture) augmented by warm and friendly interaction with another can be this effective, how much more effective would it be with a well validated treatment? Its perhaps sad that doctors are now so focus on diagnosing and dismissing that they are not making much of an effort with their relationship with their patients, and this is having a measureable impact on their healing capacities. Anyway, moving on to some fascinating work by Geers et al. In this study student participants took a pill which purported to increase their anxiety and irritableness. However, Geers added a number of interesting modifications to this study. Again, there were 3 main groups in the study. Group 1 - this drug is active and will increase your irritability Group 2- you may or may not get the active drug Group 3 - you are getting a placebo. Geers also measured optiimism levels at baseline. The major findings were as follows. The participants in the deceptive administration group tended to show more of an effect than those in groups 2 or 3. However, optimism mediated these results as those high in optimism tended not to respond to the nocebo suggestion, while those high in pessimism tended to respond much more to the nocebo suggestion. These interesting finding may explain why optimists tend to have better health outcomes than pessimists. So, the take home message is this: be optimistic about your medical treatments, it just might save your life. I hope to get another post on this experimental evidence section up for all of you sometime in the next few days.

Kaptchuk, T. (2006). Sham device v inert pill: randomised controlled trial of two placebo treatments BMJ, 332 (7538), 391-397 DOI: 10.1136/bmj.38726.603310.55

Kaptchuk, T., Kelley, J., Conboy, L., Davis, R., Kerr, C., Jacobson, E., Kirsch, I., Schyner, R., Nam, B., Nguyen, L., Park, M., Rivers, A., McManus, C., Kokkotou, E., Drossman, D., Goldman, P., & Lembo, A. (2008). Components of placebo effect: randomised controlled trial in patients with irritable bowel syndrome BMJ, 336 (7651), 999-1003 DOI: 10.1136/bmj.39524.439618.25

GEERS, A., HELFER, S., KOSBAB, K., WEILAND, P., & LANDRY, S. (2005). Reconsidering the role of personality in placebo effects: Dispositional optimism, situational expectations, and the placebo response Journal of Psychosomatic Research, 58 (2), 121-127 DOI: 10.1016/j.jpsychores.2004.08.011

Tuesday, August 3, 2010

Placebos: All you never wanted to know (Part 2) - Theories

Welcome back to this, the second post in my review of placebos. Now, to the fodder that makes us scientists, theories about the placebo. This is important as a good theory can both account for our data and predict new data, while also giving us something to falsify, which is apparently how science progresses.

Steve Stewart Williams (all round good guy) reviewed the state of placebo theorising in 2004, and he specified that there are a number of criteria that a successful placebo theory should meet.

1) Account for both objective and subjective placebo effects (that whole obj vs subj dichotomy is very unsatisfying to me, but thats another post)
2) Should also account for nocebo effects (negative placebo effects)
3) Should account for dose reponse rates of placebos (take more fake pills, get a better effect)
4) Should account for differences between different forms of placebo treatments
5) Should account for stronger effects on subjective than objective measures
6) Must account for active placebos producing stronger effects (active placebos are real drugs prescribed in either conditions for which they have no specificity, or in too small a dose to have a biological effect)
7) Must explain placebo effects in healthy people in non clinical settings
8) Must account for the general and local effects observed in placebo analgesia

Thats a tall order, and none of the theories we have can account for all of these items. That may be because the placebo is ill defined, or down to a lack of awareness of key features of the effect (a problem in many young sciences and fields of study).

Drumroll please......
Theory the First: Conditioning. This draws from work with behaviourists and physiologists. Basically, the idea is that when given an active drug, we learn to associate the physiological response with the treatment, and then a fake treatment can activate the same response in our bodies.
The trouble with this theory is that it cannot account for placebo effects as a result of new drugs or substances that a person has not experienced before.
That being said, conditioning by means of an active drug or experimental manipulation is probably the most reliable way of inducing a placebo response in an experimental setting.
Its also worth noting that conditioning can occur to the other stimuli (like a white coat, hospital, doctor etc) present in the environment at the time of the active treatment, so figuring out what we have conditioned someone to can be quite difficult.

Theory the Second: The current 800pound gorilla in the ring, expectancy theory (developed by the inestimable Irving Kirsch) suggests that we have certain cognitions that relate to particular treatments, and that these can activate physiological responses which create placebo effects. Expectancy theory is very good at explaining placebo effects, but it raises the question of how to explain "expectancies". To be precise, Kirsch talks about response expectancies, which he defines as the expectation of a non-volitional response (Kirsch 1985). However, given that much of what Kirsch calls non-volitional can be manipulated by hypnosis and meditation, it creates problems in the definition (but that seems to be quite common in this field. In fairness to Kirsch, he knows this as he has worked with hypnosis for many years also, but its a point that gets missed by many people.

Theory the Third: Michael Hyland's motivational concordance is a new kid on the block, having been put forth recently. This theory suggests that placebos are generated by a ritual which fits the belief system or goals of the person concerned. This theory is basically a sysnthesis of the expectancy and conditioning theories, drawing upon both cognitive and behavioural features for its explanation. I do like this theories focus on the action, as this seems to be the essential part of placebo responses.

Theory the Fourth: Allan and Siegel proposed a signal detection model of the placebo effect some years ago, which is elegant in its simplicity. They suggest that placebos alter response thresholds encouraging false postive signals on the part of patients. In other words, there is no placebo save that people alter their way of responding because they feel like they should be better. Unfortunately, this theory does not fit the data on releases of opioids at specific sites to create analgesia, so it must be discarded.

Theory the Fifth: Motivation. This theory is synonomous with Andrew L. Geers, who has examined it in many different contexts in his own work. He suggests that placebo effects are mediated by the desire to reach a particular goal and demonstrates that priming techniques can enhance placebo effects. This theory is useful as it can account for larger clinical placebo effects than are typically seen in the lab. However, the problem here is that one would expect motivation to be high in patients suffering from chronic pain but they typically do not respond well to placebo treatment. The issue with these patients could be that negative expectancies and conditioning built up from previous experience inhibit the showing of the response, but thats just a hypothesis.

So, what can we make of these theories?
Expectancy definitely seems to exert a large influence. Motivation is also quite important, and conditioning probably aids in the retention of placebo effects over time. I personally like the motivational concordance theory quite a lot, as it seems to suggest why so many people report good results from alternative medicines where the RCT's suggest (but only suggest) that they are indistinguishable from placebos.The optimal path (for now) seems to be to include measures for all the various effects in large scale studies, to examine which of them contribute the most to healing.

P.S. Some anthropologists propose an embodied cognition approach to placebo, but I currently don't know enough about it to talk about it here.

Next on this series, Interesting Experimental Placebo evidence (now with added optimism!).

Stewart-Williams, S. (2004). The Placebo Puzzle: Putting Together the Pieces. Health Psychology, 23 (2), 198-206 DOI: 10.1037/0278-6133.23.2.198