Lies, damned lies, and statistics

A recent article in the New York Times reported on the link between suicide and depression. Two studies were released in The American Journal of Psychiatry (AJP) that question the findings that show an increased risk for suicide on antidepressants for all age groups. In the first study, psychiatrist Dr. Gregory Simon of Seattle’s Center for Health Studies analyzed the health records of just over 109,000 people who were being treated for depression. Simon found that “suicide attempts were most common in the month before treatment began, declined sharply in the month after it began, and tapered off in the following six months.” Medication therapy, psychotherapy, or a combination of the two continued to support data that “treating depression reduced suicide risk regardless of technique.” However, the issue is whether the medication really DID do an effective job of curbing suicide attempts. Obviously, this study would contradict many of the data presented to the FDA that have found an increased risk for suicide on an antidepressant. Furious Seasons reported on similar findings from different studies early last year.

The second study, led by Dr. Robert Gibbons of the Center for Health Statistics at UIC, gathered data from the Veterans Health Administration of nearly 227,000 veterans suffering from depression. Gibbons discovered that veterans who began antidepressant therapy had a suicide attempt rate one-third that of those who did not receive antid therapy. Researchers also found that “this was true for men 18 to 25 as well as for older adults.”

Given that veterans/those who serve in the armed forces are primarily men, it wouldn’t surprise me if the suicide rate was low to begin with.Women, on the whole, are known for more suicidal attempts. Guys are usually a “one and done” attempt – they use a violent means of suicide, e.g., firearms.

If I haven’t said it in the past, I’ll say it again: I’m not a whiz when it comes to statistics. Feel free to skip all my assumptions and theories and read a knowledgeable editorial by Dr. David Brent on these studies. But I’ll do my best to interpret the data from the first study from my perspective.

A total of 109,256 people participated in the study, which led to a total of 131,788 “treatment episodes.” The control groups are as follows:

  • Meds from a primary care physician (PCP) – 70,368
  • Meds from a psychiatrist – 7,297
  • Psychotherapy only – 54,123

No doubt that some of these individuals underwent both med therapy and psychotherapy.

The demographic breakdown isn’t clear-cut to me. The percentage of females under PCP care was 69%; the percentage of those under 25 was 15%. In my opinion, that’s a small percentage of data for patients under 25 years, but I’m no statistician. The percentage of females under psychiatrist care was 62% while the percentage for those under 25 was 27%. Sixty-nine percent of females comprised the psychotherapy group as well as 21% of patients under age 25. All it sounds like to me is that the majority of the data came from females and those older than
25. If I’m wrong, let me know.

The study followed the suicide attempts of these people 3 months before beginning their respective treatments and 6 months after. Five percent began their treatment with psychiatrists, 55% began their treatment with PCPs, and the remaining 40 underwent psychotherapy. I can only assume that each individual started out on one form of treatment. The study indicates that “patients receiving antidepressant prescriptions from psychiatrists were younger and more often male.”

(I’m writing this late at night so my thought process may not be coherent, but follow me, if you may.) If younger and/or male patients were predominantly the ones to receive antid medications, it would follow that those groups received the most benefit from the medication therapy. However, if my demographic analysis is somewhat correct, then that means the majority of the group – older patients and/or females – did not receive  as much benefit. Then there’s the following, which I’m not sure how to interpret:

“Overall, incidence of suicide attempts during this period was highest among patients receiving antidepressant treatment from a psychiatrist, slightly lower among patients starting psychotherapy, and much lower among patients starting antidepressant treatment in primary care.”

Methinks there’s logic to this data. Patients who receive treatment from a PCP probably suffer from mild-to-moderate depression and are not referred to a psychiatrist. Patients who undergo psychotherapy range from mild to severe depression. Since those undergoing psychotherapy tend to have more suicidal tendencies than those seeing a PCP, the incidence of suicide attempts in this group would be higher. Last but not least, patients seeing psychiatrists had the highest incidence of suicides overall. I think a ton of conclusions can be drawn from that to fit any argument. (For example, “Aha! Antidepressants DO trigger more suicide problems!”) But… that’s not the immediate conclusion I
see here. Psychiatrists deal with the most severe and mentally ill patients of any specialty (PCPs, psychologists, etc.). Psychiatrists’ only job is to treat people with mental illness, the most common being depression. As a result, the influx of depressed patients is significantly higher, which means the incidence of suicide attempts from these patients is higher.

“This and earlier studies found that rates of suicide attempt or suicide death are at least three times as high among patients treated by psychiatrists.”

The NYTimes pointed out something interesting from the Simon study:

The authors acknowledged that they had no way to assess the severity of illness either before or after starting treatment, and that about a third of patients dropped out of treatment within a few weeks, two factors that may have influenced the results.

Hmph, probably. So about a third of the patients dropped out of treatment “within a few weeks,” which gives me no real indication of how far along these patients went. I’m also not sure if there were included in the 100,000
figure or if the total number of people shrank from a higher number. As for not assessing illness, this could mean the
difference between a one-time attempt or multiple attempts. It seems that out of the 100,000 individuals, there were only 715 suicide attempts (97 being considered “possible” attempts as opposed to “definite”). If this is really the case, I’m not sure how the “antidepressants doesn’t cause suicide” link fits here. I would think that there would need to be a larger group of people who have attempted suicide and not just struggled with depression.

But like I said, I’m no statistician and I tried to understand the data to the best of my ability. The main point to take away is that people with suicidal thoughts or attempts need to get some kind of treatment. Below is a table of the data that tracked the nine-month period of the study. I’m going to try to upload a file of the two studies. I hope this works: Simon study and Gibbons study.

Antidepressant-suicide linkComments on the stats are welcome.

1 Comment

  1. November 29, 2007 at 2:27 am

    Antidepressants are useless.They don’t help for overcoming depression.
    This statistic is interesting.

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