Thursday, May 29, 2008

An Ounce Of Prevention

In medicine, therapeutic interventions tend to fall into one of three classes. Tertiary prevention means doing something to reduce the impact of symptoms in a disease that already exists. Secondary prevention is when you try to catch the disease at an earlier stage, either before symptoms develop or before they become severe. Routine blood pressure checks are an example of secondary prevention because blood pressure measurement catches hypertension (hopefully) before complications like stroke or heart disease develop. Finally, primary prevention is when you do something to keep the disease from starting to begin with. Routine pap smears are a primary preventive measure for cervical cancer---the idea is to catch abnormal cells before they transform into cancer.

So how does this all apply to psychiatry?

It's relevant because, unfortunately, in our specialty right now almost all interventions are tertiary interventions. We see patients after a disease has developed, when they are bothered enough by their symptoms (or their families or employers are bothered enough) to make them seek treatment. By the time they come to treatment they have often already experienced some type of morbidity, either in the form of time lost from work or impaired social functioning, or even impaired physical recovery as in the case of hospitalized medical patients with untreated depression.

There have been some secondary prevention efforts. Every October there is a national depression screening day, when health fairs offer evaluations for clinical depression in addition to other general medical assessments. Internists, family practitioners and other primary care providers are starting to include screening for mental disorders as part of routine health care.

The area where psychiatry is still grossly lacking, mainly because of our still-meager understanding of the basic causes of mental illness, is in primary prevention. Simply put, we just aren't very good yet at preventing psychiatric illness.

We do our best primary prevention when the psychiatric disorder is the result of an identifiable physical cause. We can prevent cognitive impairment and lowered IQ by checking babies for hypothyroidism and children for lead poisoning. You can prevent HIV psychosis by preventing the spread of HIV and keeping the disease under control to delay or prevent dementia. General paresis, or dementia due to advanced untreated syphillis, is pretty much gone now due to the invention of penicillin.

Unfortunately, we still don't know how to prevent schizophrenia or bipolar disorder. We may be about to find a way to prevent clinical depression, at least in some patients. The Associated Press today summarized the findings of an article in this week's issue of JAMA regarding the prophylactic use of an antidepressant in post-stroke patients. One hundred twenty-seven stroke patients were divided into three groups: one treated with escitalopram, one given therapy and one group given a placebo. The escitalopram group was significantly less likely to develop clinical depression over the course of the year following stroke than either of the two control groups.

Now I'm waiting for a study to see if prophylactic antidepressants are useful in other at-risk groups, like heart attack patients, who are also prone to clinical depression in the months following the attack.

It's only one study, but it's a start.
And now : an intrusion from Dinah. I've decided I like putting my comments on the front of the post.

So here's the problem with preventative psychiatry in it's infancy. In the studies above, the issue is one of Risk. I don't know that I'd want to take a medication (with all the risks, side effects, possible adverse reactions, and the question of the unknown longterm or short term effects) for a condition that one is at Risk for. Invariably, some people will be exposed to medications who would never develop the targeted illness. It's a hard sell for me, unless the risk is 100 per cent.

I think we like to think maybe if an illness is caught early in it's course, then it won't get as bad, or at least the symptoms can be treated earlier. This is one rationale for on-going psychotherapy in people who want to be seen between episodes: that therapy may prevent future episodes, may give people tools to prevent relapse, and that the subtle signs of illness may be caught sooner before they become full blown episodes.

Thank you for letting me join in here.


Anonymous said...

I consider my psychotherapy to be both curative and preventative which I think is pretty accurate.

How about an Alzheimer's preventative?

Anonymous said...

Certain types of strokes (those resulting in Broca's aphasia) have a very, very high probability of depression. I think prophylactic antidepressants for that population would probably be extremely beneficial.
-a speech pathologist

Anonymous said...

I'm sort of skeptical. Having worked as a med student as an assistant to some big researcher psychiatrist, they are now pushing more and more to identify the "prodrome" of all kinds of syndromes to try preventive treatment. But it is a sleazy business, pushed heavily by drug companies eager to find yet another indication for the new antipsychotics. I did a training workshop on how to administer the tests to identify the "prodrome" (SIPS, SOPS, etc) - and it was creepy how little things that kids/teenagers say were used to make them "prodromal" for schizophrenia.

Alison Cummins said...

There are levels of risk associated with both an intervention and whatever we're trying to prevent.

Dinah, if you are saying that on principle you would advise pregnant women *not* to take Vitamin K (to prevent spina bifida) or Vitamin D (to possibly lower the risk of schizophrenia) because their child is not 100% certain to develop either of these and there are possible side effects from taking pills... then we disagree. Because the risk assessment has been done for Vitamin K and supports taking pills. Vitamin D seems to be still at the "cool new thing" phase, but the Canadian government does recommend a level of intake that for most of us northern-climate dwellers requires taking pills.

Ok, these are vitamins, but as soon as you get into taking things in pill form there are risks. Meeting your Vitamin C and A requirements from eating lots of leafy greens prevents cancer. Taking the same vitamins in pill form stimulates cancer.

Vaccines have risks, and they are given to completely healthy infants who are not 100% certain to die of measles or pertussis if left unvaccinated. We give them anyway, because the balance between the risks of vaccinating and of not vaccinating favour vaccination. (Unless you are antisocial, in which case they may favour not vaccinating, depending on your community. But that's another discussion.)

Birth control pills have risks and are taken by perfectly healthy women. No, it's not 100% certain that a given sexually active woman will become pregnant if she doesn't use birth control, but it has a very, very high probability (quoting anonymous speech pathologist). Because the health risks associated with pregnancy are higher than the health risks associated with birth control pills, many, many healthy women take the risk of using hormonal birth control when they are not trying to become pregnant.

Anyway, the point is that it's not enough to say that "there are risks." Of course there are risks. The question is, what is the balance of risks?

As someone who has suffered both major depression and side effects from an inappropriate and inappropriately-high dose SSRI, if my doctor wanted me to take an SSRI prophylactically after a stroke I would go with her recommendation. I can't imagine trying to do PT and speech therapy when depressed.

Risk is measurable in at least two dimensions: the actual likelihood of something happening, and the awfulness of it happening.

In the case of an SSRI, I can imagine that the risks of dry mouth and/or tummy trouble approach 100% in the postulated person who has just had a stroke, so we are pretty sure that taking the SSRI will cause some discomfort.

On the other hand, there is also an undefined but still high risk that without the SSRI the person will spend a year in bed wishing they were dead and not participating in PT, OT or speech therapy.

Here we are saying that there is a very high risk of something a little or moderately bad happening, that we need to balance with, say, a moderate risk of something awful happening.

Off the top of my head I think I mght set a threshold of a 30% risk of major depression. Dealing with both major depression and a stroke at the same time would be just awful. Even for just two extra weeks. If I'm doing well, presumably the SSRI could be tapered after a while.

But I think a 100% percent risk of something awful happening is too high a threshold to balance against a 90% risk of something much less awful happening.

Dinah, I know you are saying that you would intervene afterwards, once the person has already spent (two weeks to six months?) suicidal in bed. That way we are only treating those who are actually ill, and because they are the ones who will benefit it is appropriate that they be the ones who assume the risk.

But this could be approached another way: anyone who has real discomfort from the SSRI can stop taking it, because in their case the risk has proved to be unacceptable. Those who take the risk of the SSRI and who find the side effects to be minimal can go ahead and continue taking it because the risk balancing is now even more obviously in favour of prophylaxis.

This all said, I am not in favour of treating all odd teenagers with olanzapine because they might be prodromal for schizophrenia. So there is clearly a line to be drawn. I just don't think it has to be at 100%.

shraddha said...

Great article in JAMA.
I would rather take meds to prevent a disease if possible.Low dose treatment generally causes less adverse effects too.(?)

Midwife with a Knife said...

ac: It's actually folate that prevents spina bifida. :)

We do prescribe birth control pills to certain women at high risk for ovarian cancer, because they lower the risk of developing ovarian cancer later. Something about fewer ovulatory cycles..... although birth control pills tend to have few side effects and are low risk, they aren't no risk, and people can get blood clots, etc. from them, but in certain people, the benefits outweigh the risk.

Most of our preventative strategies (heart disease, neural tube defects, cancer, stroke, etc.) require some sort of knowlege about how risk lesions (such as hypertension, BRCA mutations, etc.) lead to the diseases we're trying to prevent. It seems to me, we have little idea about this in psychiatry. We do know a lot of psychiatric disorders have a certain amount of heritability, but I don't think that that's enough.

Also, the drugs we use to prevent the first episode would have to be pretty benign. Zyprexa, for example, has too large a risk of diabetes for it to be a good preventative measure. Maybe the SSRIs could work in a preventative capacity, because they seem to have a pretty low risk of adverse side effects.

Alison Cummins said...

mwwak: Oh dear, and I should know that. Many years ago I majored in Nutrition, though I haven’t worked in the field since then. I feel stupid now, but thanks.

Anonymous said...

I agree with the 2nd anonymous. Recognizing people (and in this context it usually means kids) who might go on to develop a psychiatric disorder is a process with very poor accuracy. And giving kids long-term psych drugs with only tenuous reasons to do so is questionable at best and at worst, creepy and unethical. It is not at all comparable to something like giving vaccines, where the benefits are substantial and nearly certain.

Anonymous said...

I just did a PubMed search about prodromal schizophrenia in children and came up with all of five citations about this that referenced early treatment. All of them cautioned that the data did not show enough risk/benefit information to support pharmacotherapy as a standard-of-care intervention.

I'd put up a link to the citations if I could figure out how to do that. I did it once, but now I can't remember how.

jcat said...

Sh**t...if I could have had - or still have - a preventative med for MDD....

Goes back to my standard argument; the side-effects, unpleasant though they may be sometimes, are nothing compared to not wanting to die every day for years on end. Fat drugs, esp....

Given the options, I'd be begging any kids I ever have to handle the S/E profiles, rather than go through what me and a whole lot of others have and still do.

The Girl said...

It would be interested to find out the "number needed to treat" and their other statistics with this. They do it with all of the other primary prevention drugs, so why not look at psych meds the same way? :)

Anonymous said...

As one whose LD symptoms have worsened considerably from being on ADS long term, I am horrified that antidepressants are being considered as prophylactic treatment for stroke victims who may (the key word) develop depression.

Interestingly, in the same study in which Lexapro was studied for use as a prophylactic treatment, they put some people in a problem study group that showed promise. While it wasn't that much better than a placebo in some statistics, the clinical findings indicated it was worthwhile.

My guess is that if you extended the time with the group, the scores would greatly improve just like with cognitive behavioral therapy.

I can tell you from personal experience that if I had learned coping mechanisms for dealing with my NLD when I initially became depressed several years ago, I honestly feel I wouldn't have needed meds.

As far as SSRIs having minimal side effects, I greatly beg to differ. Here is a study on the cognitive damage that results.

I do have to laugh at the notation that the cognitive problems may be from depression itself. I am so tired of people's "illness" being blamed for side effects. As one who had word retrieval problems that were greatly worsened by meds, I can tell you that this is not from the depression.

Other side effects I have read about are osteoporosis, diabetes, vision problems, and memory loss. Of course, they will also blamed on the illness. (sigh).

Please understand that when someone feels that life isn't worth living, I do understand why ADs would be needed. But frankly, I am so tired of these drugs being prescribed for every medical condition on this universe without any regard for long term side effects.

Dinah, I applaud you by the way for your restraint in wanting to prescribe these meds wily nily. Too bad most medical professionals aren't like you.


Douglas Eby said...

Much depression is rightfully framed as pathology, but Eric Maisel, PhD, for one, talks about depression and dysthymia being an existential issue, especially for artists - and that it can be modulated if not prevented with adequate meaning-making in one's life. On my site are articles and interviews with Eric Maisel, and a video on the page Depression and Creativity.

shraddha said...

not related to the topic:

but do go and check out this blog

therapist talks about transference issues due to the blog.

Anonymous said...

Oh my goodness! I don't like to take panadol when i'm sick as sick - i don't think i would manage well with other type medications when i'm feeling well.


Anonymous said...

I read this yesterday and wondered why this post focused just on pills as primary preventive interventions. I share Dinah's concerns that the risk-benefit ratio is troubling in the case of primary prevention.

What about other more benign primary interventions? Like getting a dog or at least visits from a therapy dog if the stroke patient is in a nursing home or rehab facility and thus unable to have a pet, take up gardening or at least care for a houseplant, improve their sleep hygiene, take up modified yoga or at least breathing exercises, etc.

It seems to me that there are lots of potential things to study in primary prevention, though there are certainly some problems:

1) impossible to do double-blind rct experiments in some cases--what's the blind placebo-equivalent for a therapy dog?

2) funding for these kinds of experiments is an even bigger problem. Since you can't patent therapy dogs, etc., corporations aren't going to fund this kind of research. Government and non-profit organization funds are a potential source, but there are many competing demands from the families of those who are already in urgent need of tertiary interventions.

Even so, isn't there at least some positive evidence that exercise can help prevent or reduce the severity of depression?

Anonymous said...

Perhaps depression is just a slowing of growth of new neurons.

Matt said...

Meg- you bet there have been studies to show the positive benefits of exercise on depression- here's one
Article is from the UT Southwest med center
references a study published in the American Journal of Preventive Medicine

I'm in agreement with you that the current philosophy of science and the mores in medicine regarding evidence (double blind as the gold standard) skew exploration of therapy toward pharmaceuticals.

Anyway I think it's always interesting that there is a willingness to charge ahead with medication that might harm patients more than do good, while exploring therapies which might do nothing more than do good are blown off as complete wastes of time and energy. I think every therapy deserves scientific scrutiny to determine efficacy, and the fact that we have yet to come up with adequate ways to asses therapies like pet therapy, therapeutic gardening, etc makes me wonder how innovative medical science can really be.

ASDFGHJK said...

"Now I'm waiting for a study to see if prophylactic antidepressants are useful in other at-risk groups"
"Prophylactic Treatment of Interferon-Induced Depression in Hepatitis C Patients"

(In Germany prescription of prophylactic antidepressants are quite common when you undergo Interferon therapy due to Hepatitis C - I was told two year ago by my internist. She advised me to start with a SSRI a month before the Interferon/Ribavirin medication.
I was quite surprised about this suggestion after learning about the potential side-effects of SSRIs - especially as I have no history of depression (at least not officially diagnosed ;-)).
I prefered to go thru the 12 month therapy without antidepressants....)