Thursday, August 15, 2013

Good gap arguments?

From Angus Menuge ("Against Methodological Materialism," Waning of Materialism, p 381):

[E]ntirely materialistic science employs gap arguments routinely when explaining unlikely historical events. The most widely accepted explanation of the geologically rapid, widespread extinction of dinosaurs invokes a rare, but fully materialistic event: asteroid impact. Part of the evidence for this event is that none of the processes believed to be going on at the time (including likely diseases - initially a competing hypothesis) are sufficient to account for such a catastrophic extinction. In other words, there is a gap between these processes and the fact of extinction. Asteroid impact was then hypothesized as a possible cause, leading to independent predictions of shocked quartz in the Cretaceous-Tertiary boundary, which were subsequently confirmed. Not only is this gap argument completely materialistic, it is also a good one, because it depends on the confirmation of independently testable predictions that discriminate between the asteroid hypothesis and its competitors.

In fact, historical science of all kinds is filled with gap arguments. There is a gap between the unloaded military antique mounted on a wall and the deceased Colonel Mustard who was somehow killed using the antique, and this gap may be best explained by the intelligent agency of a murderer. There is a horrific numerical gap between the population records for Jews and Slavs before and after the Second World War that is best explained by deliberate genocide. There may be a gap between a student's own creative ability and the spectacular slide show on impressionism he presented, best explained by the artistic skill of impressionist artists. Evolutionary scientists themselves frequently employ gap-arguments, claiming that there must have been intermediary creatures between those whose fossils have actually been discovered, for otherwise there is no suitably gradual explanation of the presumed transitions. In general, a good gap argument is based on a careful assessment of what the normal course of nature is capable of doing, thereby providing evidence of an objective gap in nature, not merely a gap in our knowledge, and this leads to the postulation of some additional factor or agency whose causal powers are known to be capable of filling the gap. Good gap arguments are therefore not arguments from ignorance but arguments from knowledge, both of what nature is normally capable of doing, and of the resources capable of doing more.

Sunday, August 11, 2013

Candid med student thoughts on depression and drugs

I posted the following over on Dan Phillips' post:

Hi Dan,

Thanks for your post. I'd like to make some comments please.

1. Since I think it's relevant, I'll start by saying I'm a Christian (Reformed) med student.

2. It sounds like one of the main things you're arguing against is chemical imbalance theories for depression. Arguing against or at least highly suspect of the idea that depression is caused by low levels of serotonin in the brain. I agree there are problems with chemical imbalance theories including the serotonin one. But I don't think this means we should throw out the baby with the bath water.

3. You mention: "I talked to my doctor about the very serious depression I was beginning to experience some decades ago, he told me about the lack of serotonin in my brain, and wanted me to take a pill for it." Obviously a lot has changed in medicine in "decades." Also, we don't know if he was a psychiatrist.

4. Could I humbly suggest you might be burning a strawman, at least in the following respects?

a. To my knowledge and in my experience, many if not most physicians are quite aware our understanding of depression is incomplete. I think the article and video you cite are indicative of this.

b. Many if not most physicians are aware of various theories for depression including low serotonin levels. But again to my knowledge and in my experience I don't know a single contemporary physician who believes low serotonin levels are the be-all and end-all to explaining depression. Many if not most seem to think there could be a number of factors involved.

Take modern psychiatrists. They consider various models including the "bio-socio-psycho-spiritual" model. They'll try to figure out if the person's condition could be due in part or entirely to biological factors (e.g. hypothyroidism, genetic conditions). Also they'll try to see if there are social factors in the person's life to consider (e.g. stressful job, abusive relationships, financial trouble). They'll ask if there are psychological factors involved (e.g. suicidal ideation). And they'll query a person's religious or related beliefs. They're trained to consider the whole person.

c. Indeed, there's quite a bit of debate among psychiatrists over the American Psychiatric Association's recently published DSM-V including over criteria for clinical depression.

d. I don't think it's true, but say it's true most physicians subscribe to the serotonin theory. Nevertheless I would think many if not most understand there's a tremendous difference between correlation and causation.

e. Related, I seriously doubt most physicians would say "mental issues, emotional issues, behavioral issues" are "cut and dried." In fact, we're explicitly taught in med school and explicitly told by doctors in the various hospitals and wards we're required to rotate through that mental issues are anything but. We're explicitly told how mental issues are so difficult and complex to pin down, how ill-defined they are, etc. Indeed, this is one reason why most med students don't wish to go into fields like psychiatry and neurology, because these fields are regarded as less "cut and dried" than other fields in medicine, and most med students seem to tend to prefer fields where there are more concrete diagnoses, treatments, and the like.

5. I could be mistaken, but I suspect to the extent people think "the lack of serotonin" in one's brain is what causes depression is more something large swathes of the media has perpetuated than what doctors today generally subscribe to. For instance there are some studies which have shown selective serotonin reuptake inhibitors (SSRIs) have been successful in treating depression in HIV positive patients. The media could easily take this to indicate serotonin deficiencies cause depression. But physicians know this doesn't mean we should therefore extrapolate from these studies to say SSRIs always work for treating all depressed patients. After all, there could be many other reasons why SSRIs worked in these HIV positive patients which can't be applied to other sorts of patients.

6. A lot hinges on what we mean by depression. For what it's worth, psychiatrists generally classify depression into at least four groups:

a. Adjustment disorder with depressed mood. Depression occurring in reaction to an identifiable stressor or adverse life situation (e.g. death of a loved one, divorce, financial crisis).

b. Mood disorders secondary to illness and medications. Depression as a result of conditions like arthritis, stroke, alcoholism, drugs, etc.

c. Bipolar disorders. There are two subcategories here: mania and cyclothymic disorders. A manic episode is a mood change characterized by elation with hyperactivity, flights of ideas, distractibility, little need for sleep, among others, which swings into depression, anger, aggressiveness, and so forth. Cyclothymic disorders are chronic mood disturbances with episodes of depression and hypomania.

d. Depressive disorders. There are three subcategories here: dysthymia; premenstrual dysphoric disorder; and major depressive disorder. Dysthymia is chronic depressive disturbance generally milder but longer lasting than major depressive disorder. Premenstrual dysphoric disorder is depression as a result of the menstrual cycle. Finally, major depressive disorder has three further divisions: major depression with atypical features; seasonal affective disorder; and postpartum depression.

For example, take postpartum depression. It seems uncontroversial to say hormonal changes and psychosocial stressors in the life of a woman who has recently given birth play large roles in postpartum depression. So this sort of depression would have an arguably strong connection to the physiological (hormonal changes). A doctor might try to treat her postpartum depression with non-pharmacological methods (e.g. psychotherapies), but I don't see that there's anything askew about considering hormonal treatment to better regulate her hormones as part of the arsenal.

7. Regarding medical "tests."

a. Tests can be used for different purposes. For example, there's a difference between using a test for screening and using it for diagnosis.

b. Tests have their limitations. Some tests are more (or less) accurate at finding what they're supposed to find than other tests. Just Google sensitivity and specificity of tests for starters.

c. Tests are only able to find what they're designed to find. Nothing less, nothing more. A chest x-ray is useful for identifying pneumonia, but not useful in identifying brain cancer. An EKG is useful for identifying electrical abnormalities in the heart, but not useful in identifying kidney disease.

d. Some diseases or conditions don't need tests to be diagnosed. It doesn't take a test to diagnose that someone has been stabbed if someone presents with, say, a bleeding wound and says he got into a fight and has been stabbed. A test could be used to see where the knife punctured or where to operate. But it'd be superfluous to order a test to confirm they've been stabbed.

Or to take a more mundane example, physicians don't really need to order a test to diagnose the common cold. It can be done based on the patient's history and/or a quick physical examination. Their signs and symptoms usually say it all.

e. As for depression. The diagnosis of a depressive episode includes determining the psychiatric category and determining if the etiology is idiopathic or related to an underlying systemic or neurologic condition, substance use, or prescription medication side effect.

f. The diagnosis of depression is largely based on patient history and mental status examination. Also, there's usually an evaluation for suicide risk. And a patient history would normally include a comprehensive medical history, exploration of comorbid psychiatric disorders like substance use, and of course a family history.

g. There's no evidence to support routine laboratory testing in the diagnosis of depression. However, a complete blood count, a basic chemistry profile, liver function tests, TSH, RPR, B12, and folate levels are helpful when underlying medical conditions are suspected.

8. I would think most people don't directly see a psychiatrist. Rather I would think most people are probably referred to a psychiatrist by another physician. Generally speaking, a referral to a psychiatrist most likely means the referring physician thinks the person's illness would be best suited for a psychiatrist to treat or manage. This in turn could quite possibly mean a physician has already tried to address non-psychiatric aspects of the person's illness. In short, psychiatrists are generally consulted primarily for psychiatric and related concerns, not for non-psychiatric concerns.

9. Richard Winter over at Covenant Seminary seems to be a good Christian psychiatrist.

Thursday, August 15, 2013

Good gap arguments?

From Angus Menuge ("Against Methodological Materialism," Waning of Materialism, p 381):

[E]ntirely materialistic science employs gap arguments routinely when explaining unlikely historical events. The most widely accepted explanation of the geologically rapid, widespread extinction of dinosaurs invokes a rare, but fully materialistic event: asteroid impact. Part of the evidence for this event is that none of the processes believed to be going on at the time (including likely diseases - initially a competing hypothesis) are sufficient to account for such a catastrophic extinction. In other words, there is a gap between these processes and the fact of extinction. Asteroid impact was then hypothesized as a possible cause, leading to independent predictions of shocked quartz in the Cretaceous-Tertiary boundary, which were subsequently confirmed. Not only is this gap argument completely materialistic, it is also a good one, because it depends on the confirmation of independently testable predictions that discriminate between the asteroid hypothesis and its competitors.

In fact, historical science of all kinds is filled with gap arguments. There is a gap between the unloaded military antique mounted on a wall and the deceased Colonel Mustard who was somehow killed using the antique, and this gap may be best explained by the intelligent agency of a murderer. There is a horrific numerical gap between the population records for Jews and Slavs before and after the Second World War that is best explained by deliberate genocide. There may be a gap between a student's own creative ability and the spectacular slide show on impressionism he presented, best explained by the artistic skill of impressionist artists. Evolutionary scientists themselves frequently employ gap-arguments, claiming that there must have been intermediary creatures between those whose fossils have actually been discovered, for otherwise there is no suitably gradual explanation of the presumed transitions. In general, a good gap argument is based on a careful assessment of what the normal course of nature is capable of doing, thereby providing evidence of an objective gap in nature, not merely a gap in our knowledge, and this leads to the postulation of some additional factor or agency whose causal powers are known to be capable of filling the gap. Good gap arguments are therefore not arguments from ignorance but arguments from knowledge, both of what nature is normally capable of doing, and of the resources capable of doing more.

Sunday, August 11, 2013

Candid med student thoughts on depression and drugs

I posted the following over on Dan Phillips' post:

Hi Dan,

Thanks for your post. I'd like to make some comments please.

1. Since I think it's relevant, I'll start by saying I'm a Christian (Reformed) med student.

2. It sounds like one of the main things you're arguing against is chemical imbalance theories for depression. Arguing against or at least highly suspect of the idea that depression is caused by low levels of serotonin in the brain. I agree there are problems with chemical imbalance theories including the serotonin one. But I don't think this means we should throw out the baby with the bath water.

3. You mention: "I talked to my doctor about the very serious depression I was beginning to experience some decades ago, he told me about the lack of serotonin in my brain, and wanted me to take a pill for it." Obviously a lot has changed in medicine in "decades." Also, we don't know if he was a psychiatrist.

4. Could I humbly suggest you might be burning a strawman, at least in the following respects?

a. To my knowledge and in my experience, many if not most physicians are quite aware our understanding of depression is incomplete. I think the article and video you cite are indicative of this.

b. Many if not most physicians are aware of various theories for depression including low serotonin levels. But again to my knowledge and in my experience I don't know a single contemporary physician who believes low serotonin levels are the be-all and end-all to explaining depression. Many if not most seem to think there could be a number of factors involved.

Take modern psychiatrists. They consider various models including the "bio-socio-psycho-spiritual" model. They'll try to figure out if the person's condition could be due in part or entirely to biological factors (e.g. hypothyroidism, genetic conditions). Also they'll try to see if there are social factors in the person's life to consider (e.g. stressful job, abusive relationships, financial trouble). They'll ask if there are psychological factors involved (e.g. suicidal ideation). And they'll query a person's religious or related beliefs. They're trained to consider the whole person.

c. Indeed, there's quite a bit of debate among psychiatrists over the American Psychiatric Association's recently published DSM-V including over criteria for clinical depression.

d. I don't think it's true, but say it's true most physicians subscribe to the serotonin theory. Nevertheless I would think many if not most understand there's a tremendous difference between correlation and causation.

e. Related, I seriously doubt most physicians would say "mental issues, emotional issues, behavioral issues" are "cut and dried." In fact, we're explicitly taught in med school and explicitly told by doctors in the various hospitals and wards we're required to rotate through that mental issues are anything but. We're explicitly told how mental issues are so difficult and complex to pin down, how ill-defined they are, etc. Indeed, this is one reason why most med students don't wish to go into fields like psychiatry and neurology, because these fields are regarded as less "cut and dried" than other fields in medicine, and most med students seem to tend to prefer fields where there are more concrete diagnoses, treatments, and the like.

5. I could be mistaken, but I suspect to the extent people think "the lack of serotonin" in one's brain is what causes depression is more something large swathes of the media has perpetuated than what doctors today generally subscribe to. For instance there are some studies which have shown selective serotonin reuptake inhibitors (SSRIs) have been successful in treating depression in HIV positive patients. The media could easily take this to indicate serotonin deficiencies cause depression. But physicians know this doesn't mean we should therefore extrapolate from these studies to say SSRIs always work for treating all depressed patients. After all, there could be many other reasons why SSRIs worked in these HIV positive patients which can't be applied to other sorts of patients.

6. A lot hinges on what we mean by depression. For what it's worth, psychiatrists generally classify depression into at least four groups:

a. Adjustment disorder with depressed mood. Depression occurring in reaction to an identifiable stressor or adverse life situation (e.g. death of a loved one, divorce, financial crisis).

b. Mood disorders secondary to illness and medications. Depression as a result of conditions like arthritis, stroke, alcoholism, drugs, etc.

c. Bipolar disorders. There are two subcategories here: mania and cyclothymic disorders. A manic episode is a mood change characterized by elation with hyperactivity, flights of ideas, distractibility, little need for sleep, among others, which swings into depression, anger, aggressiveness, and so forth. Cyclothymic disorders are chronic mood disturbances with episodes of depression and hypomania.

d. Depressive disorders. There are three subcategories here: dysthymia; premenstrual dysphoric disorder; and major depressive disorder. Dysthymia is chronic depressive disturbance generally milder but longer lasting than major depressive disorder. Premenstrual dysphoric disorder is depression as a result of the menstrual cycle. Finally, major depressive disorder has three further divisions: major depression with atypical features; seasonal affective disorder; and postpartum depression.

For example, take postpartum depression. It seems uncontroversial to say hormonal changes and psychosocial stressors in the life of a woman who has recently given birth play large roles in postpartum depression. So this sort of depression would have an arguably strong connection to the physiological (hormonal changes). A doctor might try to treat her postpartum depression with non-pharmacological methods (e.g. psychotherapies), but I don't see that there's anything askew about considering hormonal treatment to better regulate her hormones as part of the arsenal.

7. Regarding medical "tests."

a. Tests can be used for different purposes. For example, there's a difference between using a test for screening and using it for diagnosis.

b. Tests have their limitations. Some tests are more (or less) accurate at finding what they're supposed to find than other tests. Just Google sensitivity and specificity of tests for starters.

c. Tests are only able to find what they're designed to find. Nothing less, nothing more. A chest x-ray is useful for identifying pneumonia, but not useful in identifying brain cancer. An EKG is useful for identifying electrical abnormalities in the heart, but not useful in identifying kidney disease.

d. Some diseases or conditions don't need tests to be diagnosed. It doesn't take a test to diagnose that someone has been stabbed if someone presents with, say, a bleeding wound and says he got into a fight and has been stabbed. A test could be used to see where the knife punctured or where to operate. But it'd be superfluous to order a test to confirm they've been stabbed.

Or to take a more mundane example, physicians don't really need to order a test to diagnose the common cold. It can be done based on the patient's history and/or a quick physical examination. Their signs and symptoms usually say it all.

e. As for depression. The diagnosis of a depressive episode includes determining the psychiatric category and determining if the etiology is idiopathic or related to an underlying systemic or neurologic condition, substance use, or prescription medication side effect.

f. The diagnosis of depression is largely based on patient history and mental status examination. Also, there's usually an evaluation for suicide risk. And a patient history would normally include a comprehensive medical history, exploration of comorbid psychiatric disorders like substance use, and of course a family history.

g. There's no evidence to support routine laboratory testing in the diagnosis of depression. However, a complete blood count, a basic chemistry profile, liver function tests, TSH, RPR, B12, and folate levels are helpful when underlying medical conditions are suspected.

8. I would think most people don't directly see a psychiatrist. Rather I would think most people are probably referred to a psychiatrist by another physician. Generally speaking, a referral to a psychiatrist most likely means the referring physician thinks the person's illness would be best suited for a psychiatrist to treat or manage. This in turn could quite possibly mean a physician has already tried to address non-psychiatric aspects of the person's illness. In short, psychiatrists are generally consulted primarily for psychiatric and related concerns, not for non-psychiatric concerns.

9. Richard Winter over at Covenant Seminary seems to be a good Christian psychiatrist.