Sturnam
Bluelighter
- Joined
- Aug 12, 2008
- Messages
- 738
You're missing the point of this thread and you've been missing the point of the thread since the first post. I do not contend that AD's do not work. I never have done.
This thread is not debating whether or not AD's work... it's debating whether or not the monoamine hypothesis works...
And for what it counts, I've already cited that I responded very well to Agomelatine, an 'anti-depressant' if you want to call it that. Please stop de-railing the thread with these constant remarks.
You seem to be mixing up the biochemical hypothesis of depression (general! not just monoamine based), the monoamine hypothesis, and the role of antidepressant in it all. Just because the serotonin theory of depression have proven to be less than true doesn't mean that ALL neurobiological theories of depression are false. Because you started this thread with...
'There is not one shred of credible evidence that any respectable scientist would consider valid, demonstrating anything that Psychiatrist's call 'mental illness' are bio-chemical imbalances of the brain.'
And that is just patently false. Here is a short list:
Influence of life stress on depression: moderation by a polymorphism in the 5-HTT gene.
A polymorphism (5-HTTLPR) in the serotonin transporter promoter gene is associated with DSM-IV depression subtypes in seasonal affective disorder
Serum dehydroepiandrosterone (DHEA) and DHEA-sulfate (S) levels in medicated patients with major depressive disorder compared with controls.
Gender differences in serum testosterone and cortisol in patients with major depressive disorder compared with controls.
HPA-axis regulation at in-patient admission is associated with antidepressant therapy outcome in male but not in female depressed patients.
Rapid treatment response of suicidal symptoms to lithium, sleep deprivation, and light therapy (chronotherapeutics) in drug-resistant bipolar depression.
Rapid and sustained antidepressant response with sleep deprivation and chronotherapy in bipolar disorder.
S-adenosyl methionine (SAMe) versus escitalopram and placebo in major depression RCT: Efficacy and effects of histamine and carnitine as moderators of response.
Efficacy and safety of levomilnacipran sustained release 40 mg, 80 mg, or 120 mg in major depressive disorder: a phase 3, randomized, double-blind, placebo-controlled study.
A randomized, double-blind, placebo-controlled 8-week trial of the efficacy and tolerability of multiple doses of Lu AA21004 in adults with major depressive disorder.
And on and on and on. I could go on, but I'm sure you get my point, and I doubt that you'll read most/any of these articles anyways. Again, there can be other biochemical imbalances/alterations besides serotonin/monoamines that will contribute towards depression. And sure, maybe this is a round-about way of evaluating biological abnormalities, but you can't exactly take brain tissue from humans. It's pretty unethical. However, if you're willing to look at animal data from depression models, I would be more than happy to find those for you, and I'll even sent you the full texts for free. The animal models have direct brain tissue samples, from different time points, different treatments, etc. But because I expect that you'd want human data, treatment is generally the best data we have as a proxy for underlying pathology.
Now, I would agree with you if you would contest the validity of the idea that improvement of depression with treatment of a drug implies that the drug's mechanism is the source of the problem; i.e. if SSRI's work for depression, then serotonin must be involved in depression. With SSRI's, it's more likely that downstream effects that take longer to kick into gear (3-5 weeks, along the timeline for actual response with SSRI's) are responsible for the antidepressant effects. And here are some sources for that:
Neurobiological mechanisms involved in antidepressant therapies. (serotonin autoreceptors)
Antidepressants increase human hippocampal neurogenesis by activating the glucocorticoid receptor (neurogenesis)
Interaction between BDNF and Serotonin: Role in Mood Disorders (role of brain-derived neurotrophic factor/BDNF)
And more sources that directly address post-mortem/non-invasive imaging brain abnormalities in humans. I should add that I see structure and function as intimately related, especially for neural processing or alterations, and that biochemical changes can most definitely alter the structure of various brain regions.
Brain structural and functional abnormalities in mood disorders: implications for neurocircuitry models of depression
Structural brain abnormalities in major depressive disorder: a selective review of recent MRI studies.
Hippocampal atrophy in recurrent major depression
Circadian patterns of gene expression in the human brain and disruption in major depressive disorder
Brain Activity in Adolescent Major Depressive Disorder Before and After Fluoxetine Treatment
First-Episode Medication-Naive Major Depressive Disorder Is Associated with Altered Resting Brain Function in the Affective Network
Reduced brain leptin in patients with major depressive disorder and in suicide victims
Brain Biopsy Findings Link Major Depressive Disorder to Neuroinflammation, Oxidative Stress, and Neurovascular Dysfunction: A Case Report
However, I do agree with the general sentiment stated by herbavore, yourself, and others, which is that depression is a complex, heterogeneous disease, and the monoamine hypothesis is stupidly simply, and does not fit with lots of observed data (as you correctly pointed out). It is likely that the downstream effects of SSRIs/SNRIs/etc are responsible for the antidepressant action, and not acute changes in serotonin/norepinephrine/dopamine.
But this does not mean that there are no biochemical changes in depression. Indeed, I believe that who we are, our mood, anxiety, personality, and everything else about us is determined by our biology. Opioids make people euphoric, cocaine can make you an arrogant ass, and LSD can change your thought patterns in incredibly unique ways. And all this happens through manipulation of our brain's biochemistry.
Depression is most definitely understudied, and I would say that we still have absolutely no idea what causes it, what the variations in depression are (situational vs. life-long vs. Seasonal affective disorder vs. major depressive episodes, vs. dysthymia, etc), or how to adequately treat it. Right now we do the best with what we have, which is unfortunately a very narrow band of therapeutics, with most based off monoamine alterations. However, ketamine is doing remarkably well in clinical trials, and is particularly wonderful at inducing a very rapid antidepressant response, and it is not an SSRI. Again, this seems to lend credence to the theory that some alteration in the brain can be rapidly reversed by ketamine, producing an antidepressant response. For the example of ketamine, they think that it is probably related to increased dendritic spine growth (essentially more connection between neurons).(Serial infusions of low-dose ketamine for major depression)
Lastly, medication should always be used in conjunction with therapy, talking to a psychiatrist, therapist, or other. And this is the key bit of information that is often left out, and that people skip out on. Sure, it's much easier to pop a pill every day than to get down to your insecurities/worries/fear/ingrained behavior that contributes to depression, but medication is also much less effective in the absence of therapy. And I think this gets down to the crux of the issue, which is whether the patients need antidepressant medication, or simply some help and guidance through a rough patch in their life.
There are some people that literally cannot get out of bed, cannot keep appointments, and cannot function without antidepressants. However, I see the utility of antidepressants as that little extra push to help people make positive changes in their lives; changes that would be difficult/impossible without the help of medication. Their use is to help people overcome that initial barrier, so that they can go exercise, eat healthy, go to therapy, and other activities that will help ameliorate their depression. And I don't think that most people with depression are in this situation; I think that the vast majority of depression is based on situation; they parents/child/spouse dies, trouble finding work, being alone, no friends, or what have you, and would benefit more from therapy.
I don't really expect you to read most of the references, I just wanted to show you that there is substantial evidence for neurobiological underpinnings in depression for at least a subset of patients, with the most robust evidence of neurobiological abnormalities for severe MDD/lifelong depressive patients, IMO. That is not to say that serotonin or monoamines are the only cause, but they may be involved for some patients. If nothing else, I would really encourage you to read a review on the neurobiology of depression. I think that you might find that the new reviews focus less on increasing serotonin, and look more at neurogenesis, improved synaptic connections, and other theories of depression.