There is no real evidence for the chemical imbalance theory of depression, in fact the meme about chemical imbalance was begun by pharmacuetical companies to explain how SSRI's work. That, and the failure of many of the new reuptake inhibitors, suggests that depression is not caused by chemical imbalances.
This could easily suggest to a casual reader (particularly one that is a part of a pick-yourself-up-by-your-bootstraps culture) to forgo pharmaceutical help.
I cannot speak on that and recommend professional help.
When someone starts out on antidepressants, their neurotransmitter [1] levels return to normal almost immediately. However, patients usually only begin to see improvements 2 - 4 weeks later. This wouldn't be the case if depression was simply due to lowered neurotransmitter levels.
However, all is not lost. A new theory suggests that patients have a lowered rate of neurogenesis (creation of new brain cells) and that serotonin is crucial in kick starting the process.
[1] Patients usually have lowered levels of Serotonin, norepinephrine and dopamine.
To say that depression is a chemical imbalance is to over-simplify the cause and treatment.
People hearing the chemical imbalance hypothesis may think that there's no effective evidence based therapy available, or that they will need meds for the rest of their life, or that they are going to relapse for the rest of their life.
That's not true. There are effective, evidence based, talking therapies. The most well known (Cognitive Behaviour Therapy) is simple to understand, easy to apply, and can be given by therapists or can be self-applied through websites (the Australian "Mood Gym" is one) or books ("mind over matter" is a good example).
A person given just meds will be more likely to relapse than someone given meds and CBT.
> I cannot speak on that and recommend professional help.
Yes, professional help is important. In the UK front line treatment for mild to moderate depression is not medication, but is CBT. And CBT should be used for other illnesses too.
My emphasis on things like CBT is because they have been shown to work; not because I don't think that depression is a "real illness'. See, for example, the use of CBT to treat pain suffered by cancer patients.
in fact the meme about chemical imbalance was begun by pharmacuetical companies to explain how SSRI's work
Just as a gut-check here, are you saying that the pharma companies actually came up with a drug, passed it through human trials and everything, and then came up with the reason for its existence? I'm skeptical.
I don't care enough about your ridiculous statement to go dig up evidence, but I care enough to relate my own anecdote: I have chemically induced depression in myself, as a side effect of a drug. As soon as I went off the drug, the depression went away.
I am a depression patient. It is certainly true that various substances can induce depression. I do not believe that the original poster was implying that depression is without very real biological causes; merely that these causes are more nuanced than the phrase "chemical imbalance" implies. Here is some food for thought.
SSRIs, or serotonin reuptake inhibitors, are the most commonly prescribed antidepressants in the United States due to their relative safety and efficacy. It is widely thought that these drugs achieve effectiveness through their ability to increase serotonin levels in the brain. Now, here comes the mystery: while serotonin levels rise almost immediately following introduction of the drug, the antidepressant effects do not become apparent until several weeks of treatment have passed. Why is that? No one knows for sure, but a few interesting theories have emerged.
The most interesting theory, in my opinion, involves hippocampal neurogenesis and BDNF levels. A few recent studies have shown that one thing that the SSRIs share in common is that they all promote neurogenesis in the hippocampus. A further study showed that the antidepressant effects of SSRIs on behavior in rats exposed to artificially induced stressors could be completely nullified by slightly irradiating the hippocampus, thus negating the growth of new neurons promoted by the SSRIs. The antidepressant effect was gone even though serotonin levels remained elevated.
This conclusion provided compelling but not conclusive evidence that neurogenesis is involved in antidepressant effectiveness. Yet even here, the picture was not altogether clear: while patients diagnosed with clinical depression generally show less hippocampal neurogenesis than controls, it is not at all clear whether this deficit is a cause or effect of clinical depression. Is it possible that depression, once established, can cause physical changes in brain structure? If so, that might explain why cognitive behavioral therapy in conjunction with antidepressant medication is a more effective depression treatment than either of the two alone.
Interestingly enough, strenuous aerobic exercise is known both to be an effective treatment for mild to moderate forms of depression as well as a promoter of hippocampal neurogenesis. An increasing number of psychiatrists are in fact prescribing exercise regimens as treatment for some forms of depression because it seems to work.
The bottom line is: there's a lot we don't know about depression, and while we have effective treatments, the reality is that the causes of depression simply cannot be adequately summed up as a "chemical imbalance." Drugs are appropriate for some patients and inappropriate for others. I encourage anyone interested in the subject to do some reading, as the brain is (at least, to a layman like me) the most fascinating information processing system ever.
While we don't know the exact causes, and there are complex factors in play, it is most certainly a chemical imbalance. Imagine you could take a perfect chemical "snapshot" of the brain/body when it's in a normal mood and again in depressed state. Do you seriously think there would be no difference chemically?
I've take SSRIs off & on for the last 15 years. I'm currently on them after experiencing suicidal depression this summer. (I suspect it was partially induced by taking Chantix.)
Exercise can help, but in my case it doesn't make much difference. When my latest onset hit I was (and still am) in the best shape of my life and maintaining 10% body fat. I've been doing Crossfit for the last 15 months. Very strenuous.
"Do you seriously think there would be no difference chemically?"
No, I do not think that. In fact, I stated quite clearly that depression causes measurable changes in brain morphology and function. My entire argument was to support the assertion that the phrase "chemical imbalance" is merely an insufficient label for a complex psychological and biological phenomenon.
