[vegannet]

I’ve always understood the chemical imbalance description of depression (and other mental health conditions) to be a casual way of describing the conditions as being part of the person rather than a choice — and not a way to describe the internal mechanics of the conditions. I’ve found it effective when having conversations about mental health conditions: how would you describe depression without using that phrase, based on what this paper reveals?

[anaphor]

I'm not saying there isn't a biochemical component to depression (or any other mood disorders). The specific theory that I'm talking about is "low serotonin causes depression" (as in the proximate cause, not the ultimate cause). When SSRIs were first discovered to be useful for treating depression, one of the theories about why they worked was that they boosted levels of serotonin, but we know now that's not true. It doesn't mean it can't be explained in other ways (like the one this article discusses).

Also, if there is a behavioral component to depression as well, then it doesn't necessarily mean someone is to blame for their disorder. You don't control the environment you grow up in, which has an enormous impact even on traits that are highly heritable (the whole subject of heritability is very misunderstood anyway).

So basically if I were going to describe depression's cause, I'd say it's a mixture of biochemical reactions, behavioural traits, and environmental stresses that cause it.

[ineedasername]

A behavioral component manifests itself as a chemical process within the brain. So it may be used to explain the cause of certain chemical processes, but it's still the chemical processes that have to be dealt with. Though it doesn't necessarily follow that a chemical intervention is necessary: If the cause of the chemical change was behavioral, the solution might be as well, such in the form of various type of therapy.

[sjg007]

In the article they discuss that known SSRIs weakly bind a different receptor which may be why they have an antidepressant effect. It would explain why more specific SSRIs that are thought to target serotonin receptors selectively do not work. That they see a bunch of them doing the same thing is pretty convincing.

to quote: "Now to the BDNF hypothesis. I used the phrase “unknown mechanism” above, and that’s exactly what this work may have cleared up. The authors show that when the TrkB protein forms a dimer in the cell membrane, a binding site for small molecules is formed at the interface. A whole list of known antidepressants (fluoxetine, imipramine, venlafaxine, moclobemide, ketamine, esketamine, and R,R-hydroxynorketamine) bind to this site at about 1 micromolar levels (and can displace each other in binding assays(, while a set of control CNS compounds like chlorpromazine, diphenhydramine, and indeed S,S-hydroxynorketamine do not. It will not be lost on those who’ve done research in the field that the antidepressant compounds listed above have been thought to work through completely different mechanisms. "