except that the serotonin model of depression has been disproven without a shadow of a doubt:
https://www.youtube.com/watch?v=ISptt3CRAqc
the device may have some effect as placebo but if that's what you're going for, there are many other cheaper alternatives
I'd hesitate to say that. First, treatment and cause are obviously not the same thing: increasing serotonin levels in a person and that making their depression 'go away' does not mean that low serotonin levels was the original cause for the depression. So in that sense, there isn't really a "serotonin model of depression"--we're talking about treatments and if they're effective. It's also true that for a lot of mild/moderate depression (which can still be serious in terms of suicide risk) SSRIs do not do hugely better than placebo, although they do perform on average better than placebo (~20%). However, for the more severe cases of unipolar major depressive disorder, SSRIs (and other antidepressants, for that matter) are significantly more effective than placebo.
It's also reasonable to point out that the serotonin system likely has an effect on bipolar depression, given the pretty convincing evidence that SSRIs can induce full blown mania in bipolar patients--even those who have not had a full manic episode before (only hypomanic ones).
Basically: it's complex. There are other confounding factors, too, such as lower serotonin levels being linked with aggression and impulsivity (and suicide) even in patients who don't report or show any depressive symptoms. So there might also be non-'it cures depression' arguments for SSRIs as preventatives, although there isn't a lot of research that I've read into that in particular.
This isn't an argument for this device in particular, though--my bullshit detector is being set off pretty rapidly by the site and claims.
Edit: some clarifications, rewordings.
One of the interesting points the speak made was: The difference in response recovery rate between studies where the patients know they will receive an anti-depressant (drug vs. drug) and studies where they know they may recieve a placebo (drug vs. placebo) is bigger than the difference in recovery rate between drug and placebo. He then points out that due to side effects, patients are fairly reliably able to determine whether they are on a placebo or on an anti-depressant.
When discussing the equivalent efficacy of SSRIs and SSREs he says: "Were there any truth in the serotonin model of depression, and I don't know any responsible researcher in the area who still contends there is. (It's only in marketing where you still see that talked about) Where there any truth to that, SSRE's should not help people recover from depression, it ought to make them depressed" Link to time: https://www.youtube.com/watch?v=ISptt3CRAqc#t=1865
If that is correct, I think it might be valid to claim that " that the serotonin model of depression has been disproven" although I think "beyond a shadow of a doubt" seems hyperbolic. It might be also be argue that "the serotonin model of treating depression" might be clearer.
The serotonin system having an effect on mood, though, or SSRIs as treatments for depression: that's an entirely different realm. They do seem to be much less effective on people who are on the minor/moderate end of the spectrum, and are definitely less effective than they were once advertised as being. There are a lot of reasons (aforementioned side effects, effectiveness of various types of therapies, prevalence of environmental effects in many people's depression) to try other options than SSRIs if you aren't severely depressed--but the clinical evidence for their efficacy in treating severe depression isn't really arguable either.
As a side note, there's some fairly recent research from the middle of last year (see these for the summary version: http://en.wikipedia.org/wiki/Tianeptine and http://en.wikipedia.org/wiki/Reuptake_enhancer) that shows that the only drug ever released as an SSRE probably isn't effective because of that action (if it even is an SSRE--see the second link).
Serious? Man, that would probably piss a lot of people off. Is this like air quotes "disproven" or a pretty solid actual seal of peer-reviewed disproval?
Other lines of counter-evidence exist, including that there are drugs that stimulate other neurotransmitters that help with depression, that there are drugs that lower serotonin that help with depression, that there's no coherent explanation for how serotonin's main effect (neurogenesis) would actually lead to modulating depression, etc.
Academia seems focused on the role of the NMDA receptor now, but it'll likely be another red herring too.
I recommend reading http://slatestarcodex.com/2015/01/05/chronic-psychitis/ just to get clear on how much of what we're doing is repeatedly picking correlated symptoms and assuming they're the cause.
As a side note, regarding placebos, the more expensive ones often work better than the cheaper ones. http://www.sciencedaily.com/releases/2008/03/080304173339.ht...
you don't always need the most expensive placebo, just something which is deemed to have value and not free or without effort
for example, saline solution which 'burns' a little when injected is more effective than simply injecting pure H2O, so in the sense that it generates slight discomfort it is not 'free'