As usual, vague terms like "90% accuracy" are thrown around without specifying what exactly they mean. Is that a 10% false positive rate? A 10% false negative rate? 90% accuracy over a representative sample of the general population?

Because the last one is what would seem to be implied, but I have a much simpler program, written in pure JavaScript, that is also 90% accurate at diagnosing Americans with depression: https://gist.github.com/osuushi/5297823

Since, according to the CDC[1], about 10% of Americans are depressed, my script will be accurate 90% of the time.

[1] http://www.cdc.gov/features/dsdepression/

90% isn't all that great of a result considering only about 6.7% of the US population suffers from depression each year[1] and the study was done in California. Just returning false would give you better accuracy.

Still Eliza on steroids is pretty cool. Can't wait till they integrate it into emacs.

[1] http://www.nimh.nih.gov/statistics/1MDD_ADULT.shtml

This is interesting to me because... is there even a scientific definition of depression yet? Such that, if you have a defined list of symptoms, you are definitely depressed, and if you don't, you are definitely not depressed?

If not, we're at best talking about a magnitudinal thing or a probability thing. Like a Bayesian thing where each symptom's presence updates the probability of the person being depressed, which is turn based off of a database of previous cases of diagnosed depression and what symptoms they had.

But even that may be circular, ultimately. It could just as well be that depression is a vague category of similar symptoms that each come from a wide variety of scientific causes.

This is not to be mistaken for saying it doesn't exist or that it's all in someone's head - it's more just to say that if someone has depression, they have something that may deserve treatment and sensitivity, but that it's something that we still do not know exactly how to describe or diagnose, and so therefore we will just call it "depression" in the meantime. But what if we've sort of collectively forgotten the "in the meantime" part?

"SimSensei can work out whether you’re exhibiting signs that indicate depression"

Im not sure I totally buy it - Im sure it can pick up the signs with 90% accuracy but how often do the signs actually correspond to a clinically depressed person. Just because your in a down mood at one moment does not mean you are depressed - depression is just a lot more complex than that. Im not sure that this would be of much use in accurate diagnosis although it seems like pretty interesting tech.

First of all, this is blog spam, and the OP has apparently never tried viewing their own site on a tablet.

Second, where's the methodology.

Third, it's not the Kinect doing the diagnosing, it's the computer vision algorithm

Doctors tried something similar with paper forms in the 60s. It was pretty disastrous, given depression is such a complex, "3d" kind of issue. Adam Curtis explored this theme in perhaps his best series of documentaries, "The Trap" - http://www.youtube.com/watch?v=WbRApO3k_Jo

As if depression were a Boolean label.

If it's as accurate as the team says it is, this is pretty astounding IMO. They'd have to be capturing some sort of baseline in the beginning of the conversation, and recording relative shifts of variables (ie; smile, eye shift/location) to come up with how "depressed" the person is. Just writing some software that says "oh this person is looking down" probably wouldn't cut it-- because shy people look down too. I noticed in the demo it seemed as if it started monitoring these things after certain questions were asked, which would be the correct way to measure a shift from baseline. Elicit a predictable period of what could be change and record.

I'm tempted to send this to my shrink to see if he'll take the hint and cut his prices. I'm not optimistic, though.

Actually, I'm looking to do something like this in related applications. Just need to find time to go through the kinect capabilities....my own unit has been gathering dust on my shelf for a while. Anyone in southern california (LA area or within driving distance) want to talk about this?

Do psychiatrists' diagnoses of depression even agree with that level of accuracy amongst themselves?

Maybe its just most Xbox360 users are depressed about spending $400 just so they can play Halo.

How does it determine depression vs boredom?

Wow - So has those 20 question things that have been in magazines and tabloids for 40 years.....

> This is interesting to me because... is there even a scientific definition of depression yet? Such that, if you have a defined list of symptoms, you are definitely depressed, and if you don't, you are definitely not depressed?

It depends a bit on what you mean. In the U.S. at least, diagnosis of depression is generally based on the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM).[1] That lists a number of disorders that would be categorized under "depression", including "Major Depressive Disorder", "Dysthymia", and the catchily named "Depressive Disorder Not Otherwise Specified".

In the DSM, these disorders are all treated as syndromes, meaning they are defined entirely by symptoms. They may have organic causes (troubles with neurotransmitters, etc.), but the definition of each disorder does not address that issue. This is in contrast to something like influenza, which refers to a particular organic cause (infection by a certain kind of virus).

As for the actual definitions, they vary in how specific they are. Major Depressive Disorder is quite specific, requiring certain kinds of episodes to occur with specified frequencies and lengths. On the other end of the scale is DD-NOS, which is essentially defined as a depression-ish thing that doesn't fit into any of the other categories. (Okay, it's a little more precise than that, but, honestly, not much.)

> This is not to be mistaken for saying it doesn't exist or that it's all in someone's head - it's more just to say that if someone has depression, they have something that may deserve treatment and sensitivity, but that it's something that we still do not know exactly how to describe or diagnose, and so therefore we will just call it "depression" in the meantime.

I'd say that's pretty much on target. However, biology & biochemistry are proceeding forward at a breakneck pace these days. We do have some understanding of the causes for some kinds of depression, and this understanding seems to be improving significantly each year.

[1] https://en.wikipedia.org/wiki/Diagnostic_and_Statistical_Man...

There's DSM.

http://en.wikipedia.org/wiki/Diagnostic_and_Statistical_Manu...

Worth a look if you're interested in how mental disorders are diagnosed.

I studied psych in college a few years back and read about a variety of studies on how individuals with slight-moderate depression respond to certain stimuli. One of the most interesting studies (unrelated to the topic) had to deal with individuals looking into a mirror after failing a task. Individuals with >= slight depression would look themselves in the eyes, while happily ignorant individuals would avoid eye contact with themselves. They attributed this with a depressed person's desire to figure out what is wrong with themselves and internalize the failure, where as the happy people would avoid internalizing the failure.