Just on the face of this, it’s a cool idea, but it’s one of those things that didn’t even seem possible within a magnitude, so of course a few minutes of Googling was in order. Given the ecologically destructive effects of oil and coal burning, there would be no way that we would be doing it if solar were a reasonable option.

For the year 2000, the U.S. consumed about 3.8 trillion kilowatt-hours (kWh) of energy. You need about a 100 square feet of solar panel to provide 1 kWh. The amount of energy generated over the year depends heavily, of course, on where the panels are installed, but let’s assume that we’re going to put them in Texas, which means that we’ll get 1,800 kWh a year.

So, working this out means that we get:

3.8×10^12 kWh / 1800 kWh * 100 ft^2 / 5280^2 ft

… which is about 87 square miles on a side. Still enormously huge and enormously expensive, but just in checking the facts I’ve gone from “Oh, right, there’s no way” to something that is within a magnitude of reasonability. A magnitude, really, is just an engineering problem. There is no doubt that it would be totally unreasonable to make this many solar panels, there would be shortages in gallium arsenide and other components used for solar panels today. On the other hand, these figures are predicated on 10% efficiency, whereas we have experimental technologies that are getting in the range of 30%.

A number of relevant facts:

• Why were they testing on healthy people? The FDA requires such tests to study side effects, specifically, the metabolization of antidepressants^[3]
• Why would students participate in such studies? For the extra money — Traci Johnson, the student that killed herself, was getting paid $150/day + meals^[6], which is really good money for a student
• From the New York Times article: Robert Smith, a Lilly spokesman, said the company did not believe that duloxetine, the drug’s generic name, caused the suicide. “This drug has been studied in 9,000 patients, in depressed and nondepressed healthy people, and we have not been able to discern any signal between duloxetine and suicide or suicidal ideation,” Mr. Smith said.. I could not find the studies totaling up to 9,000; the one study that I did find^[8] gave a rate of 1 suicide attempt per 115 patient-years, which is not abnormally high for depressed patients. (I think that Easterbrook’s complaint about the suicide rate in test subjects (5/9,000) being too high is specious, as Corante points out; the question is, what is the general suicide rate among depressed patients? It works out to about 2% over the lifetime of the patient for patients that have been treated for depression^[11], but I have not yet found year-to-year rates by age group)
• Traci was one of 25 healthy students that were taking place in the study — given the small number of students, it makes the probability of some relationship to duloxetine that much higher — the average rate of suicide for people aged 15-19 is 9.7 per 100,000, with a 5:1 male:female ratio. This means that the chances of 1 out of 25 healthy students committing suicide, on the average, is 0.25%; this would be even lower if you took into account the different suicide rates in females vs. males. So, statistically, something looks really suspicious about this.
• Antidepressants have been, in many cases, counterindicated for anybody under 18. The theory is that developing brains react to the drugs differently than adults. Traci Johnson was 19 at the time of the study

The Indianopolis Star claims that the suicide rate for patients was only 0.097 percent, whereas the rate for SSRI antidepressents is 1.5 percent. This figure is suspiciously low (it’s two magnitudes lower!) and I suspect a division error by the paper; it doesn’t match the results in the Journal of Clinical Psychiatry^[8], which gives a suicide attempt rate just under 1%^[9].

Financial implications. Lilly had total revenues of 12.5B in 2003^[5], and estimates for duloxetine ranged as high as $2 billion in 2008^[3]. Lilly’s patent on Prozac (fluoxetine hydrochloride) is gone and they are getting quite a bit of competition from generics, so they really want a new, patented medicine in their array of drugs.

Conclusion. I think it will all boil down to one thing: Dr. Joe Glenmullen, a clinical instructor of psychiatry at Harvard Medical School, said that “patients taking antidepressants are most vulnerable to suicidal thoughts three to 10 days after they cease the medication.”^[3] (also mentioned in the New York Times article^[6]). If this is true^[7], then the question is: was Lilly conscientious in making sure that students taken off the drug were tracked? If not, look for a major negligence law suit.