There's a danger in tabbing back to the comments page after the third paragraph. A few paragraphs lower, you would have seen this:

>So he and his colleagues turned to the scientific literature for ideas. A handful of American studies had suggested that lithium might prolong the effect of sleep deprivation, so they investigated that. They found that 65% of patients taking lithium showed a sustained response to sleep deprivation when assessed after three months, compared to just 10% of those not taking the drug.