Mighty (Cheerful) Mouse
Scientists have bred a stain of mice that are permanently cheerful, by removing the TREK-1 gene, which realted to seratonin transmission in the brain. The mice "represent the first time depression has been eliminated through genetic alteration of an organism." The head researcher said the mice "acted as if they had been treated with antidepressants for at least three weeks" and speculated that this discovery could open up a new strain of drugs to treat depression.
But why think small, even if we are talking about mice? The debate about genetic engineering too often slips into squabbles about all those frivolous parents who will want blond, blue-eyed sons. Let's talk about this instead–what happens when parents have the option to genetically insure against depression?
Interesting tidbit: One way scientists test mice for depression is to dangle them by their tails. Mice that don't struggle are labeled "depressed."
See a Reason-sponsored debate on human genetic enhancement here.