The need for better treatments is undeniable. Mental illness is now the leading cause of healthy life lost in the developed world, and is rising rapidly in developing countries [WHO, 2006]. Existing antipsychotics fail to address the cognitive symptoms of schizophrenia, such as executive dysfunction, which have been increasingly recognized as highly disabling [Hyman and Fenton, 2003]. Available antidepressants act slowly and still fail to bring about remission in more than half of patients with depression. Lithium remains highly effective for some people with bipolar disorder, but most do not enjoy sufficient benefit from lithium or a range of more recently developed mood stabilizers. PTSD and other combat-related mental illness have reached crisis levels among recent veterans and yet no medication has proven effective. Suicide, usually related to mental illness, is a major cause of death, with a rate that is now twice the homicide rate and even surpasses traffic fatalities in the US [Centers for Disease Control; http://www.cdc.gov/nchs/data/nvsr/nvsr60/nvsr60_04.pdf).
