The original GBD study covered unipolar depression, bipolar disorder, panic disorder, obsessive-compulsive disorder, posttraumatic stress disorder, and illicit drug use. The new study will include these disorders plus eating disorders (anorexia and bulimia), dysthymia, generalized anxiety disorder, agoraphobia, social phobia, separation anxiety disorder, pervasive developmental disorders (autism and Asperger's disorder), attention-deficit disorder, and conduct disorder. In the original GBD study, cannabis dependence was not considered, and a limited definition that focused on heroin dependence formed the basis of illicit drug use estimates. The new study will include estimates of burden attributable to heroin and other opiates, cocaine, amphetamines, and cannabis. Estimates for alcohol abuse and dependence will be revised.