A health coverage concept in which the scope and limitations of mental health services included in a health insurance plan are identical to those provided for medical health care services. Usually, the “parity” is restricted to disorders that are considered brain or neurobiologically based disorders such as schizophrenia, bipolar disorder, major depressive disorder, autistic disorder, panic disorder, and obsessive-compulsive disorder. Under the california mental health parity legislation (ab88), health plans must provide equal coverage for nine severe mental disorders: schizophrenia, schizoaffective disorder, obsessive-compulsive disorder, bipolar disorder, panic disorder, anorexia nervosa, bulimia nervosa, major depressive disorder, and pervasive developmental disorders. As neuroscience research into the causes of mental disorders becomes more advanced, the distinction between neurobiological disorders and those with a psychological basis will continue to diminish.