Mental disorders are among the most elusive conditions in medicine and defy simple models, be they biological, psychological, social, or any simplistic admixture. In contrast to current classifications in other areas of medicine, those used in psychiatry, including the Diagnostic and Statistical Manual of Mental Disorders (DSM), rely on clinical manifestations (signs) and subjective reports (symptoms) rather than on the underlying causes and mechanisms.
Three landmark naturalistic studies funded by the National Institute of Mental Health (NIMH) provided some sobering statistics in this respect: psychiatric interventions are effective in less than 25% of patients presenting with an acute episode.17, 27 Diagnoses of mental health conditions are currently characterized by the following: