Although monotherapy is generally recommended as the treatment of choice, treatment resistance of patients with psychosis, cognitive, mood and anxiety disorders represents a significant clinical problem. In this context, augmentation and combination strategies are commonly employed to address this problem. Although multiple medication use common in psychiatric practice, reasons, efficacy and safety for polypharmacy, and augmentative strategies have remained unclear. It remains unclear if there is an evidence base to support polypharmacy. Furthermore, excessive and inappropriate use of psychotropic medications has been recognized as a public health problem. This volume is the first comprehensive, clinically oriented, reference on the multiple medication use to treat psychotic, cognitive, mood and anxiety disorders.