The present invention provides novel inhibitors of the enzyme D-amino acid oxidase. The compounds of the invention are useful for treating or preventing diseases and/or condition, wherein modulation of D-serine levels, and/or its oxidative products, is effective in ameliorating symptoms. The invention further provides methods of enhancing learning, memory and/or cognition. For example, the invention provides methods for treating or preventing loss of memory and/or cognition associated with neurodegenerative diseases, such as Alzheimer's disease. The invention further provides methods for preventing loss of neuronal function characteristic of neurodegenerative diseases. In addition, methods are provided for the treatment or prevention of neuropsychiatric diseases (e.g., schizophrenia) and for the treatment or prevention of pain and ataxia.