This invention relates to substituted pyrimidinone and pyrimidithione derivatives that bind with high affifnity to CRF1 receptors, including human CRF1 receptors. This invention also relates to methods of using the compounds of the invention to treat a disorder or condition, the treatment of which can be effected or facilitated by antagonizing a CRF receptor, such as CNS disorders or diseases, particularly anxiety disorders, and depression and stress related disorders.