Disclosed are methods, kits, and devices for diagnosing and treating psychiatric, disorders and the symptoms thereof. The methods, kits, and devices relate to identifying genetic markers that may be utilized to diagnose and/or prognose a patient and treat the diagnosed and/or prognosed patient by administering a drug the patient based on the genetic marker having been identified. Genetic markers identified in the methods may include HTR2C polymorphisms such as a polymorphism resulting in a Cys23Ser amino acid substitution, an rs3813929 (−759C/T) polymorphism, and an rs518147 (−697G/C) polymorphism).
