Some common psychiatric diagnosis codes are 296.31 (F33.0), major depressive disorder, recurrent episode, mild; 300.23 (F40.10), social anxiety disorder or social phobia; 309.28 (F43.23), adjustment disorder with mixed anxiety and depressed mood; and 300.02 (F41.1), generalized anxiety disorder.
The codes associated with psychiatric diagnoses are actually the ICD-9 codes and ICD-10 codes used for insurance billing. One example is 307.1 (F50.01), anorexia nervosa, restricting type. The number 307.1 is the ICD-9 code for anorexia nervosa. The letter-number combination F50.1 is the ICD-10 code for anorexia nervosa, restricting type. If the combination was F50.02, it would specify anorexia nervosa, binge eating/purging type.