OBJECTIVE: This study determined if actors could portray depressed patients to establish the interrater reliability of raters using the Hamilton Depression Rating Scale (HDRS). METHOD: Actors portrayed depressed patients using scripts derived from HDRS assessments obtained at three points during treatment. Four experienced raters blindly viewed videotapes of two patients and two actors. They guessed if each interviewee was a patient or an actor and rated the certainty of their guesses. For each interview, they also rated the realism of the portrayal and completed the HDRS. RESULTS: Experienced raters could not distinguish actors and patients better than chance and were equally certain of their right and wrong guesses. Actors and patients received high scores on the realism of their portrayals. The HDRS scores of the actor-patient pairs were correlated. CONCLUSIONS: Actors can effectively portray depressed patients. Future studies will determine if actors can accurately portray patients with anxiety and psychosis.