<p>Disclosed is a prophylactic/therapeutic agent for depression, which comprises ferulic acid or a pharmaceutically acceptable salt thereof as an active ingredient. The prophylactic/therapeutic agent has few adverse side effects. The prophylactic/therapeutic agent is effective for a depression patient whose conditions are hardly ameliorated by conventional antidepressant agents. The prophylactic/therapeutic agent is also effective for preventing the recurrence of depression in a patient who receives the administration of an antidepressant agent at a reduced dose or for whom the administration of an antidepressant agent is discontinued.</p>
