Mirtazepine is an atypical antidepressant. It also reduces anxiety. The main side effect is excessive sedation due to its antihistaminic action. However if the complaint is only insomnia (sleeplessness) & not anxiety or depression then Zaleplon, a non - benzodiazepine is preferable. This is more effective in insomnia and does not result in day time sedation and dizziness. Adult dose is 10mg at bed time.