Only older "typical" antipsychotics have been available in long-acting (depot) formulations. They are most frequently prescribed to enhance compliance and, to a lesser degree, for convenience, as the need for daily oral dosing is eliminated. The popularity of depot formulations has diminished since the introduction of highly effective oral atypical antipsychotics with vastly reduced side effects. However, long-acting injections remain an important treatment option for many patients with psychotic disorders, and the need to provide a safer, more effective depot formulation to this population is compelling. Accordingly, an "atypical" depot of olanzapine, which can be administered every 2 to 4 weeks, has been developed to enhance convenience and compliance with antipsychotic therapy.