- Significant acute suicide risk, defined as follows: suicide attempt within the previous 6 months that required medical treatment; or ≥ 2 suicide attempts in the past 12 months; or has a clear-cut plan for suicide and states that they cannot guarantee that they will call their regular psychiatrist or the investigator if the impulse to implement the plan becomes substantial during the study; or in the investigator's opinion, is likely to attempt suicide within the next 6 months.