Abstract
Unplanned acts of suicidal behavior involve little preparation or forethought whereas planned acts may be carefully conceived and implemented. Planned acts are associated with greater depression, hopelessness, and lethality, but there are meager data on other factors associated with planning. The prevention of planned and unplanned acts may require different strategies, but in either case improved knowledge is required to tailor prevention efforts. Improved knowledge can be facilitated by the acceleration of validation studies on assessments of planning, taking steps to avoid the conflation of assessments of planning with measurements of psychopathology such as impulsivity, and the use of controlled research designs.