Bothofthesestudiesuseddatafromsurveyswhosequestionsdeterminediftheparticipantexperienced a majordepressiveepisodeaccordingtotheDiagnosticandStatisticalManualofMentalDisorders.
A 2002 systematicreviewfoundthat 98% ofthosewhodiedfromsuicidehad a diagnosablementaldisorder, primarilydepression, whichaccountedfor 20 to 35% oftotaldeaths.