People who are known to have died by suicide from barbiturate overdose include Stefan Zweig,[11][12] Gillian Bennett,[13] Charles Boyer, Ruan Lingyu, Victor Folke Nelson,[14][15] Dalida,[16][17] Jeannine "The Singing Nun" Deckers, Felix Hausdorff, Abbie Hoffman, Phyllis Hyman, Marilyn Monroe, Cesare Pavese, C. P. Ramanujam, George Sanders, Carole Landis, Jean Seberg, Lupe Vélez and the members of the Heaven's Gate cult.

Others who have died as a result of barbiturate overdose include Pier Angeli, Brian Epstein, Judy Garland, Jimi Hendrix, Inger Stevens, Dinah Washington, Ellen Wilkinson, and Alan Wilson; in some cases these have been speculated to be suicides as well.

Those who died of a combination of barbiturates and other drugs include Rainer Werner Fassbinder, Dorothy Kilgallen, Malcolm Lowry, Edie Sedgwick and Kenneth Williams.

Maurice Chevalier attempted suicide in March 1971 by swallowing a large amount of barbiturates and slitting his wrists.

The differential diagnosis should include intoxication by other substances with sedative effects, such as benzodiazepines, anticonvulsants (carbamazepine), alcohols (ethanol, ethylene glycol, methanol), opioids, carbon monoxide, sleep aids, and gamma-Hydroxybutyric acid (GHB).

Natural disease that can result in disorientation may be in the differential, including hypoglycemia and myxedema coma.