| Talbutal | sedative | 23rd ECDD (1987) - Critical review | 
      
                                                                      | Tapentadol | opioid | 35th ECDD (2012) - Pre-review,  36th ECDD (2014) – Pre-review | 
      
                                                                      | TEMAZEPAM | benzodiazepine | None 
 | 
      
                                                                      | TENAMFETAMINE | hallucinogen | None 
 | 
      
                                                                      | TENOCYCLIDINE | dissociative | None 
 | 
      
                                                                      | Tetrahydrocannabinol | cannabinoid | 40th ECDD (2018) – Pre-review | 
      
                                                                      | Tetrahydrocannabinol (including six isomers) | cannabinoid | 41st ECDD (2018) - Critical review | 
      
                                                                      | Tetrahydrofuranyl fentanyl | opioid | 39th ECDD (2017) - Critical review | 
      
                                                                      | TETRAZEPAM | benzodiazepine | None 
 | 
      
                                                                      | THEBACON | opioid | None 
 | 
      
                                                                      | THEBAINE | opioid | None 
 | 
      
                                                                      | Thialbarbital | sedative | 23rd ECDD (1987) - Critical review | 
      
                                                                      | Thiamylal sodium | sedative | 23rd ECDD (1987) - Critical review | 
      
                                                                      | Thiobutabarbital | sedative | 23rd ECDD (1987) - Critical review | 
      
                                                                      | Thiofentanyl | opioid | 26th ECDD (1989) - Critical review | 
      
                                                                      | Thiopental sodium | sedative | 23rd ECDD (1987) - Critical review | 
      
                                                                      | TILIDINE | opioid | None 
 | 
      
                                                                      | TMA | hallucinogen | None 
 | 
      
                                                                      | Tobacco | stimulant | 31st ECDD (1999) – Pre-review | 
      
                                                                      | Tramadol | opioid | 28th ECDD (1993) - Pre-review, 32nd ECDD (2001) - Pre-review, 33rd ECDD (2003) - Critical review, 34th ECDD (2006) - Pre-review, 36th ECDD (2014) - Pre-review, 39th ECDD (2017) – Pre-review , 41st ECDD (2018) - Critical review | 
      
                                                                      | Triazolam | benzodiazepine | 28th ECDD (1993) - Pre-review, 29th ECDD (1995) - Critical review | 
      
                                                                      | Triclofos | sedative | 24th ECDD (1988) - Critical review | 
      
                                                                      | Trihexyphenidyl | other | 29th ECDD (1995) – Pre-review | 
      
                                                                      | Trimeperidine | opioid | 7th ECDD (1957) - Critical review |