5-HT

1. A compound of the general formula (I) or a pharmaceutically acceptable salt thereof

wherein:

* denotes the (R) or (S) stereoisomer or any mixture thereof;

X is selected from the group consisting of I, CN, S—(C 1 -C 5 alkyl), S—(C 1 -C 5 fluoroalkyl), S—(C 2 -C 5 alkenyl), S—(C 2 -C 5 fluoroalkenyl), S—(C 2 -C 5 alkynyl), S—(C 2 -C 5 fluoroalkynyl), C 2 -C 5 alkyl, C 1 -C 5 fluoroalkyl, C 2 -C 5 alkenyl, C 2 -C 5 fluoroalkenyl, C 2 -C 5 alkynyl, and C 2 -C 5 fluoroalkynyl;

Y 1 and Y 2 are independently selected from the group consisting of O, S, C 1 -C 3 alkyl, C 1 -C 3 fluoroalkyl, and halogen;

R 1 is not present when Y 1 is C 1 -C 3 alkyl, C 1 -C 3 fluoroalkyl, or halogen;

R 2 is not present when Y 2 is C 1 -C 3 alkyl, C 1 -C 3 fluoroalkyl, or halogen;

when present, R 1 and R 2 are independently selected from the group consisting of C 1 -C 5 alkyl, C 1 -C 5 fluoroalkyl, C 2 -C 5 alkenyl, C 2 -C 5 fluoroalkenyl, C 2 -C 5 alkynyl, C 2 -C 5 fluoroalkynyl, C 3 -C 5 cycloalkyl, and C 3 -C 5 fluorocycloalkyl;

z denotes the number of R 3 groups and is an integer with a value of 0, 1, 2, or 3;

each R 3 is independently selected from the group consisting of F, C 1 -C 3 alkyl, C 1 -C 3 fluoroalkyl, C 2 -C 3 alkenyl, and C 1 -C 3 alkynyl; and

R 4 is H or CH 3 ;

with the proviso that at least one of Y 1 or Y 2 is selected as O or S.

2. The compound according to claim 1 , wherein X is selected from I, CN, S—(C 1 -C 3 alkyl), S—(C 1 -C 3 fluoroalkyl), C 2 -C 4 alkyl, C 1 -C 4 fluoroalkyl, ethynyl, fluoroethynyl or cyclopropyl.

3. The compound according to claim 1 , wherein X is selected from I, CN, S—(C 1 -C 3 alkyl), S—(C 1 -C 3 fluoroalkyl), C 2 -C 4 alkyl or C 1 -C 4 fluoroalkyl.

4. The compound according to claim 1 , wherein Y 1 and Y 2 are independently selected from the group consisting of O, S, halogen, and CH 3 .

5. The compound according to claim 1 , wherein at least one of Y 1 or Y 2 is S.

6. The compound according to claim 1 , wherein Y 1 and Y 2 are independently selected from O or S.

7. The compound according to claim 1 , wherein R 1 and R 2 are independently not present or are independently selected from the group consisting of C 1 -C 3 alkyl, C 1 -C 3 fluoroalkyl, and C 3 -C 5 cycloalkyl.

8. The compound according to claim 1 , wherein R 1 and R 2 are independently selected from the group consisting of C 1 -C 2 alkyl, C 1 -C 2 fluoroalkyl and cyclopropyl.

9. The compound according to claim 1 , wherein z is 0 or 1, and R 3 is selected from the group consisting of F, C 1 -C 2 alkyl, and C 1 -C 2 fluoroalkyl.

10. The compound according to claim 1 , wherein z is 0 or 1, and each R 3 is selected from the group consisting of F, CH 3 , and CF 3 .

11. The compound according to claim 1 , wherein * denotes (S) and R 4 is H.

12. The compound according to claim 1 , wherein the one or more R 3 groups are present at position 2, 3 or 6 in the piperidine.

13. A method of treating a depressive disorder, comprising:

administering an effective amount of a medicament comprising a compound according to claim 1 .

14. The method of claim 13 , wherein X is selected from the group consisting of I, CN, S—(C 1 -C 3 alkyl), S—(C 1 -C 3 fluoroalkyl), C 2 -C 4 alkyl, C 1 -C 4 fluoroalkyl, ethynyl, and fluoroethynyl.

15. The method of claim 13 , wherein X is selected from the group consisting of I, CN, S—(C 1 -C 3 alkyl), S—(C 1 -C 3 fluoroalkyl), C 2 -C 4 alkyl, and C 1 -C 4 fluoroalkyl.

16. The method of claim 13 , wherein Y 1 and Y 2 are independently selected from the group consisting of O, S, halogen, and CH 3 .

17. The method of claim 13 , wherein at least one of Y 1 and Y 2 is S.

18. The method of claim 13 , wherein Y 1 and Y 2 are independently selected from O or S.

19. The method of claim 13 , wherein R 1 and R 2 are independently not present or are independently selected from the group consisting of C 1 -C 3 alkyl, C 1 -C 3 fluoroalkyl, and C 3 -C 5 cycloalkyl.

20. The method of claim 13 , wherein R 1 and R 2 are selected from the group consisting of C 1 -C 2 alkyl, C 1 -C 2 fluoroalkyl and cyclopropyl.

21. The method of claim 13 , wherein z is 0 or 1, and R 3 is selected from the group consisting of F, C 1 -C 2 alkyl, and C 1 -C 2 fluoroalkyl.

22. The method of claim 13 , wherein z is 0 or 1, and each R 3 is independently selected from the group consisting of F, CH 3 , and CF 3 .

23. The method of claim 13 , wherein * denotes (S) and R 4 is H.

24. The method of claim 13 , wherein the one or more R 3 groups are present at position 2, 3 or 6 in the piperidine.

25. The method of claim 13 , wherein the of general formula (I) or a pharmaceutically acceptable salt thereof is administered in order to treat a depressive disorder selected from a list consisting of major depressive disorder (MDD) (also known as clinical depression, unipolar depression), treatment-resistant depression disorder (TRD), and severe treatment-resistant depression disorder.

26. The method of claim 13 , wherein the medicament further comprises a pharmaceutical acceptable carrier, optionally one or more excipients, and optionally other therapeutically active ingredients.

27. The method of claim 14 , wherein the medicament is administered at a regular interval in a dose range of 0.1 mg to 500 mg.

28. The compound according to claim 1 , wherein, when X=I, * represents the (S) stereoisomer.

29. The compound according to claim 1 , wherein X is selected from the group consisting of CN, S—(C 1 -C 5 alkyl), S—(C 1 -C 5 fluoroalkyl), S—(C 2 -C 5 alkenyl), S—(C 2 -C 5 fluoroalkenyl), S—(C 2 -C 5 alkynyl), S—(C 2 -C 5 fluoroalkynyl), C 2 -C 5 alkyl, C 1 -C 5 fluoroalkyl, C 2 -C 5 alkenyl, C 2 -C 5 fluoroalkenyl, C 2 -C 5 alkynyl, and C 2 -C 5 fluoroalkynyl.

30. The compound according to claim 1 , wherein X is selected from the group consisting of C 1 -C 4 fluoroalkyl.

31. The compound according to claim 1 , having the structure

or a pharmaceutically acceptable salt thereof.