6,7-Dihydro-5H-cyclopenta[b]pyridine and 5,6,7,8-tetrahydroquinoline compounds of Formula (I), including salts, hydrates and solvates thereof, that act as 5-HT.sub.2 receptor ligands and their uses in the treatment of diseases linked to the activation of 5-HT.sub.2c receptors are described herein. ##STR00001##