Objective: To find out whether chloroquine by itself can induce a mani
c syndrome and to study the course of illness in such cases. Method: A
l cases of manic episodes occurring in clear consciousness were scruti
nized and those occurring after the use of chloroquine were included i
n the study. One case seen by one of the authors in the community was
included. The cases were followed for variable periods. Result: Six ca
ses of chloroquine induced mania were identified of which two subtypes
could be delineated with heterogeneous course, variable severity and
difference in susceptibility of recurrence with rechallenge. Conclusio
n: It is concluded that chloroquine can cause secondary mania and it s
hould be used cautiously in the predisposed.