 Although "melancholia" remained the dominant diagnostic term, "depression" gained increasing currency in medical treatises and was a synonym by the end of the century; German psychiatrist Emil Kraepelin may have been the first to use it as the overarching term, referring to different kinds of melancholia as "depressive states".English psychiatrist Henry Maudsley proposed an overarching category of "affective disorder".The influential system put forward by Kraepelin unified nearly all types of mood disorder into "manic–depressive insanity".