In erotomania, an individual has the fixed, unfounded belief that another person is deeply in love with him or her. The condition is usually regarded as delusional although a small number of cases may be non-delusional (Meloy, 1990). In some instances the imagined lover does not exist and is a ‘phantom’ (Seeman, 1978) but more generally is a real person who is unaware of the situation. He or she is often socially unattainable to the erotomanic sufferer and rarely has had close personal contact with the latter; and, in fact, frequently does not know he or she exists.

During the seventeenth century this ‘amor insanus’ was differentiated from nymphomania, which is the insatiable lust in a female for sexual intercourse, so its existence has been known for a very long time. As will be mentioned, until relatively recently erotomania was thought of as occurring almost exclusively in females, but is now known also to affect males.

Erotomania is frequently associated with the name of de Clérambault, a French psychiatrist who described the condition in some detail (de Clérambault, 1942). But in fact, as Segal (1989) has pointed out, Emil Kraepelin (1921) had already written about an erotomanic variety of paranoia much earlier and in this chapter it is his description of monodelusional erotomania which is emphasized.