Psychologists often group individuals who stalk into two categories: psychotic and nonpsychotic. Some stalkers may have pre-existing psychotic disorders such as delusional disorder, schizoaffective disorder, or schizophrenia. However, most stalkers are nonpsychotic and may exhibit disorders or neuroses such as major depression, adjustment disorder, or substance dependence, as well as a variety of personality disorders (such as antisocial, borderline, or narcissistic). The nonpsychotic stalkers’ pursuit of victims is primarily angry, vindictive, focused, often including projection of blame, obsession, dependency, minimization, denial, and jealousy. Conversely, only 10% of stalkers had an erotomanic delusional disorder.
In “A Study of Stalkers” Mullen et al. (2000) identified five types of stalkers:
- Rejected stalkers follow their victims in order to reverse, correct, or avenge a rejection (e.g. divorce, separation, termination).
- Resentful stalkers make a vendetta because of a sense of grievance against the victims – motivated mainly by the desire to frighten and distress the victim.
- Intimacy seekers seek to establish an intimate, loving relationship with their victim. Such stalkers often believe that the victim is a long-sought-after soul mate, and they were ‘meant’ to be together.
- Incompetent suitors, despite poor social or courting skills, have a fixation, or in some cases, a sense of entitlement to an intimate relationship with those who have attracted their amorous interest. Their victims are most often already in a dating relationship with someone else.
- Predatory stalkers spy on the victim in order to prepare and plan an attack – often sexual – on the victim.