Unlike many other criminal offences, stalking is characterized by its repetition and persistence. The stalking victim is usually exposed to multiple forms of harassment, often involving threatening and traumatic incidents that are experienced as unpredictable and beyond the victim's control.

Research into the psychological effects of traumatic experiences such as natural disasters, war and sexual assault suggests that stress related symptoms develop more commonly in situations where the individual feels inescapably under threat over a protracted period, as occurs in stalking. Unpredictability is another important factor contributing to significant levels of stress. This is prominent in stalking situations, victims commonly experiencing a proliferation of uncertainties as the stalking progresses. Events involving a loss of control also appear to generate more persistent disquiet than circumstances where control could never be expected, as in the case of natural disasters. A stalking victim's feelings of helplessness can be reinforced by an unresponsive or ineffectual justice system. Often, their assumptions of living in a fair and safe society are shattered.

Trauma research has also looked at factors that protect victims from the development of disabling symptoms. Social support plays a central part, yet this is sometimes compromised in stalking victims. Stalking typically produces in the victim high levels of arousal and a pervasive distrust in others. Although such suspicion and caution may be entirely appropriate, they can also alienate victims from their usual sources of support, leading to social isolation.