Evaluating psychotic patients' risk of violence: A practical guide

Patients with persecutory delusions had significantly higher scores on “action” and “negative affect” dimensions, indicating that those with persecutory delusions may be more likely to react in response to the dysphoric aspects of their symptoms.⁹ Subsequent research has demonstrated that patients who suffer from persecutory delusions and negative affect are more likely to act on their delusions^2,10 and to act violently¹¹ than patients without these symptoms.

When evaluating a patient who experiences persecutory delusions, inquire if he or she has employed “safety actions.” These are specific behaviors—such as avoiding a perceived persecutor or escaping a fearful situation—the individual has employed with the intention of minimizing a misperceived threat. In a study of 100 patients with persecutory delusions, 96% reported using safety behaviors in the past month.¹² In this study, individuals with a history of violence reported a greater use of safety behaviors.

Table 1 lists 10 questions to ask patients to explore persecutory delusions and associated risk factors for aggression.

Table 1

Evaluating persecutory delusions: 10 questions

Assessing auditory hallucinations

A careful inquiry about hallucinations can help determine whether their presence increases a patient’s risk of committing a violent act. Command hallucinations provide some type of directive to the patient. Approximately 50% of hallucinating psychiatric patients experience command hallucinations.¹³ Most command hallucinations are nonviolent, and patients are more likely to obey nonviolent instructions than violent commands.¹⁴

Research on factors associated with a patient acting on harmful command hallucinations has been mixed. In a review of 7 controlled studies, no study demonstrated a positive relationship between command hallucinations and violence, and 1 found an inverse relationship.¹⁵ In contrast, in a study of 103 psychiatric inpatients, McNiel et al¹⁶ found 30% reported having command hallucinations to harm others during the past year and 22% reported they complied with such commands. These researchers concluded that compared with those without command hallucinations, patients in their study who experienced command hallucinations to harm others were more than twice as likely to be violent.

Much of the literature examining the relationship between a patient’s actions and command hallucinations has examined the patient’s response to all command hallucinations, without delineating factors specific to violent commands. Seven factors are associated with acting on command hallucinations:¹³

• the presence of coexisting delusions¹⁷
• having delusions that relate to the hallucination¹⁸
• knowing the voice’s identity¹⁸
• believing the voices to be real¹⁹
• believing that the voices are benevolent²⁰
• having few coping strategies to deal with the voices¹⁷
• not feeling in control over the voices.²⁰

These factors also have been found to indicate increased compliance with acting on violent command hallucinations.^18,20 Studies that have examined compliance specific to harmful command hallucinations provide additional guidance when evaluating the patient’s risk of harm. Aspects relevant to increased compliance to violent command hallucinations include a belief that the voice is powerful,^13,21 a patient’s sense of personal superiority,²¹ a belief that command hallucinations benefit the patient,¹³ delusions that were congruent with the action described,¹³ and hallucinations that generate negative emotions such as anger, anxiety, and sadness.¹¹

Table 2 lists 10 questions to ask to further investigate general command auditory hallucinations and violent command auditory hallucinations.

Table 2

Evaluating command auditory hallucinations: 10 questions