Evaluating psychotic patients' risk of violence: A practical guide
Investigate persecutory delusions and command hallucinations
When evaluating a patient’s risk of violence, the presence of psychosis is a crucial concern. Douglas et al1 found that psychosis was the most important predictor of violent behavior in an analysis of 204 studies examining the relationship between psychopathology and aggression. Clinicians need to be familiar with aspects of persecutory delusions and command auditory hallucinations that are associated with an increased risk of aggression because accurately assessing patients who are experiencing these 2 symptoms is an important part of a comprehensive violence risk assessment.
This article highlights the importance of investigating persecutory delusions and command auditory hallucinations when evaluating a psychotic patient’s risk for violence. We provide specific questions to ask to help gauge risk associated with these 2 symptoms.
Evaluating persecutory delusions
Do persecutory delusions increase the risk that a person will behave violently? Research examining delusions’ contribution to violent behavior does not provide a clear answer. Earlier studies suggested that persecutory delusions were associated with an increased risk of aggression.2 Delusions noted to increase the risk of violence were characterized by threat/control-override (TCO) symptoms. TCO symptoms are beliefs that one is being threatened (eg, being followed or poisoned) or is losing control to an external source (eg, one’s mind is dominated by forces beyond his or her control).3 Similarly, using data from the Epidemiologic Catchment Area surveys, Swanson et al4 found that patients who reported TCO symptoms were approximately twice as likely to engage in assaultive behavior compared with patients with other psychotic symptoms.
In contrast, the MacArthur Study of Mental Disorder and Violence5,6 showed that the presence of delusions did not predict higher rates of violence among recently discharged psychiatric patients. In particular, researchers did not find a relationship between the presence of TCO delusions and violent behavior. In a study comparing male criminal offenders with schizophrenia found not guilty by reason of insanity with matched non-offending schizophrenia patients, Stompe et al7 found no significant association between TCO symptoms and severity of violent behavior; prevalence of TCO symptoms did not differ between the 2 groups. However, nondelusional suspiciousness—such as misperceiving others’ behavior as indicating hostile intent—was associated with subsequent violence.6
Nederlof et al8 conducted a cross-sectional multicenter study to further examine whether TCO symptoms are related to aggressive behavior. Their study included 124 patients (88% men) who had paranoid schizophrenia (70%), “other forms” of schizophrenia (16%), schizoaffective disorder (3%), delusional disorder (1%), and psychosis not otherwise specified (10%). To measure TCO symptoms in a more detailed manner than in previous research, these researchers developed the Threat/Control-Override Questionnaire (TCOQ), a 14-item, self-report scale. The 7 threat items specific to the TCOQ are:8
- I am under the control of an external force that determines my actions.
- Other people have tried to poison me or to do me harm.
- Someone has deliberately tried to make me ill.
- Other people have been secretly plotting to ruin me.
- Someone has had evil intentions against me.
- I have the thought that I was being followed for a special reason.
- People have tried to drive me insane.
The 7 control-override items on the TCOQ are:8
- Other people control my way of movements.
- Other people can insert thoughts into my head.
- My thoughts are dominated by an external force.
- I have the feeling that other people can determine my thoughts.
- Other people can insert thoughts into my mind.
- I have the feeling that other people have control over me.
- My life is being determined by something or someone except for myself.
Nederlof et al8 determined that TCO symptoms were a significant correlate of aggression in their study sample. When the 2 domains of TCO symptoms were evaluated separately, only threat symptoms made a significant contribution to aggressive behavior. These researchers suggested that varying methods of measuring TCO symptoms may underlie previous studies’ seemingly contradictory findings.8 These recent findings indicate that the debate regarding the contribution of TCO symptoms, particularly threat symptoms, to future violence remains active.
Appelbaum et al9 used the MacArthur-Maudsley Delusions Assessment Schedule to examine the contribution of non-content-related delusional material to violence in interviews with 328 delusional hospitalized psychiatric patients. The 7 dimensions of the MacArthur-Maudsley Delusions Assessment Schedule are:
- Conviction—the degree of certainty about the delusional belief
- Negative affect—whether the delusional belief makes the patient unhappy, frightened, anxious, or angry
- Action—the extent to which the patient’s actions are motivated by the delusional belief
- Inaction—whether the patient has refrained from any action as a result of the delusional belief
- Preoccupation—the extent to which the patient indicates his or her thoughts focus exclusively on the delusion
- Pervasiveness—the degree to which the delusional belief penetrates all aspects of the patient’s experiences
- Fluidity—the degree to which the delusional belief changed frequently during the interview.
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 delusions2,10 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.
Evaluating persecutory delusions: 10 questions
Who or what do you believe wants to harm you?
How is this person attempting to harm you? (Ask about specific threat/control-override beliefs)
How certain are you that this is happening?
Is there anything that could convince you that this isn’t true?
How does your belief make you feel (eg, unhappy, frightened, anxious, or angry)?
Have you thought about any actions to take as a result of these beliefs? If so, what?
Have you taken any action as a result of your beliefs? If so, what specific actions?
Has your concern about being harmed stopped you from doing any action that you would normally do? Have you changed your routine in any way?
How much time do you spend thinking about this each day?
In what ways have these beliefs impacted your life?
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.
Evaluating command auditory hallucinations: 10 questions
What are the voices telling you to do?
Do you have any thoughts or beliefs that are associated with what you are hearing? If so, what are they?
Do you know the voice’s identity? If so, who is it?
How convinced are you that these voices are real?
Are these voices wishing you well or do you think that they wish you harm?
Have you done anything to help make the voices go away? If so, what?
Do you feel you have control of the voices or do you feel they control you?
Do you believe the voice is powerful?
How do the voices make you feel?
Have you ever done what the voice has told you to do? If so, describe what you did.
- MacArthur Research Network on Mental Health and the Law. The MacArthur Violence Risk Assessment Study.http://macarthur.virginia.edu/risk.html.
- Witt K, van Dorn R, Fazel S. Risk factors for violence in psychosis: systematic review and meta-regression analysis of 110 studies [published online February 13, 2013]. PLoS One. 2013;8(2):e55942. doi: 10.1371/journal.pone.0055942.
The authors report no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.
1. Douglas KS, Guy LS, Hart SD. Psychosis as a risk factor for violence to others: a meta-analysis. Psychol Bull. 2009;135(5):679-706.
2. Wessely S, Buchanan A, Reed A, et al. Acting on delusions. I: Prevalence. Br J Psychiatry. 1993;163:69-76.
3. Link BG, Stueve A. Evidence bearing on mental illness as a possible cause of violent behavior. Epidemiol Rev. 1995;17(1):172-181.
4. Swanson JW, Borum R, Swartz MS, et al. Psychotic symptoms and disorders and the risk of violent behaviour in the community. Crim Behav Ment Health. 1996;6(4):309-329.
5. MacArthur Research Network on Mental Health and the Law. The MacArthur Violence Risk Assessment Study. http://macarthur.virginia.edu/risk.html. Published April 2001. Accessed March 21 2013.
6. Monahan J, Steadman HJ, Silver E, et al. Rethinking risk assessment: the MacArthur study of mental disorder and violence. New York, NY: Oxford University Press, Inc.; 2001.
7. Stompe T, Ortwein-Swoboda G, Schanda H. Schizophrenia delusional symptoms, and violence: the threat/control override concept reexamined. Schizophr Bull. 2004;30(1):31-44.
8. Nederlof AF, Muris P, Hovens JE. Threat/control-override symptoms and emotional reactions to positive symptoms as correlates of aggressive behavior in psychotic patients. J Nerv Ment Dis. 2011;199(5):342-347.
9. Appelbaum PS, Robbins PC, Roth LH. Dimensional approach to delusions: comparison across types and diagnoses. Am J Psychiatry. 1999;156(12):1938-1943.
10. Buchanan A, Reed A, Wessely S, et al. Acting on delusions. II: The phenomenological correlates of acting on delusions. Br J Psychiatry. 1993;163:77-81.
11. Cheung P, Schweitzer I, Crowley K, et al. Violence in schizophrenia: role of hallucinations and delusions. Schizophr Res. 1997;26(2-3):181-190.
12. Freeman D, Garety PA, Kuipers E, et al. Acting on persecutory delusions: the importance of safety seeking. Behav Res Ther. 2007;45(1):89-99.
13. Shawyer F, MacKinnon A, Farhall J, et al. Command hallucinations and violence: implications for detention and treatment. Psychiatr Psychol Law. 2003;10(1):97-107.
14. Chadwick P, Birchwood M. The omnipotence of voices. A cognitive approach to auditory hallucinations. Br J Psychiatry. 1994;164(2):190-201.
15. Rudnick A. Relation between command hallucinations and dangerous behavior. J Am Acad Psychiatry Law. 1999;27(2):253-257.
16. McNiel DE, Eisner JP, Binder RL. The relationship between command hallucinations and violence. Psychiatr Serv. 2000;51(10):1288-1292.
17. Mackinnon A, Copolov DL, Trauer T. Factors associated with compliance and resistance to command hallucinations. J Nerv Ment Dis. 2004;192(5):357-362.
18. Junginger J. Predicting compliance with command hallucinations. Am J Psychiatry. 1990;147(2):245-247.
19. Erkwoh R, Willmes K, Eming-Erdmann A, et al. Command hallucinations: who obeys and who resists when? Psychopathology. 2002;35(5):272-279.
20. Beck-Sander A, Birchwood M, Chadwick P. Acting on command hallucinations: a cognitive approach. Br J Clin Psychol. 1997;36(pt 1):139-148.
21. Fox JRE, Gray NS, Lewis H. Factors determining compliance with command hallucinations with violent content: the role of social rank perceived power of the voice and voice malevolence. J Forens Psychiatry Psychol. 2004;15(3):511-531.