Schizophrenia, Delusional Symptoms, and Violence: The Threat/Control-Override Concept Reexamined

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1 Schizophrenia, Delusional Symptoms, and Violence: The Threat/Control-Override Concept Reexamined by Thomas Stompe, Qerhard Ortwein'Swoboda, and Hans Schanda Abstract In 1994 Link and Stueve identified a number of symptoms called threat/control-override (TCO) symptoms that were significantly more than others related to violence. This was confirmed by some, but not all, following studies. The contradictory results could be due to remarkable differences in sample compositions, sources used, and definitions and periods of recorded violence, but they are mainly due to problems defining the TCO symptoms. To reexamine the validity of the TCO concept from an exclusively psychopathological position, we compared in a retrospective design a sample of male offenders with schizophrenia not guilty by reason of insanity (n = 119) with a matched sample of nonoffending schizophrenia patients (n = 105). We could find no significant differences regarding the prevalence of TCO symptoms hi the two groups during the course of illness. The only statistically significant discriminating factors were social origin and substance abuse. Yet, taking into account the severity of offenses, TCO symptoms emerged as being associated with severe violence. This effect is primarily attributable to the comparatively unspecific threat symptoms. Control-override, to be seen as more or less typical for schizophrenia, showed no significant association with the severity of violent behavior. Keywords: Schizophrenia, violence, threat/control-override symptoms. Schizophrenia Bulletin, 30(l):31^44, Regardless of the much more important influence of general criminogenic factors such as (antisocial) personality disorders and substance abuse, newer studies with different designs are confirming a modest but significant link between mental illness and criminal/violent behavior (Lindqvist and Allebeck 1990; Swanson et al. 1990; Hodgins 1992; Link et al. 1992; Wessely et al. 1994; Hodgins et al. 1996; Modestin and Ammann 1996; Stueve and Link 1997; Tiihonen et al. 1997; RasSnen et al. 1998; Brennan et al. 2000a, 2000fc; Mullen et al. 2000jTAn overrepresentation of schizophrenia patients is repeatedly reported mainly among the most severe forms of violence (Petursson and Gudjonsson 1981; Lindqvist 1986; Gottlieb et al. 1987; Eronen et al. 1996a, 1996*, 1996c, 1997; Wallace et al. 1998), confirming the prejudices of the general population against these patients. The search for reliable predictive factors for future violence is a matter of special interest (Steadman et al. 1993; Monahan and Steadman 1994; Monahan and Appelbaum 2000; Steadman and Silver 2000). Clinical diagnoses as more or less stable (actuarial) predictors can in fact provide (at least partly) statistically significant results, yet they suffer from a lack of specificity. Dynamic psychopathological factors such as delusional/psychotic symptoms seem to have a higher predictive value and have always been associated with violent behavior (B6ker and Hafner 1973; Taylor 1985; Krakowski et al. 1986; Link et al. 1992). Some years ago, Link and Stueve identified among the range of delusional symptoms a few that were significantly more frequently than others related to violence. As these symptoms describe a patient's feeling of being "gravely threatened by someone who intends to cause harm" (p. 143) and of an override of self-control through external forces, they were called threat/control-override (TCO) symptoms (Link and Stueve 1994). These findings were corroborated in general by several other studies (Swanson et al. 1996, 1997; Link et al. 1998), and meanwhile the TCO concept has found its way into the literature dealing with risk assessment and risk management (e.g., Bjtfrkly 2000; Cooke 2000). However, scepticism was expressed by Mullen (1997) regarding the rates of thought insertion and feelings of external control in the nonpsychotic Link and Send reprint requests to Dr. T. Stompe, Justizanstalt GSllersdorf, Gflllersdorf 17, 2013 Austria; thomas.stompe@chello.at. 31

2 Schizophrenia Bulletin, Vol. 30, No. 1, 2004 T. Stompe et al. Stueve community sample (1994). He pointed out that "whatever is being measured it is unlikely to be the relatively uncommon passivity phenomena, at least not in the form traditionally recognised" (Mullen 1997, p. 7). And, in fact, the first prospective investigation based on data from five face-to-face interviews within 1 year in more than 1,000 patients (MacArthur Violence Risk Assessment Study) (Appelbaum et al. 2000) was not able to confirm the earlier positive results. Moreover, Appelbaum et al. found that "body/mind control delusions... displayed a negative relationship to the incidence of violence" (2000, p. 568), at least during the first two followup assessments in their sample. Their effort to duplicate the designs of the earlier studies (retrospective selfreports) as closely as possible initially led to significant results, but these were eliminated after controlling for anger and impulsivity measures. These contradictory results may be caused not least by methodological problems. Table 1 shows that apart from the differences in the sample compositions the instruments used, the definitions of violence and TCO symptoms, and the periods and procedures of recording were remarkably divergent: the lay-administered Psychiatric Epidemiology Research Interview (PERI) and the Diagnostic Interview Schedule (Link and Stueve 1994; Swanson et al. 1996, 1997; Link et al. 1998), DSM-1II-R diagnoses based on hospital charts and mental health center records (Swanson et al. 1997) or face-to-face interviews by clinically trained research staff (Appelbaum et al. 2000), the psychiatrist-administered Schedule for Affective Disorders and Schizophrenia (SADS) (Link et al. 1998), and expert-administered special instruments such as the MacArthur-Maudsley Delusions Assessment Schedule, the Novaco Anger Scale, and the Barratt Impulsiveness Scale (Appelbaum et al. 2000). The periods of several components of recorded violence were past month, past year, and past 5 years (Link and Stueve 1994); past year and whole adult life period (Swanson et al. 1996) and additionally past 5 years and following 18 months (Swanson et al. 1997); past 5 years (Link et al. 1998); and in the only prospective study during several followup intervals (10 weeks each) (Appelbaum et al. 2000). All but Appelbaum et al. (and partly Swanson et al. 1997) were dealing with self-reported aggression. The periods of recorded TCO symptoms were past month/past year (Link and Stueve 1994), past year and adult life period (Swanson et al. 1996), past year (Link et al. 1998), and every 10 weeks (Appelbaum et al. 2000). From the position of a clinical psychiatrist, the several definitions of the TCO symptoms are of special interest. In Link and Stueve (1994), thought withdrawal and movement control were not counted as TCO symptoms unlike in Swanson et al. (1996). In Swanson et al. (1997), two different formulations were applied the Link and Stueve (1994) definition for the Triangle Mental Health Survey (TMHS) subsample using the corresponding items from the PERI, and the Swanson et al. (1996) definition for the Epidemiologic Catchment Area (ECA) subsample. Probably the most precise definition of psychopathology was that of Appelbaum et al. (2000), who used the MacArthur-Maudsley Delusions Assessment Schedule, an adaptation of the Maudsley Assessment of Delusions Schedule as an expert rating (Appelbaum et al. 1999) and, additionally, patients' self-reports. Given that (in concordance with DSM definitions) especially "transitivistic" passivity phenomena are primarily found in patients with schizophrenia and related disorders, we tried to reexamine the validity of the TCO concept from an exclusively clinical/psychopathological standpoint, comparing a sample of offenders with schizophrenia found to be not guilty by reason of insanity (NGRI) with a matched sample of nonoffending schizophrenia patients regarding the frequency of TCO symptoms and their possible association with violent behavior. Methods According to Austrian law, persons who have committed a severe offense (i.e., under threat of a penalty of more than 1 year of imprisonment) in causal connection with a mental disorder and who are found NGRI by the courts are exculpated and have to be treated under restriction order for an indefinite period of time, most of them in the Justizanstalt Gollersdorf, Austria's central high-security institution for male mentally ill offenders (Schanda et al. 2000). Patients of the Justizanstalt Gollersdorf with a clinical diagnosis of schizophrenia who had been delusional at any time during their illness were interviewed by means of the SADS: Lifetime Version (SADS-L) (Spitzer and Endicott 1977). Those who met DSM-IV criteria for schizophrenia (American Psychiatric Association 1994) (n = 119) were included in the study and further checked with the SADS-L as to substance abuse. Additionally, the delusional symptomatology was documented by means of a semistructured questionnaire (Fragebogen zur Erfassung psychotischer Symptome [FPS]), developed for transcultural studies on the psychotic symptomatology of schizophrenia patients (Stompe and Ortwein-Swoboda, unpublished manuscript, 1999). As the earlier studies on TCO symptoms primarily investigated violent behavior in general without reference to legal categories, we decided to use for reason of better comparability the classification according to Taylor (1985) targeting primarily the severity of the violent acts (in our case, the index offenses leading to detention in the high-security institution). 32

3 o E. P o a E. a o I s; o_ Table 1. Sample characteristics, study designs, diagnostic instruments, definitions, and periods of recorded violence and TCO symptoms In previous studies on TCO symptoms Sample characteristics, study design Relevant diagnostic instruments Aggression (sources, period of recording) TCO symptoms (definition, period of recording) Link and Stueve (1994) 232 patients (various diagnoses), 521 community residents Retrospective PERI (lay administered) Self-reported Hitting (past mo, past yr) Fighting (past 5 yrs) Weapon use (past 5 yrs) 1. Thought/mind control 2. Thought insertion 3. Feeling that other people wish to do harm Past mo, past yr (50% of sample each) Swanson et al. (1996) 10,066 community residents (ECAdata) Retrospective DIS (lay administered) Self-reported Self-reported (TMHS also hospital charts, court records) Hitting, injuring partner or TMHS: any violent acts child, physical fight weapon toward others (following 18 use, physical fight while mos, past 5 yrs) drinking ECA: see Swanson et al. (1996) Past yr, adult life period 1. Thought/movement control 2. Thought insertion/withdrawal 3. Belief that others are plotting, trying to hurt or poison 4. Belief that others are following Swanson et al. (1997) TMHS (n= 169) plus ECA (n = 129) pooled sample of persons with psychiatric disorders (various diagnoses) Retrospective (TMHS partly prospective) TMHS: DSM-llt-R (hospital charts, mental health center records) PERI ECA: DIS TMHS: see Link and Stueve (1994) (period of recording unknown) ECA: see Swanson et al. (1996) Link et al. (1998) Community sample (n = 2,678) Retrospective PERI (lay administered) SADS (psychiatrist administered) Self-reported Physical fight, weapon use Past 5 yrs Past yr, adult life period Past yr 1. Thought/mind control 2. Thought insertion 3. Feeling that others wish to do harm 4. Persecutory delusions 5. Delusions of control Appelbaum et al. (2000) 1,136 discharged hospital inpatients, various diagnoses, 5 followup evaluations during 1 yr Prospective DSM-ill-R checklist, MacArthur-Maudsley Delusions Assessment Schedule, Novaco Anger Scale, Barratt Impulsiveness Scale (research interviewers, consultant psychiatrists) Self-reported, collaterals, arrest records Batteries resulting in physical injury or involving use of a weapon, sexual assaults, threats made with a weapon in hand During each followup period (10 wkseach) 1. Belief of being under external control (actions, thoughts) 2. Thought insertion 3. Thought withdrawal 4. Belief of being hypnotized, being under magic performance, or being hit by X-rays or laser beams 5. Belief that people are spying 6. Belief that people are following 7. Belief of being secretly tested, experimented on 8. Belief that someone is ploting, trying to hurt, poison During each followup period Note. OIS» Diagnostic Interview Schedule; ECA = Epidemiologic Catchment Area; PERI = Psychiatric Epidemiology Research Interview; SADS = Schedule for Affective Disorders and Schizophrenia; TCO >= threat/control-override; TMHS - Triangle Mental Health Survey.

4 Schizophrenia Bulletin, Vol. 30, No. 1, 2004 T. Stompe et al. Taylor defines "minimal" (la verbally aggressive, lb carrying a weapon which was not used, lc minimal damage to property when this was accidental) and "moderate" violence (2a actual bodily harm, 2b sexual offense under force, 2c using an offensive weapon but without causing injury, 2d damage to property when this was the main intent) as "low violence"; "moderately serious" (3a grievous bodily harm, 3b> damage to property when this was extensive and could have threatened life) and "serious" violence (4a victim died, 4b life actually endangered and victim detained in hospital more than 24 hours) as "high violence." As a certain degree of dangerousness is the legal prerequisite for the detention of a mentally ill offender (see above), Taylor's categories lb, lc, and 2a did not apply to our sample. So we equated our legal categories severe threat and compulsion with Taylor's item "verbally aggressive" (la), sexual offenses without physical injury of the victim with "sexual offense under force" (2b), robbery and severe compulsion using a weapon with "using an offensive weapon but without causing injury" (2c), and severe damage to property (including a part of the cases of arson) with "damage to property when this was the main intent" (2d) and classified them as "low violence." Severe bodily injury was equated with "grievous bodily harm" (3a), arson under certain (especially dangerous) circumstances with "damage to property when this was extensive and could have threatened life" (3b), and murder and attempted murder with Taylor's categories serious violence with (4a) and without (4b) death of the victim, all classified as "high violence." Without a doubt, objections could be raised to classify sexual offenses under force as equal to, for example, severe verbal aggressiveness or actual bodily harm. But the ranking of Taylor is committed not to legal or moral standards as criteria for severity but only to the amount of violence. Even so, if a sexual assault included the bodily injury of the victim, it had to be rated as high violence. As our sample included only four cases of sexual assault, none of them with severe bodily injury, we decided to follow the Taylor classification (1985). Forty-seven offenders had committed low-severity offenses, and 68 high-severity offenses; in four cases a definite classification was not possible because of the incompatibility with our legal definitions. The social levels of origin were documented by means of the Soziale Selbsteinstufung, a scale measuring the prestige of the patients' fathers' professions (Kleining and Moore 1968). This scale is based on a survey in a representative sample of 48,312 persons in Germany who were asked to choose one of 36 options to identify their professions and their fathers' professions. The ratings were validated by sociologists and placed in nine subgroups, arranged in three major classes (upper, middle, lower). The scale has often been used in epidemiologic and clinical investigations (e.g., Schepank 1990; Stompe et al. 2000). The control sample was drawn from the consecutive admissions to the Psychiatric University Clinic of Vienna and an affiliated rehabilitation center for chronic schizophrenia patients. Patients with previous convictions were excluded. The files of all (also former) inpatient treatments were checked for every clue of violence not officially prosecuted. Moreover, the patients were asked for former violent behavior, although not as systematically as in the investigations cited in table 1. If there was a clear indication of (usually minor) forms of violence in the descriptions of the admission procedures or in the collateral reports documented in the files, the patient was excluded from the study. Finally, our control sample consisted of 105 male schizophrenia patients matched within certain ranges for age, duration of illness, and schizophrenia subtypes. The diagnostic assessment of the control group was identical with that of the offender group. The SADS-L and FPS ratings were carried out by two experienced psychiatrists (T.S. and G.O.-S.) and were based on face-to-face interviews and the files from previous hospitalizations. This allowed the documentation of TCO symptoms present at any time during the illness. The period of recruitment for both groups was 1994 to Following the psychopathologically oriented German tradition (Kraepelin ; Jaspers 1913; Schneider 1939), the FPS is subdivided into three sections (delusions, Schneiderian first rank symptoms, hallucinations). So our definition of TCO symptoms is in contrast to the definitions used by Link and Stueve (1994), Link et al. (1998), and Swanson et al. (1996, 1997) reduced to clear persecutory delusions and to the typical (schizophrenic) "passivity phenomena" (Jaspers 1913) addressed by Mullen (1997). Appendix 1 shows the translation of those FPS items corresponding with the TCO symptoms. By threat we understand the delusional belief of imminent danger caused by others. In concordance with Swanson et al. (1997) we discriminate between the delusional idea of being vitally threatened by physical aggression or poisoning and the delusion of being followed by one or more persons. By control-override we understand the loss of control over one's own thoughts, feelings, movements, and actions in connection with the belief that an external power has taken control over these functions. We followed Kurt Schneider's definition insofar as the psychotic influence on volition has to be experienced directly by the patient Under "made volition," Schneider (1939) summarized the first rank symptoms of made motion, made action, made thoughts, and made emotions. He described 34

5 Schizophrenia, Delusional Symptoms, and Violence Schizophrenia Bulletin, Vol. 30, No. 1, 2004 thought insertion and thought withdrawal as belonging to the experiences of being influenced. We ascertained them separately and then united both under the term "thought shifting." So, control-override consists of the two symptom clusters "made volition" and "thought shifting." To scrutinize the interrater reliability for the TCO symptoms, the interviews of 48 patients were rated independently by the two psychiatrists (T.S. and G.O.-S.). In these cases Cohen's kappa for the single items was 0.75 to 0.98 with the exception of made emotions. For the diagnosis of schizophrenia according to the SADS-L, Cohen's kappa was In a first step we assessed the possible association of substance abuse, social origin, and TCO symptoms with violence by means of univariate statistics (2-tailed chisquare test). Subsequently, stepwise forward logistic regression was used to examine the risk of violence with and without TCO symptoms and the generally accepted criminogenic variables social level of origin and substance-related disorders. Model 1 is based on the single independent variable social origin, model 2 adds substance-related disorders, and models 3 and 4 TCO symptoms, controlling for the prior variables, thus leading from the general to the particular. The results are presented as odds ratios. All data analyses were carried out with the SPSS version 6.1 for Windows (Buhl and Zofel 1995). Results Table 2 shows the sociodemographic and basic clinical data of both offender and nonoffender groups. There are no significant differences regarding age, age at onset, duration of illness, and schizophrenia subtypes (DSM-IV). However, the overrepresentation of schizophrenia patients with substance-related disorders (with the exception of nonalcohol substance abuse, dependence) is highly significant in the offender group, which also originates more often from lower social levels. Table 3 displays the prevalence of TCO symptoms in the two groups. One can see that TCO symptoms could be registered very frequently in a 7-year course. Threat (feeling of being poisoned, hurt, or followed) was rated far Table 2. Age, age at onset, duration of Illness, schizophrenia subtypes, substance-related disorders (DSM-tV), and social class of origin In offending and nonoffending male schizophrenia patients Offenders (n = 119) Nonoffenders (n=105) Significance Mean ± SD Mean ± SD Age 29.9 ± ns 1 Age at onset 22.5 ± ns 1 Duration of illness ns 1 n(%) n(%) Chi-square Schizophrenia subtypes Disorganized Catatonic Paranoid Residual Undifferentiated 6 (5.0) 11 (9.2) 88 (73.9) 11 (9.2) 3 (2.5) 6 (5.7) 8 (7.6) 82(78.1) 7 (6.7) 2(1.9) Additional substance-related disorders Alcohol abuse, dependence Nonalcohol abuse, dependence Polysubstance-related disorder 64 (53.8) 21 (17.6) 21 (17.6) 22(18.5) 29 (27.6) 8 (7.6) 20(19.0) 1 (1.0) 15.72"* 4.98* *** Social class of origin 2 Upper Middle Lower 3 (2.5) 56(47.1) 60 (50.4) 13(12.4) 54(51.4) 38 (36.2) 8.18" * Note. ns " nonsignificant; SD = standard deviation. 1 ftest. 2 Prestige of the profession of patients 1 fathers according to Kieining and Moore (1968). * p < 0.05; " p < 0.01; *** p <

6 Schizophrenia Bulletin, Vol. 30, No. 1, 2004 T. Stompe et al. more often than was control-override. Within the controloverride cluster, those symptoms summarized under thought shifting occurred more often than experiences of external influence on volition. Neither on the level of single symptoms nor on that of symptom clusters could we find any differences between offenders and nonoffenders. These results were confirmed by a multivariate procedure (table 4): A stepwise forward logistic regression model based on only the social class of origin (model 1) led to a statistically significant result. Adding substancerelated disorders (model 2) improved the statistical significance, while the inclusion of TCO symptoms (model 3) was not able to ameliorate the statistical significance of the model chi-square. A completely different situation emerges when highand low-violence offenders are compared. Table 5 shows that the general criminogenic factors (substance-related disorders and social class of origin) have no impact on the discrimination between high and low violence. But, in contrast, residual and disorganized schizophrenia subtypes are overrepresented in low, paranoid subtype in high-violence offenders, although the statistical significances are not as pronounced as in the differences regarding substance abuse in the comparison of offenders and nonoffenders (table 2). Also, regarding TCO symptoms there were differences between the two offender groups (table 6). Again, threat was the symptom cluster registered most frequently. Table 3. Prevalence of TCO symptoms during entire course of illness in offending and nonoffending male schizophrenia patients Offenders (n = 119) Nonoffenders (n = 105) n(%) n(%) Chl-square Threat Being poisoned, hurt Being followed 100(84.0) 59 (49.6) 70 (58.8) 81 (77.1) 48 (45.7) 62 (59.0) Control override Made volition Made motions Made actions Made thoughts Made emotions 50 (42.0) 28 (23.5) 17(14.3) 19(16.0) 7 (5.9) 9 (7.6) 51 (48.6) 27 (25.7) 17(16.2) 15(14.3) 9 (8.6) 4 (3.8) Thought shifting Thought insertion Thought withdrawal 42 (35.3) 40 (33.6) 9 (7.6) 40(38.1) 37 (35.2) 14(13.3) Threat and/or control-override symptoms 105(88.2) 95 (90.5) 0.29 Table 4. Stepwise forward logistic regression models for risk of violence In male schizophrenia patients Offenders (n= 119) vs. nonoffenders (n = 105) Model chi-square Risk factors Social origin Substance-related disorders TCO Symptoms Model 1 Social origin OR (95% Cl) 1.93" ( ) 8.74" Model 2 + Substance-related disorders OR (95% Cl) 1.83*( ) 2.94"* ( ) 22.66"" Model 3 + TCO symptoms OR (95% Cl) 1.83* ( ) 2.94*** ( ) 22.66**** Note. Cl - confidence interval; OR = odds ratio; TCO = threat/control-override. Parameter significance tests based on WakJ chi-square testwfthc#= 1. * p < 0.05; " p < 0.01; *** p < 0.001; *"* p <

7 Schizophrenia, Delusional Symptoms, and Violence Schizophrenia Bulletin, Vol. 30, No. 1,2004 Table 5. Age, age at onset, duration of Illness, schizophrenia subtypes, substance-related disorders (DSM-iV), and social class of origin In high- and low-violence male schizophrenia offenders 1 Age Age at onset Duration of illness Schizophrenia subtypes Disorganized Catatonic Paranoid Residual Undifferentiated Additional substance-related disorders Alcohol abuse, dependence Nonalcohol abuse, dependence Polysubstance-related disorder Social class of origin 3 Upper Middle Lower High violence Low violence (n = 68) (n = 47) Significance II Mean ± SD 30.2 ±8.1 Note. ns = nonsignificant. 1 Severity of offense rated according to Taylor (1985), total n = 115, In 4 cases definite classifications not possible because of incompatibility wtth legal definitions. 2 nest 3 Prestige of the profession of patients' fathers according to Kieining and Moore (1968). * p < ± ±7.1 n(%) 1 (1.5) 9(13.2) 55 (80.9) 3 (4.4) 34 (50.0) 10(14.7) 14(20.6) 10(14.7) 1(1.5) 33 (48.5) Mean ± SD 29.4 ± ± ± 7.0 Table 6. Prevalence of TCO symptoms during entire course of illness in high- and low-violence male schizophrenia offenders 1 Threat Being poisoned, hurt Being followed Control override Made volition Made motions Made actions Made thoughts Made emotions Thought shifting Thought insertion Thought withdrawal Threat and/or controloverride symptoms High violence (n = 68),n(%) 64(94.1) 39 (57.4) 42(61.8) 30(44.1) 17(25.0) 9(13.2) 11 (16.2) 4 (5.9) 9(13.2) 27 (39.7) 26 (38.2) 6 (8.8) 66(97.1) n(%) 5(10.6) 2 (4.3) 30 (63.8) 8(17.0) 2 (4.3) 27 (57.4) 10(21.3) 7 (14.9) 10(21.3) 2 (4.3) 23 (48.9) 22 (46.8) Low violence (n = 47),n(%) 33 (70.2) 19(40.4) 25 (53.2) 19(40.4) 10(21.3) 7 (14.9) 7 (14.9) 3 (6.4) 4 (8.5) 14(29.8) 13(27.7) 3 (6.4) 36 (76.6) m? m? ns> Chl-square 4.72* * 5.11* Chl-square 12.03*" "* Note. TCO = threat/control-override. 1 Severity of offense rated according to Taylor (1985), total n = 115, in 4 cases definite classification not possible because of incompatibility wtth legal definitions. *"p<

8 Schizophrenia Bulletin, Vol. 30, No. 1, 2004 T. Stompe ct al. But despite the fact that also 70.2 percent of the low-violence offenders exhibited threat symptoms during their illness, the differences between the low- and the high-violence groups reached statistical significance (p < 0.001). In contrast, control-override symptoms, taken separately or as a group, showed no association with the severity of the offense. In a stepwise forward logistic regression analysis, neither social origin (model 1) nor substance-related disorders (model 2) were able to separate the high- from the low-violence group (table 7). Only the inclusion of TCO symptoms in the logistic regression (model 3) led to a statistically significant result. TCO symptoms were significantly related to high violence. In another series of stepwise forward logistic regression procedures, the influence of threat and control-override symptoms was analyzed separately (table 8). As the models 1 and 2 are identical with those in table 7, only the new models 3 (+ control-override symptoms) and 4 (+ threat symptoms) are presented. One can see that the association between TCO symptoms and high violence in table 7 has to be ascribed primarily to the threat component, while control-override has no statistically significant effect. Discussion The search for reliable predictor variables for future violence of mentally ill subjects is one of the most important topics of forensic psychiatry, not only because of the special public interest, and the prejudices against and the stigmatization of psychiatric patients, but also because of the consequences on general mental health care (e.g., civil commitment laws) (Miller 1993; Beck 1996; Beck and Wencel 1998; Schanda 1999, 2001). Apart from general criminogenic factors, delusional symptomatology has always been considered a major trigger of violent behavior (B5ker and Hafner 1973; Rofrnan et al. 1980; Taylor 1985). So the TCO concept introduced by Link and Stueve (1994) appeared to be plausible at first glance in concordance with common clinical knowledge and was seen as an important step forward in the improvement of risk assessment in mental patients. The results of Link and Stueve (1994) were confirmed by a number of studies (Swanson et al. 1996, 1997; Link et al. 1998), with the exception of the only prospective one (Appelbaum et al. 2000) in which Mullen's (1997) principal objections regarding the definitions of TCO symptoms most likely have been taken into account (table 1). Therefore, it seemed necessary to reinvestigate the position of the TCO symptoms (in a strict and narrow psychopathological definition; appendix 1) in schizophrenia patients who committed a violent act leading to longterm treatment in a forensic institution by comparison with a control group of schizophrenia patients without a history of aggressive behavior. The offender and the nonoffender groups did not differ in age, age at onset, duration of illness, and schizophrenia subtypes (table 2). Yet, as was to be expected, general criminogenic factors such as lower social class of origin (see Edwards et al. 1988; Farrington 1990; Wessely and Taylor 1991; Farrington and West 1993; Heads and Taylor 1997; Hiday 1997; Stueve and Link 1997; Swartz et al. 1998; Kennedy et al. 1999) and substance-related disorders (see Eronen et al. 1996a; Monahan 1997; RasSnen et al. 1998; Scott et al. 1998; Swartz et al. 1998; Wallace et al. 1998; Citrome and Volavka 1999; George and Krystal 2000; Mullen et al. 2000) could be found more frequently in the offender group, confirming the knowledge of an association between low social class of Table 7. Stepwise forward logistic regression models for risk of high-violence offending In male schizophrenia offenders High- (n = 68) vs. lowviolence (n» 47) offenders 1 Model chi-square Risk factors Social origin Substance-related disorders TCO symptoms Model 1 Social origin OR (95% Cl) Model 2 + Substance-related disorders OR (95% Cl) Model 3 + TCO symptoms OR (95% Cl) 10.08" ( ) 11.96*" Note. Cl = confidence interval; OR = odds ratio; TCO = threat/corttroj-override. Parameter significance tests based on WakJ chi-square testwtth<#= 1. 1 Severity of offense rated according to Taylor (1985), total n = 115, in 4 cases definite classification not possible because of incompatibility with legal definitions. " p < 0.01 ;"* p <

9 Schizophrenia, Delusional Symptoms, and Violence Schizophrenia Bulletin, Vol. 30, No. 1, 2004 Table 8. Step wise forward logistic regression models for risk of high-violence offending In male schizophrenia offenders with separate Inclusion of threat and control-override symptoms High- (n = 68) vs. lowviolence (n = 47) offenders 2 Model chi-square Model 3 1 Social origin + Substance-related disorders + control-override Model 4 1 symptoms + Threat symptoms Risk factors OR (95% Cl) OR (95% Cl) Social origin Substance-related disorders Control-override symptoms Threat symptoms " ( ) 12.11*" Atore. Cl = confidence Interval; OR - odds ratio. Parameter significance tests based on WakJ chi-square test with df= 1. 1 Models 1 and 2 are Identical to those in table 7. 2 Seventy of offense rated according to Taylor (1985), total n - 115, In 4 cases definite classification not possible because of incompatibility with legal definitions. ** p < 0.01 ;*" p < origin and violent/criminal behavior the latter in concordance with sociological theories regarding the suppression of aggressive behavior by education in higher social classes (Elias 1976; Bourdieu 1988). In table 3, one can see that TCO symptoms could be registered in both groups very frequently during a 7-year course. Link and Stueve (1994), Link et al. (1998), and Swanson et al. (1996, 1997) do not offer any information about the occurrence of TCO symptoms within the several diagnostic subgroups. This is also the case in Appelbaum et al. (2000). But, after combining the original sample description (Steadman et al. 1998) with the number of TCO symptoms at the time of index hospitalization (Appelbaum et al. 1999), one can draw the conclusion that in the MacArthur sample 84.1 percent of the schizophrenia patients with suspected delusions (or 51.1% of all schizophrenia patients) had persecutory delusions in the weeks before index admission; the rates for body/mind control were 75.4 percent and 45.8 percent, respectively. So, the frequency of TCO symptoms is comparable to that in our sample despite the different periods of registration (mean more than 7 years vs. 10 weeks). However, there were no significant differences in the occurrence of TCO symptoms in the offender and the nonoffender groups (88.2% vs. 90.5%). This is confirmed by a multivariate procedure that showed the importance of sociodemographic factors and substance abuse for the discrimination between offenders and nonoffenders (table 4). As it is known from the literature that the severity of a violent act is positively correlated with the increasing influence of illness-related factors (see Lindqvist and Allebeck 1990; Swanson et al. 1990; Link et al. 1992; Hodgins et al vs. Gottlieb et al. 1987; Eronen et al. 1996a, 1996*, 1996c; see also Wallace et al. 1998), we subdivided our offender sample into those with high- and low-severity offenses according to Taylor (1985). And, in fact, the paranoid subtype is moderately but significantly overrepresented in the high-violence group, confirming the aforementioned general knowledge (Bdker and Hafner 1973; Eronen et al. 1996c), while the disorganized and the residual subtypes showed an association with low violence (table 5). Sociodemographic factors and substance abuse were not able to differentiate between the high- and the low-violence groups. In contrast to the lack of significance regarding the differentiation of offenders and nonoffenders, TCO symptoms showed a statistically significant association with high violence (table 6). While control-override symptoms were not able to discriminate between the high-and the low-violence groups, threat symptoms were registered significantly more often in the severely violent group. This was confirmed by multivariate statistics (table 7). Only the inclusion of TCO symptoms (model 3) was able to ameliorate the model chi-square and to define the high-violence group. Nevertheless, it must be kept in mind that TCO symptoms were present also in 76.6 percent of the low-violence offenders (table 6), thus indicating a high false-positive rate. The remarkably different frequencies of threat and control-override symptoms and the fact that only threat symptoms but not control-override symptoms were significantly overrepresented in the high-violence offender group (table 6) suggest that there should be a separate investigation of the influence of threat and control-over- 39

10 Schizophrenia Bulletin, Vol. 30, No. 1, 2004 T. Stompe et al. ride (table 8) by all means in concordance with Link et al. (1998). But, while Link et al. (1998) found both threat and control-override to be independently associated with violent behavior, our data confirmed such an effect for only the threat component. However, the significance of our data is limited because of a number of methodological limitations, which also apply to the studies presented in table 1, with the exception of Appelbaum et al. (2000). First, the study design is retrospective, which in general means a reduction of validity. But one has to take into account that prospective studies on violent behavior over longer periods of time with repeated patient interviews suffer from the unavoidable bias that the investigation of the problem per se is changing the outcome (Schanda and Taylor 2001). Second, the longer the periods of registration of violence and TCO symptoms, the more questionable the causal connection between symptoms and violence (see Taylor and Hodgins 1994). Third, as proven by Steadman et al. (1998), agency records represent only part of the total amount of violent behavior. Like all other studies on TCO symptoms, with the exception of Appelbaum et al. (2000) and partly Swanson et al. (1997), our study did not include a personal interview of collaterals. Despite the fact that our control patients were asked about violent behavior in a nonstandardized way and all hospital files were checked for any indication of violence not officially prosecuted, we cannot be certain that our "nonviolent" controls have not been violent in the past. But one has to remember that Europe's crime rates, cases solved, and nonalcohol substance abuse are quite different from those of the United States especially regarding more severe forms of violence. The U.S. homicide rate, for instance, is four times that of the United Kingdom (Eronen et al )- The same holds true for the number of cases solved (Eronen et al. 1996*, 1997) and the extent of illicit substance abuse (Eronen et al. 1996c). So the possibility of a major bias seems rather low in our sample. Fourth, the role of impulsivity was not sufficiently considerea 1 quite apart from the fact that impulsivity in connection with acute psychotic symptomatology cannot be automatically equalized with personality-based impulsivity (Stompe and Ortwein-Swoboda 2000). Fifth, the varying influence of the level of social functioning of a patient on symptom-caused violence (Swanson et al. 1998) and the role of social networks (Estroff et al. 1994) have not been taken into account. But, apart from all the methodological problems, the crucial question for the assessment of the validity of the TCO symptoms for the prediction of violent behavior seems to be their different meanings (for investigators and patients), which points to the principal problem of data collection. Appelbaum et al. (2000) concluded that the "reliance on subject self-reports of delusional symptoms may result in mislabelling as delusions other phenomena that can contribute to violence" (p. 566), but it is an investigator's job to make the best possible attribution of a phenomenon. The "unbiased" registration of a "symptom" suggests an increase in reliability but introduces a new bias that leads to a decrease in validity by neglecting the central problem: whether the patient and the investigator understand the question the same way (see also the results of Klosterkotter et al. 1994). In the case of lay interviews, the problem may be increased by deficits in the interviewers' knowledge of subtle psychopathological phenomena such as feelings of external control. So, especially for the assessment of CO symptoms, it is necessary to assess their presence more precisely by asking additional questions (appendix 1). This problem is illustrated by Link et al. (1998). From their data one can calculate that comparable items were registered in the same sample with remarkably different frequencies depending on whether the SADS or the PERI was used: SADS "persecutory delusions" 0.4 percent vs. PERI "people wished to do harm very/fairly often" 7.3 percent (plus "sometimes/almost never" 53.8%); SADS "delusions of control" 1.4 percent vs. PERI "mind dominated by external forces very/fairly often" 2.2 percent (plus "sometimes/almost never" 16.8%), adding to the latter the PERI item "thoughts put in head that were not the patient's own" 4 percent ("very/fairly often") and 35.3 percent ("sometimes/almost never"). Obviously, the layadministered PERI is documenting in contrast to the psychiatrist-administered SADS the perception of a hostile environment in general without the obligatory presence of severe psychopathology. This confirms the statement of Appelbaum et al. (2000), who were able to replicate earlier findings "only by including a large number of presumptively nondelusional symptoms under the threat/controloverride rubric" (p. 571). Taking all this into account, one has to doubt whether the meanings of the TCO symptom definitions in the Link and Swanson papers are really comparable with those in the Appelbaum paper (table 1) or with our own. In any case, it seems necessary to question a positive as well as a negative answer of a patient, to ask for examples, and to insist on precise descriptions (appendix 1). Regarding the insinuated "exceptional dangerousness" of schizophrenia patients, we have concluded that control-override symptoms if seen in concordance with the definitions for schizophrenia disorders and affective disorders with mood-incongruent features in DSM-IV (APA 1994, pp. 275, 378, 381) are not an outstanding source of violence. Moreover, from the 40

11 Schizophrenia, Delusional Symptoms, and Violence Schizophrenia Bulletin, Vol. 30, No. 1, 2004 position of a clinical psychiatrist, one has to consider that these symptoms are often rather volatile and brief and can be experienced by the patient also as neutral or positive (Stompe and Ortwein-Swoboda 2000). In contrast, delusional threat is for a patient an exclusively negative (ominous, dangerous) phenomenon. But threat is, compared to control-override, relatively unspecific and occurs not only as "a generally suspicious attitude toward others" (Appelbaum et al. 2000, p. 571) but also as a clear delusional symptom in schizophrenia as well as in affective, organic, substance-related, and personality disorders. Conclusion Our results confirm the importance of general factors such as substance abuse and social origin for the violent behavior of schizophrenia patients. The TCO symptoms in a narrow, clinical definition were not associated with violence in general, yet they turned out to be an indicator of the severity of an offense. This effect is primarily due to the comparatively unspecific threat symptoms, whereas control-override symptoms at least in our definition typical for schizophrenia showed no significant association with severe violence. Future research is needed to investigate the complex interactions between psychotic symptoms, underlying affect, impulsivity, social level of functioning, social networks, and violence. References American Psychiatric Association. DSM-FV: Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: APA, Appelbaum, P.S.; Clark Robbins, P.; and Monahan, J. Violence and delusion: Data from the MacArthur Violence Risk Assessment Study. American Journal of Psychiatry, 157: , Appelbaum, P.S.; Clark Robbins, P.; and Roth, L.H. Dimensional approach to delusions: Comparison across types and diagnoses. American Journal of Psychiatry, 156: , Beck, J.C. Forensic psychiatry in the USA and U.K.: A clinician's review. Criminal Behaviour and Mental Health, 6:11-27, Beck, J.C, and Wencel, H. Violent crime and axis I psychopathology. In: Skodol, A., ed. Psychopathology and Violent Crime. Washington, DC: American Psychiatric Press, pp Bjorkly, S. High-risk factors for violence. Emerging evidence and its relevance to effective treatment and prevention of violence on psychiatric wards. In: Hodgins, S., ed. Violence Among the Mentally III. Dordrecht, The Netherlands: Kluwer, pp Boker, W., and Hafher, H. Gewalttaten Geistesgestdrter. New York, NY: Springer, Bourdieu, P. Die feinen Unterschiede. Kritik der gesellschaftlichen Urteilskraft. 2nd ed. Frankfurt/Main, Germany: Suhrkamp, Brennan, P.; Grekin, E.; and Vanman, E. Major mental disorders and crime in the community. A focus on patient populations and cohort investigations. In: Hodgins, S., ed. Violence Among the Mentally 111. Dordrecht, The Netherlands: Kluwer, 2000a. pp Brennan, P.A.; Mednick, S.A.; and Hodgins, S. Major mental disorders and criminal violence in a Danish birth cohort. Archives of General Psychiatry, 57: , BOhl, A. and Zofel, P. SPSSfUr Windows. Version nd ed. Bonn, Germany: Addison-Wesley, pp Citrome, L., and Volavka, J. Schizophrenia: Violence and comorbidity. Current Opinion in Psychiatry, 12:47-51, Cooke, D.J. Major mental disorder and violence in correctional settings. Size, specificity, and implications for practice. In: Hodgins, S., ed. Violence Among the Mentally III. Dordrecht, The Netherlands: Kluwer, pp Edwards, J.G.; Jones, D.; Reid, W.H.; and Chu, Ch.-Ch. Physical assaults in a psychiatric unit of a general hospital. American Journal of Psychiatry, 145: , Elias, N. Ober den Prozess der Zivilisation: Soziogenetische und psychogenetische Unterschiede. Frankfurt/Main, Germany: Suhrkamp, Eronen, M.; Hakola, P.; and Tiihonen, J. Factors associated with homicide recidivism in a 13-year sample of homicide offenders in Finland. Psychiatric Services, 47: , 1996a. Eronen, M.; Hakola, P.; and Tiihonen, J. Mental disorders and homicidal behavior in Finland. Archives of General Psychiatry, 53: ,1996fc. Eronen, M.; Tiihonen, J.; and Hakola, P. Schizophrenia and homicidal behavior. Schizophrenia Bulletin, 22(l):83-89, 1996c. Eronen, M.; Tiihonen, J.; and Hakola, P. Psychiatric disorders and violent behavior. International Journal of Psychiatry in Clinical Practice, 1: , Estroff, S.E.; Zimmer, C; Lachicotte, W.S.; and Benoit, J. The influence of social networks and social support on violence by persons with serious mental illness. Hospital and Community Psychiatry, 45: ,

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