ANNALS OF CLINICAL PSYCHIATRY 2010;22(2):113-120
Donald W. Black, MD
Department of Psychiatry
University of Iowa Roy J. and Lucille A. Carver College of Medicine
Iowa Department of Corrections
Iowa Medical and Classification Center Oakdale, IA, USA
Tracy Gunter, MD
Department of Psychiatry and Neurology St. Louis University School of Medicine St. Louis, MO, USA
Peggy Loveless, PhD Jeff Allen, PhD
Department of Psychiatry
University of Iowa Roy J. and Lucille A. Carver College of Medicine
Iowa City, IA, USA
Bruce Sieleni, MD
Department of Psychiatry
University of Iowa Roy J. and Lucille A. Carver College of Medicine
Iowa Department of Corrections
Iowa Medical and Classification Center Oakdale, IA, USA
BACKGROUND: We determined the frequency of antisocial personality disorder (ASPD) in offenders. We examined demographic characteris- tics, psychiatric comorbidity, and quality of life in those with and without ASPD. We also looked at the subset with attention-deficit/hyperactivity disorder (ADHD).
METHODS: A random sample of 320 newly incarcerated offenders was assessed using the Mini International Neuropsychiatric Interview (MINI), the 36-item Short Form Health Survey (SF-36), and the Level of Service Inventory–Revised (LSI-R).
RESULTS: ASPD was present in 113 subjects (35.3%). There was no gender- based prevalence difference. Offenders with ASPD were younger, had a higher suicide risk, and had higher rates of mood, anxiety, substance use, psychotic, somatoform disorders, borderline personality disorder, and ADHD. Quality of life was worse, and their LSI-R scores were higher, indi- cating a greater risk for recidivism. A subanalysis showed that offenders with ASPD who also had ADHD had a higher suicide risk, higher rates of comorbid disorders, and worse mental health functioning.
CONCLUSION: ASPD is relatively common among both male and female inmates and is associated with comorbid disorders, high suicide risk, and impaired quality of life. Those with comorbid ADHD were more impaired than those without ADHD. ASPD occurs frequently in prison popula- tions and is nearly as common in women as in men. These study findings should contribute to discussions of appropriate and innovative treatment of ASPD in correctional settings.
Antisocial personality disorder (ASPD) is characterized by a pervasive pattern of socially irresponsible, exploit- ative, and guiltless behavior. ASPD has a prevalence of between 3.9% and 5.8% in men and 0.5% and 1.9% in women in the US general population.1-3 The disorder is associated with significant psychosocial impairment, depression, substance misuse, and domestic violence; suicide is an all too common outcome.4-6 Family and marital relationships are frequently disrupted in persons with ASPD, and health care utilization is excessive.7,8 The prevalence of ASPD is higher in correctional than in psy- chiatric settings.9-15 In prison, offenders with ASPD can present a considerable management problem because of their irritability, aggression, disregard for the rights of others, and lack of remorse.16,17
We recently assessed the prevalence of ASPD and other psychiatric disorders in a group of offenders newly committed to the Iowa Department of Correc- tions (IDOC). This was part of a larger prevalence survey already reported.18 Subjects were assessed with DSM-IV criteria using standardized instruments of known reli- ability. We expected to see ASPD at higher frequencies in men than in women, and that offenders with ASPD would have poorer quality of life, and higher rates of psy- chiatric comorbidity than offenders without ASPD. We further expected that antisocial offenders with comor- bid attention-deficit/hyperactivity disorder (ADHD) would fare even worse. We have already reported on offenders with borderline personality disorder (BPD)19 and those with ADHD.20
Subjects were randomly selected for participation from the daily census roster of incoming offenders newly committed to the IDOC and undergoing intake assess- ment at the Iowa Medical and Classification Center (IMCC) in Oakdale, Iowa. IMCC serves as a reception facility for the IDOC. All newly committed offenders are admitted for essential intake and reception activi- ties, including a health screen, basic orientation to Iowa’s correctional system, institutional assignment, and initiation of the IDOC’s central offender record. The process lasts 4 to 6 weeks, after which offenders are assigned to 1 of 9 correctional facilities through- out Iowa to serve their sentence. The sample does not include persons who had violated probation, those requiring special programming (eg, close super- vision, segregation, seclusion), or those requiring maximum security placement. Violent offenders and those requiring segregation or maximum security place- ment were excluded because they could not be easily moved into the testing area. Stays in special program- ming units were generally brief so that most inmates were generally unavailable for the testing. Women were purposely oversampled so that their percentage in the study was approximately twice that in the Iowa prison population.
Interviewing was conducted at IMCC by trained rat- ers. All subjects gave written, informed consent accord- ing to procedures approved by the University of Iowa Institutional Review Board and were compensated. The study was conducted under a Certificate of Confidenti- ality and in compliance with Office of Human Research Protections regulations regarding research with prison- ers.21 These regulations help to ensure that the rights of offenders are protected and that research procedures are not coercive.
Demographic data, including age, sex, race/eth- nicity, education, income, and marital status, were obtained along with legal/criminal variables of inter- est. Offenders were administered the MINI-Plus,22 a fully structured instrument that assesses the pres- ence of DSM-IV23 mood disorders, anxiety disorders, somatoform disorders, substance use disorders, psy- chotic disorders, eating disorders, conduct disorder, ASPD, ADHD, and adjustment disorder. A summary score is calculated to indicate suicide risk. The ASPD section involves 2 areas of inquiry. In the first, sub- jects are asked about 6 specific problematic child- hood misbehaviors; if ≥2 are endorsed, then subjects are asked about 6 antisocial behaviors since age 15; ≥3 are required for the diagnosis. The BPD module of the Structured Interview for DSM-IV Personality (SIDP- IV)24 was used to assess the presence of BPD and its traits. (This screen was added after the study was under way and was administered to a subset of 220 offend- ers.) The Medical Outcomes Study 36-item Short Form Health Survey (SF-36)25,26 was used to assess functional status. Finally, subjects were administered the Level of Service Inventory–Revised (LSI-R),27 used in correc- tional settings to gather data on social/demographic variables and criminal history. The instrument also provides a measure of the primary risk factors that con- tribute to the development of lifetime adjustment prob- lems and is used to predict recidivism.
The Pearson chi-square test (or the Fisher’s exact test when the expected cell counts were too small) was used for comparison of categorical variables. P values <.05 were considered statistically significant.
A total of 322 subjects were recruited, and 320 (264 men, 56 women) completed the assessment protocol. A total of 113 offenders (35.3%) met criteria for ASPD. The percentage of men with ASPD was greater than that for women (37.1% and 26.8%, respectively), but the differ- ence was not significant. Associated demographic char- acteristics of the sample are shown in TABLE 1. Offend- ers with ASPD were mean age 29.3 years, and most were Caucasian. ASPD status was not related to race/ ethnicity, education, marital status, or current criminal offense. The ASPD group was much more likely to be considered at risk for suicide based on a scale embed- ded in the MINI-Plus.
TABLE 2 compares antisocial and nonantisocial offenders with respect to selected LSI-R items. Because offenders with ASPD were more likely to be men, we calculated adjusted odds ratios (with confidence inter- vals and P values) by fitting a logistic regression model for each LSI-R item (treated as a dichotomous out- come) with ASPD status, gender, age, and race/ethnic- ity as covariates. Subjects with ASPD were more likely to report prior mental health treatment (80.5% in ASPD group, 66.2% in non-ASPD group); the odds of having prior mental health treatment were 2.4 times higher for the ASDP group (95% confidence interval, 1.4 to 4.3). From TABLE 2, we also see that antisocial subjects were more likely to report ≥3 prior convictions, to have been punished for misconduct (in prison), and to have been fired before incarceration.
TABLE 3 compares current and lifetime psychiatric diagnoses between the 2 groups and shows statistically significant differences in the percentage of subjects with mood, anxiety, substance use, psychotic, conduct, any MINI, and somatoform disorders; ADHD; and BPD. Of note, there was considerable overlap between ASPD and BPD; 44% of 84 offenders with ASPD who received the BPD screen also met criteria for BPD. Psychoses were frequent in both groups, although most were related to substances (n = 47) or to a medical condition (n = 1).
TABLE 4 presents comparisons of the 2 groups on semicontinuous measures of interest, including the LSI-R total score and SF-36 scales. We report the adjusted dif- ference (D) in the groups’ means for each measure. The adjusted differences were derived by fitting multiple linear regression models with each measure (LSI-R total or SF-36) as the outcome, and gender, age, and race/ethnic- ity as covariates. The LSI-R total scores were higher for the ASPD subjects, suggesting a greater likelihood of recidi- vism. The SF-36 scale scores were consistently lower for the ASPD group with the exception of physical function- ing. Variables indicating emotional well-being were par- ticularly affected, including role limitations due to emo- tional health, mental health, and the summary scale for mental health; social functioning was also worse in the group with ASPD.
We conducted a subanalysis comparing 37 antisocial offenders with ADHD and 75 without; thus, 33% of anti- social offenders had comorbid ADHD. (One subject was omitted from the analysis because the data for an ADHD diagnosis were incomplete and group assignment was not possible.) There were no differences in demograph- ics, education, type of current offense, selected items from the LSI-R, or the LSI-R score itself. Offenders with ADHD were more likely to have high suicide risk scores (62% vs 28%, respectively; P < .001). A comparison of MINI data shows that the subset with ADHD were sig- nificantly more likely to meet criteria for major depres- sion (62% to 19%; P < .001), bipolar disorder (78% to 59%;P < .04), other mood disorder (24% to 7%; P = .008), any mood disorder (97% to 65%; P < .001), panic disorder (24% to 5%; P = .009), body dysmorphic disorder (14% to 1%; P = .015), and any somatoform disor- der (18% to 5%; P = .039). They also had significantly worse SF-36 mental health subscores (P < .001) and worse mental health summary scores (P =.011). (Tables are not shown.)
More than 35% of offenders assessed for this study met criteria for ASPD. The rate of ASPD is higher than in our pilot study (19%),28 despite using the same diagnostic instrument at the same facility, but the finding could be due to the larger sample and more consistent administration of the ear regression models with each measure (LSI-R total or SF-36) as the outcome, and gender, age, and race/ethnic- ity as covariates. The LSI-R total scores were higher for the ASPD subjects, suggesting a greater likelihood of recidi- vism. The SF-36 scale scores were consistently lower for the ASPD group with the exception of physical function- ing. Variables indicating emotional well-being were par- ticularly affected, including role limitations due to emo- tional health, mental health, and the summary scale for mental health; social functioning was also worse in the group with ASPD.
MINI-Plus. Importantly, there was no significant differ- ence in its prevalence between men (37%) and women (27%). Although ASPD mainly occurs in men in the general population, it appears that its frequency among incarcerated women approaches that of men. The fact that so many women met criteria for ASPD is a strong indicator that the disorder needs to be included in the differential diagnosis in prison settings, particularly when the presenting complaints involve irresponsibil- ity, aggression, or deceitfulness.
Although the overall rate appears high, this rate falls in the midrange of what others have reported. It should not be interpreted as a prevalence estimate among all offenders but, rather, those newly commit- ted to the IDOC who were physically and psychiatrically stable at the time of the interview and on a regular secu- rity level. Repeat offenders, those on special program- ming, persons violating probation, maximum security new offenders, and offenders not sentenced to prison (ie, probationers) were not included. Thus, the true rate of ASPD could be much higher.
Rates of ASPD among incarcerated offenders have varied from 11% to 78% among men and 12% to 65% among women, depending on the sample size, particu- lar prison population sampled, and assessment method used.9-15 Blackburn and Coid15 reported in a study from England that 62% of 164 violent male offenders met criteria for ASPD. Jordan et al12 assessed 805 women entering prison in North Carolina and reported that 12% were antisocial, whereas Zlotnick14 reported that 40% of 85 women offenders incar- cerated in Rhode Island met criteria for ASPD. Lastly, in a large survey of incarcerated persons in the United Kingdom, Singleton et al13 determined that 56% of 2371 men and 31% of 771 women were antisocial. Although not directly comparable to our study, these studies point to the frequency with which ASPD is seen in prison set- tings in both the United States and the United Kingdom, particularly among violent offenders. These figures are substantially higher than what has been reported in the general popula- tion, as mentioned earlier.
Offenders with ASPD are much more likely to have other types of mental illness. Like their antisocial counterparts in the community, offenders had high rates of mood, anxiety, sub- stance use, and somatoform disorders, and BPD.1-5 The pattern mirrors what is seen in clinical samples, except per- haps for even higher rates of substance use disorders.29-32 This latter finding could reflect the influence of having a predominantly male sample, or the fact that the most common criminal offenses in this sample were substance related. With few exceptions, the rates of psychiatric comorbidity were mark- edly higher for the offenders with ASPD. This finding is similar to what our group reported in formerly hospi- talized antisocial men.30
Fifty-six percent of the offenders with ASPD and 24% of the remain- der screened positive for a lifetime psychotic disorder, albeit most were substance-related. These figures may seem excessive, yet should be placed into perspective. First, prevalence for schizophrenia/psychotic disorder not otherwise specified (NOS) cases is not out of line with what has been previously reported in correctional samples.33,34 In fact, nearly all offenders met criteria for a lifetime substance use disorder (and for many, the sub- stance misuse/manufacture contributed to their incar- ceration). Psychotic features are commonly observed in substance abusers, particularly when stimulants (eg, methamphetamine) are involved.34,35 Further, it may be that the MINI-Plus overdiagnoses psychotic disorders. The studies of both Sheehan et al22 and Otsubo et al37 report a relatively high rate of false-positive diagnoses of psychotic disorders with the MINI. Lastly, the MINI- Plus has not been standardized in the setting of criminal prosecution and incarceration—unusual experiences that may contribute to elevations in instruments designed to measure strange experiences.
The overlap with BPD merits comment. In this study, 44% of antisocial offenders also met criteria for BPD, not unlike what Zlotnick14 and others15 have reported. We have already written about offenders with BPD, who were more likely to be female, have high suicide risk scores, have substantial psychiatric comorbidity, and have impaired quality of life.38
Not surprising was the fact that antisocial offend- ers were more likely to report a history of prior mental health treatment and impaired quality of life than were nonantisocial subjects, as indicated by scores on the SF-36 subscales. These findings have been reported in clinical samples,29 and were confirmed in our follow-up of antisocial men.29,39 Thus, these findings are compatible with clinical studies that indicate that ASPD subjects experience substantial psychological distress, which impairs their ability to function in important life domains.
Our subanalysis on antisocial offenders with and without ADHD was also informative. As expected, those with ADHD were more severe. They had higher suicide risk scores and a higher frequency of mood dis- orders, panic disorder, and somatoform disorders (especially body dys- morphic disorder). The association of ADHD with body dysmorphic dis- order is intriguing, and although not previously reported, may possibly relate to negative self-image common to many persons with ADHD.40,41 The prevalence of ADHD in antisocial offenders (33%) is lower than that reported in a study of 105 antisocial inmates (65%) in Turkey.42 In that study, although psy- chiatric comorbidity was not assessed, those with ASPD and comorbid ADHD had higher rates of childhood neglect, self-injurious behavior, and suicide attempts. The latter finding is particular intriguing, and partially replicates our finding that antisocial offenders with ADHD are at special risk for suicidal behavior. Although the association of ADHD in adults with ASPD has rarely been examined, follow-up studies of ADHD show that the co-occurrence of ADHD and ASPD predicts earlier onset of addictive behaviors and criminality.43,44
There are several limitations to acknowledge in this study. First, because this sample consisted of offenders newly committed to the general population of a recep- tion unit at a state prison, the results may not generalize to incarcerated offenders as a whole, or to probationers or parolees. Because there were relatively few women in the study, caution should be used in attempting to gen- eralize the findings to this population. Second, while recall bias could have altered reports of symptoms, the potential for bias is likely reduced by the use of multiple validated self-report measures. Although the MINI-Plus itself is widely used and has acceptable reliability and validity with most diagnostic categories, there is some evidence that the instrument may overdiagnose some disorders, including psychoses. Third, the ASPD diag- nosis was based on a single instrument, and there was no effort to interview family members or other infor- mants, who could have provided additional informa- tion. Lastly, although it appeared that subjects were forthright in their reporting symptoms of mental illness, substance misuse, and ASPD, some degree of under- reporting of antisocial behaviors and overreporting of symptoms of mental illness is possible.
The current study was not developed as an epidemio- logic study and involved only newly committed offend- ers without special security or medical designation. Nonetheless, the findings suggest that ASPD occurs fre- quently in prison and is nearly as common in women as in men. A critical implication is that correctional systems should not overlook the diagnosis of ASPD in women. Offenders with ASPD are more likely to report poorer mental health and social functioning, to have substantial psychiatric comorbidity, and to report higher suicide risk, and for these reasons are likely to require more intensive mental health services than oth- ers. These findings should contribute to discussions regarding the appropriate management of persons with ASPD in correctional settings.
ACKNOWLEDGEMENT: We wish to acknowledge the contri- butions of Maggie Graeber, Brett McCormick, and Court- ney Hale for their help in data collection. Leonard Welch, PhD, Bob Schultz, and the staff at IMCC helped to facili- tate interviewing, for which we are grateful.
DISCLOSURES: Dr. Black receives research/grant support from AstraZeneca and Forest Laboratories and is a con- sultant to Jazz Pharmaceuticals. Drs. Gunter, Loveless, Allen, and Sieleni report no financial relationship with any company whose products are mentioned in this arti- cle or with manufacturers of competing products.
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