Offenders and non-offenders with schizophrenia spectrum disorders: the crime-preventive potential of sufficient embedment in the mental healthcare and support system

Background Suffering from schizophrenia spectrum disorder (SSD) has been well-established as a risk factor for offending. However, the majority of patients with an SSD do not show aggressive or criminal behavior. Yet, there is little research on clinical key features distinguishing offender from non-offender patients. Previous results point to poorer impulse control, higher levels of excitement, tension, and hostility, and worse overall cognitive functioning in offender populations. This study aimed to detect the most indicative distinguishing clinical features between forensic and general psychiatric patients with SSD based on the course of illness and the referenced hospitalization in order to facilitate a better understanding of the relationship between violent and non-violent offenses and SSD. Methods Our study population consisted of forensic psychiatric patients (FPPs) with a diagnosis of F2x (ICD-10) or 295.x (ICD-9) and a control group of general psychiatric patients (GPPs) with the same diagnosis, totaling 740 patients. Patients were evaluated regarding their medical (and, if applicable, criminal) history and the referenced psychiatric hospitalization. Supervised machine learning (ML) was used to exploratively evaluate predictor variables and their interplay and rank them in accordance with their discriminative power. Results Out of 194 possible predictor variables, the following 6 turned out to have the highest influence on the model: olanzapine equivalent at discharge from the referenced hospitalization, a history of antipsychotic prescription, a history of antidepressant, benzodiazepine or mood stabilizer prescription, medication compliance, outpatient treatment(s) in the past, and the necessity of compulsory measures. Out of the seven algorithms applied, gradient boosting emerged as the most suitable, with an AUC of 0.86 and a balanced accuracy of 77.5%. Discussion Our study aimed to identify the most influential illness-related predictors, distinguishing between FPP and GPP with SSD, thus shedding light on key differences between the two groups. To our knowledge, this is the first study to compare a homogenous sample of FPP and GPP with SSD regarding their symptom severity and course of illness using highly sophisticated statistical approaches with the possibility of evaluating the interplay of all factors at play.


PH6
History of disorders of affect or drive Yes, if he/she (had) experienced any mania-and/or depression-like symptoms with the consequence of any type of functional impairment (distress and/or disability)

PH7
History of negative symptoms Yes, if he/she (had) experienced any types of negative symptoms which are listed in the positive and negative syndrome scale (PANSS), which cannot be better explained by other causes (such as, for example, another mental illness)

PH10a
History of suicide attempts Yes, if he/she had harmed himself/herself intentionally with suicidal intent at any one time before the investigated offence respectively the time of the referenced hospitalization

PH11a
History of endangerment of others Yes, if, at any one time before the investigated offence respectively the referenced hospitalization, he/she had deliberately or negligently put one or more other person(s) at any type of risk (e.g., by the exertion of violence), which entailed the potential or actual consequence of a substantial mental and/or physical impairment of the corresponding person(s)

PH12a
Was there ever any compulsory measure during a hospitalization used?
Yes, if one or more of the following measures had been forced upon the patient in a psychiatric hospital at any one time before the investigated offence respectively the referenced hospitalization: involuntary isolation mechanical fixation (any type) -compulsory medication (oral AND/OR parenteral) -involuntary retention in the clinic (after voluntary admission)

PH13
Alcohol abuse Yes, if he/she (had) had an alcohol consumption pattern corresponding to the ICD-10 diagnosis ''Harmful use (F10.1)'' or ''Dependence syndrome (F10.2x)'' at the time of or at any one time before the investigated offence respectively the referenced hospitalization

PH14a
No drug abuse Yes, if he/she did not have and had not had a substance consumption pattern corresponding to the ICD-10 diagnosis ''Harmful use (F1x.1)'' or ''Dependence syndrome (F1x.2x)'' at the time of and at any one time before the investigated offence respectively the referenced hospitalization.In this item, the term 'substance' refers to illicit drugs and prescription medications but not to alcohol.

PH15a
Presence of a personality disorder (PD)?
Yes, if he/she had ever been diagnosed with any personality disorder listed in the ICD-10 (F60.x,F61) and/or the DSM-V

PH16a
Personality disorder: paranoid Yes, if he/she was diagnosed with paranoid personality disorder and/or exhibited a stable pattern of symptoms that can be considered compatible with a paranoid personality disorder (ICD-10: F60.0) or a paranoid accentuation of personality traits (ICD-10: Z73.1) at the time of or at any time before the investigated offence respectively the referenced hospitalization

PH16b
Personality disorder: schizoid Yes, if he/she was diagnosed with schizoid personality disorder and/or exhibited a stable pattern of symptoms that can be considered compatible with a schizoid personality disorder (ICD-10: F60.1) or a schizoid accentuation of personality traits (ICD-10: Z73.1) at the time of or at any time before the investigated offence respectively the referenced hospitalization

PH16c
Personality disorder: dissocial Yes, if he/she was diagnosed with dissocial or antisocial personality disorder and/or exhibited a stable pattern of symptoms that can be considered compatible with a dissocial personality disorder (ICD-10: F60.2) or a dissocial accentuation of personality traits (ICD-10: Z73.1) at the time of or at any time before the investigated offence respectively the referenced hospitalization

PH16d
Personality disorder: emotionally unstable Yes, if he/she was diagnosed with emotionally unstable or borderline personality disorder and/or exhibited a stable pattern of symptoms that can be considered compatible with an emotionally unstable personality disorder (ICD-10: F60.3x) or an emotionally unstable accentuation of personality traits (ICD-10: Z73.1) at the time of or at any time before the investigated offence respectively the referenced hospitalization

PH16e
Personality disorder: anancastic Yes, if he/she was diagnosed with anancastic or obsessive-compulsive personality disorder and/or exhibited a stable pattern of symptoms that can be considered compatible with an anancastic personality disorder (ICD-10: F60.5) or an anancastic accentuation of personality traits (ICD-10: Z73.1) at the time of or at any time before the investigated offence respectively the referenced hospitalization

PH16f
Personality disorder: dependent Yes, if he/she was diagnosed with dependent personality disorder and/or exhibited a stable pattern of symptoms that can be considered compatible with a dependent personality disorder (ICD-10: F60.7) or a dependent accentuation of personality traits (ICD-10: Z73.1) at the time of or at any time before the investigated offence respectively the referenced hospitalization

PH16g
Personality disorder: histrionic Yes, if he/she was diagnosed with histrionic personality disorder and/or exhibited a stable pattern of symptoms that can be considered compatible with a histrionic personality disorder (ICD-10: F60.4) or a histrionic accentuation of personality traits (ICD-10: Z73.1) at the time of or at any time before the investigated offence respectively the referenced hospitalization

PH16h
Personality disorder: narcissistic Yes, if he/she was diagnosed with narcissistic personality disorder and/or exhibited a stable pattern of symptoms that can be considered compatible with a narcissistic personality disorder (ICD-10: F60.8) or a narcissistic accentuation of personality traits (ICD-10: Z73.1) at the time of or at any time before the investigated offence respectively the referenced hospitalization

PH17a
Any other psychiatric comorbidity Yes, if he/she was diagnosed with any mental illness listed in the ICD-10 or DSM-5 at the time of the investigated offence except for the ones covered in the aforementioned items
Yes, if he/she had visited a mental health care provider (psychologist and/or psychiatrist) as an outpatient at any time before the investigated offence respectively the referenced hospitalization, regardless of the duration of said treatment
Yes, if he/she had been an inpatient and/or a semi-inpatient in a mental health care institution at any time before the investigated offence respectively the referenced hospitalization, regardless of the duration of said treatment

PH22a
Was the patient ever compulsorily admitted?
Yes, if he/she had been involuntarily admitted to any mental health care institution by order of an authorised person (such as a physician) at any one time before the investigated offence respectively the referenced hospitalization.Compulsory admission is defined as application of the Swiss "Fürsorgerische Unterbringung (FU)" OR "Fürsorgerischer Freiheitsentzug (FFE)" according to the Swiss child and adult protection law (KESR).

PH23a
Antipsychotic medication Yes, if he/she had been prescribed any antipsychotic medication at any time before the investigated offence respectively the referenced hospitalization Yes, if he/she, mental health professionals and trusted private persons (e.g., close family members) had not reported/documented a lack of compliance/adherence to any antipsychotic medications at any time before the investigated offence AND if mental health professionals and trusted private persons (e.g., close family members) had not had reasonable grounds for suspecting that the patient lacked medication compliance/adherence to any antipsychotic medications at any time before the investigated offence respectively the referenced hospitalization.legal guardian repeatedly had advised and/or urged him/her to seek psychiatric treatment at any time before the investigated offence AND/OR if he/she had been involuntarily admitted to a mental health care institution on request of any relative(s) and/or legal guardian at any time before the investigated offence resp.the ref.hospitalization Score in the PANSS item 'mannerisms and posturing' at the time of discharge from the referenced hospital PA51 PANSS at discharge: Scale Depression Score in the PANSS item 'depression' at the time of discharge from the Score in the PANSS item 'unusual thought content' at the time of discharge from the referenced hospital PA55 PANSS at discharge: Scale Disorientation Score in the PANSS item 'disorientation' at the time of discharge from the Score in the PANSS item 'active social avoidance' at the time of discharge from the referenced hospital PAS_D PANNS Score at discharge PANSS total score at the time of discharge from the referenced hospital Yes, if measures to counteract the problems in treatment were taken (e.g.establishment of some form of assisted living, compulsory admissions, establishment of legal supervision)PH26aAlerts by third parties about danger originating from the patient Yes, if any report from a private person, an official, a public authority and/or a person involved in the individual's care had indicated a substantially increased risk for any type of delinquency originating from the individual at any time before the investigated offence resp.thereferencedhospitalization(PH26b: was there any reaction)PH27aLegal complaints by third parties Yes, if any private person, official, public authority and/or person involved in the individual's care had filed a police/legal complaint at any time before the investigated offence resp.thereferencedhospitalizationPH27bEfforts by third parties to seek psychiatric helpYes, if he/she, mental health professionals or trusted private persons (e.g., close family members) had reported/documented that any relative(s) and/or Yes, if his/her diagnosis of schizophrenia spectrum disorder (ICD-10: F2x.x) at the time of discharge from the referenced forensic hospital had been given within the first month after admission to the referenced forensic hospital Yes, if he/she showed any physical or verbal aggressions towards one or more staff member(s) or one or more other patient(s) at any one time during the referenced hospitalization.hospitalization Yes, if, at any one time during the referenced hospitalization, mental health professional confirmed that he/she had engaged in the prohibited consumption and/or trade of substances (including alcohol and prescription medications) OR if, at any one time during the referenced hospitalization, there were reasonable grounds for suspecting that he/she had engaged in the prohibited consumption and/or trade of substances (