Neural dysfunction and violence in schizophrenia: an fMRI investigation

Task-related brain activation associated with violence in patients with schizophrenia: A meta-analysis

This study investigates specific changes in brain function during cognitive and emotional tasks in patients with schizophrenia and a history of violence (VSCZ) compared with non-violent patients with schizophrenia and healthy controls. A comprehensive literature search was conducted at the Web of Science, Medline, and PubMed. Ten studies met the inclusion criteria. In which, eight studies compared brain activation between patients with VSCZ and non-violent patients with schizophrenia, and the former exhibited increased activation at the middle occipital gyrus and rectus compared with the latter. Seven studies compared brain activation between patients with VSCZ and controls, and the former exhibited increased activation at the anterior cingulate cortex, cerebellum VI region, lingual gyrus and fusiform. Subgroup analysis in five studies performing emotional tasks revealed that patients with VSCZ showed increased activation at the middle occipital gyrus compared with non-violent patients with schizophrenia. Our findings suggest that abnormal emotion perception and regulation significantly contribute to the increased risk of violence in patients with schizophrenia. Notably, the middle occipital gyrus and rectus emerge as key neurophysiological correlates associated with this phenomenon.

Exploring Characteristics of Homicide Offenders With Schizophrenia Spectrum Disorders Via Machine Learning

The link between schizophrenia and homicide has long been the subject of research with significant impact on mental health policy, clinical practice, and public perception of people with psychiatric disorders. The present study investigates factors contributing to completed homicides committed by offenders diagnosed with schizophrenia referred to a Swiss forensic institution, using machine learning algorithms. Data were collected from 370 inpatients at the Centre for Inpatient Forensic Therapy at the Zurich University Hospital of Psychiatry. A total of 519 variables were explored to differentiate homicidal and other (violent and non-violent) offenders. The dataset was split employing variable filtering, model building, and selection embedded in a nested resampling approach. Ten factors regarding criminal and psychiatric history and clinical factors were identified to be influential in differentiating between homicidal and other offenders. Findings expand the research on influential factors for completed homicide in patients with schizophrenia. Limitations, clinical relevance, and future directions are discussed.

Comparison of local activation, functional connectivity, and structural connectivity in the N-back task

The N-back task is widely used to investigate working memory. Previous functional magnetic resonance imaging (fMRI) studies have shown that local brain activation depends on the difficulty of the N-back task. Recently, changes in functional connectivity and local activation during a task, such as a single-hand movement task, have been reported to give the distinct information. However, previous studies have not investigated functional connectivity changes in the entire brain during N-back tasks. In this study, we compared alterations in functional connectivity and local activation related to the difficulty of the N-back task. Because structural connectivity has been reported to be associated with local activation, we also investigated the relationship between structural connectivity and accuracy in a N-back task using diffusion tensor imaging (DTI). Changes in functional connectivity depend on the difficulty of the N-back task in a manner different from local activation, and the 2-back task is the best method for investigating working memory. This indicates that local activation and functional connectivity reflect different neuronal events during the N-back task. The top 10 structural connectivities associated with accuracy in the 2-back task were locally activated during the 2-back task. Therefore, structural connectivity as well as fMRI will be useful for predicting the accuracy of the 2-back task.

The Static and dynamic functional connectivity characteristics of the left temporoparietal junction region in schizophrenia patients with auditory verbal hallucinations during low-frequency rTMS treatment

BACKGROUND

Auditory verbal hallucinations (AVH) are a core symptom of schizophrenia. Low-frequency (e.g., 1 Hz) repetitive transcranial magnetic stimulation (rTMS) targeting language processing regions (e.g., left TPJ) has been evident as a potential treatment for AVH. However, the underlying neural mechanisms of the rTMS treatment effect remain unclear. The present study aimed to investigate the effects of 1 Hz rTMS on functional connectivity (FC) of the temporoparietal junction area (TPJ) seed with the whole brain in schizophrenia patients with AVH.

METHODS

Using a single-blind placebo-controlled randomized clinical trial, 55 patients with AVH were randomly divided into active treatment group (n = 30) or placebo group (n = 25). The active treatment group receive 15-day 1 Hz rTMS stimulation to the left TPJ, whereas the placebo group received sham rTMS stimulation to the same site. Resting-state fMRI scans and clinical measures were acquired for all patients before and after treatment. The seed-based (left TPJ) static and DFC was used to assess the connectivity characteristics during rTMS treatment in patients with AVH.

RESULTS

Overall, symptom improvement following 1 Hz rTMS treatment was found in the active treatment group, whereas no change occurred in the placebo group. Moreover, decreased static FC (SFC) of the left TPJ with the right temporal lobes, as well as increased SFC with the prefrontal cortex and subcortical structure were observed in active rTMS group. Increased dynamic FC (DFC) of the left TPJ with frontoparietal areas was also found in the active rTMS group. However, seed-based SFC and DFC were reduced to a great extent in the placebo group. In addition, these changed FC (SFC) strengths in the active rTMS group were associated with reduced severity of clinical outcomes (e.g., positive symptoms).

CONCLUSION

The application of 1 Hz rTMS over the left TPJ may affect connectivity characteristics of the targeted region and contribute to clinical improvement, which shed light on the therapeutic effect of rTMS on schizophrenia with AVH.

Spatial and chronic differences in neural activity in medicated and unmedicated schizophrenia patients

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The medicated schizophrenia group yielded concordant activity among three right lateralized frontal clusters and a left lateralized parietal cluster.

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The unmedicated schizophrenia group yielded concordant activity among right lateralized frontal-parietal regions.

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A neural compensatory mechanism in schizophrenia.

A major caveat with investigations on schizophrenic patients is the difficulty to control for medication usage across samples as disease-related neural differences may be confounded by medication usage. Following a thorough literature search (632 records identified), we included 37 studies with a total of 740 medicated schizophrenia patients and 367 unmedicated schizophrenia patients. Here, we perform several meta-analyses to assess the neurofunctional differences between medicated and unmedicated schizophrenic patients across fMRI studies to determine systematic regions associated with medication usage. Several clusters identified by the meta-analysis on the medicated group include three right lateralized frontal clusters and a left lateralized parietal cluster, whereas the unmedicated group yielded concordant activity among right lateralized frontal-parietal regions. We further explored the prevalence of activity within these regions across illness duration and task type. These findings suggest a neural compensatory mechanism across these regions both spatially and chronically, offering new insight into the spatial and temporal dynamic neural differences among medicated and unmedicated schizophrenia patients.

Increased cingulo-orbital connectivity is associated with violent behaviours in schizophrenia

OBJECTIVE

Although schizophrenia patients are at a heightened risk of exhibiting violent behaviours compared to the general population, few functional neuroimaging studies have explored the aberrant neurocircuitry underpinning such behaviours. This study aimed to identify disrupted resting-state activity and functional connectivity in schizophrenia patients with a history of violence.

METHODS

Resting state functional magnetic resonance imaging data was collected from 62 schizophrenia patients and 25 healthy controls. Voxel-wise analyses of fractional amplitude of low frequency fluctuations (fALFF) were implemented to investigate disrupted regional patterns of spontaneous brain activity. Brain regions which yielded significant differences between groups were subsequently used as data-driven seeds for functional connectivity analyses. Finally, significant alterations (activity and connectivity) were correlated with lifetime violent behaviours.

RESULTS

When compared to healthy controls, schizophrenia patients exhibited reduced fALFF in multiple brain regions including the (subgenual) anterior cingulate cortex (ACC), posterior cingulate cortex, precuneus cortex and left lateral orbitofrontal cortex (OFC). Seed-to-voxel analyses yielded significantly enhanced connectivity between the ACC and left OFC. The heightened functional connectivity between the latter two regions predicted the number of violent behaviours reported by schizophrenia patients.

CONCLUSION

The current study demonstrated that the functional connectivity of brain regions associated with emotion regulation is impaired in schizophrenia and associated with violent antecedents among patients. This result is consistent with predominant theoretical models proposing that the OFC plays a critical role in the neurobiology of violence.

Aberrant Functional Connectivity of the Orbitofrontal Cortex Is Associated With Excited Symptoms in First-Episode Drug-Naïve Patients With Schizophrenia

BACKGROUND

Schizophrenia (SZ) is associated with the highest disability rate among serious mental disorders. Excited symptoms are the core symptoms of SZ, which appear in the early stage, followed by other stages of the disease subsequently. These symptoms are destructive and more prone to violent attacks, posing a serious economic burden to the society. Abnormal spontaneous activity in the orbitofrontal cortex had been reported to be associated with excited symptoms in patients with SZ. However, whether the abnormality appears in first-episode drug-naïve patients with SZ has still remained elusive.

METHODS

A total of 56 first-episode drug-naïve patients with SZ and 27 healthy controls underwent resting-state functional magnetic resonance imaging (rs-fMRI) and positive and negative syndrome scale (PANSS). First, differences in fractional amplitude of low-frequency fluctuations (fALFF) between first-episode drug-naïve patients with SZ and healthy controls were examined to identify cerebral regions exhibiting abnormal local spontaneous activity. Based on the fALFF results, the resting-state functional connectivity analysis was performed to determine changes in cerebral regions exhibiting abnormal local spontaneous activity. Finally, the correlation between abnormal functional connectivity and exciting symptoms was analyzed.

RESULTS

Compared with the healthy controls, first-episode drug-naïve patients with SZ showed a significant decrease in intrinsic activity in the bilateral precentral gyrus, bilateral postcentral gyrus, and the left orbitofrontal cortex. In addition, first-episode drug-naïve patients with SZ had significantly reduced functional connectivity values between the left orbitofrontal cortex and several cerebral regions, which were mainly distributed in the bilateral postcentral gyrus, the right middle frontal gyrus, bilateral paracentral lobules, the left precentral gyrus, and the right median cingulate. Further analyses showed that the functional connectivity between the left orbitofrontal cortex and the left postcentral gyrus, as well as bilateral paracentral lobules, was negatively correlated with excited symptoms in first-episode drug-naïve patients with SZ.

CONCLUSION

Our results indicated the important role of the left orbitofrontal cortex in first-episode drug-naïve patients with SZ and suggested that the abnormal spontaneous activity of the orbitofrontal cortex may be valuable to predict the occurrence of excited symptoms. These results may provide a new direction to explore the excited symptoms of SZ.

Pituitary volume in people with chronic schizophrenia: Clarifying the roles of serious violence and childhood maltreatment

Aberrations in stress-linked hypothalamic-pituitary-adrenal axis function have been independently associated with schizophrenia, antisocial behaviour and childhood maltreatment. In this study, we examined pituitary volume (PV) in relation to childhood maltreatment (physical abuse, sexual abuse, neglect) in men (i) with schizophrenia and a history of serious violence (n = 13), (ii) with schizophrenia but without a history of serious violence (n = 15), (iii) with antisocial personality disorder (ASPD) and a history of serious violence (n = 13), and (iv) healthy participants without a history of violence (n = 15). All participants underwent whole-brain magnetic resonance imaging. Experiences of childhood maltreatment were rated based on interviews (for all), and case history and clinical/forensic records (for patients only). There was a trend for smaller PV, on average, in schizophrenia patients (regardless of a history of violence), compared to the healthy group and the ASPD group; other group differences in PV were non-significant. Sexual abuse ratings correlated negatively with PVs in ASPD participants, but no significant association between childhood maltreatment and PV was found in schizophrenia participants. Our findings are consistent with previous evidence of smaller-than-normal PV in chronic schizophrenia patients, and suggest that illness-related influences may mask the possible sexual abuse-smaller PV association, seen here in ASPD, in this population.

Forensic psychiatric evaluation of 187 homicidal assailants with and without a schizophrenia spectrum disorder: Clinical, criminological and behavioral characteristics

Intentional homicide, a declining phenomenon in Italy, represents one of the most extreme forms of violence. A specific subgroup of homicidal assailants is represented by those affected by mental disorders, where the relationship between psychopathology and characteristics of the homicidal attack is not yet fully understood. We analyzed the case files of 187 homicides or attempted homicides, in which the defendant had undergone a forensic psychiatric evaluation within the previous 10 years from a single forensic psychiatric center. We described and analyzed the perpetrator, victim and criminological characteristics of the study cases. A diagnosis of a schizophrenia spectrum disorder, a victim who was the perpetrator's biological child and absence of a personality disorder diagnosis were associated with an increased probability of having been adjudicated as lacking or having substantially diminished criminal responsibility due to a mental disorder. Homicidal assailants with a schizophrenia spectrum disorder showed some differences in criminological characteristics compared with murderers without a schizophrenic spectrum disorder, including a higher incidence of parricide, interruption of pharmacotherapy before the crime and disorganized post-crime behavior.

Differences in the amplitude of low-frequency fluctuation between methamphetamine and heroin use disorder individuals: A resting-state fMRI study

INTRODUCTION

Methamphetamine has surpassed heroin as the most popular abused drug in China. Although the use of both heroin and methamphetamine leads to use disorders through dysfunction of the dopamine pathway, the incidence of psychiatric disorder caused by methamphetamine abuse is higher than the incidence of psychiatric disorder caused by heroin abuse. The difference in resting-state function between heroin use disorder (HUD) and methamphetamine use disorder (MAUD) and the relationship between resting-state function and psychiatric disorder related to MAUD are unknown.

METHODS

In the present study, 21 male individuals with MAUD, 21 demographically matched individuals with HUD, and 21 normal controls (NC) were recruited. The amplitude of low-frequency fluctuation (ALFF) during resting-state brain function was measured by magnetic resonance imaging. Psychiatric status was evaluated by the Symptom Checklist-90 (SCL90).

RESULTS

Individuals with MAUD had increased SCL90 scores compared to those of the NC for anxiety, paranoia, and additional items, and the hostility score was significantly increased compared to that of individuals with HUD. There is no significant difference between HUD and NC individuals. Individuals with MAUD had increased ALFF compared to those of the NC for thalamus, right postcentral, and right inferior temporal gyri, but a decreased ALFF in the cerebellum. Individuals with HUD had significantly increased ALFF compared to those of the NC for left middle frontal gyrus but a decreased ALFF in the left postcentral gyrus. Individuals with MAUD had significantly increased ALFF compared to those of the HUD for thalamus, the right inferior temporal, and bilateral postcentral gyri, and the ALFF of cerebellum and left middle frontal was significantly increased.

CONCLUSIONS

Methamphetamine can induce more serious psychiatric disorders than heroin. The resting-state function involved in mood adjustment, the auditory, and memory-related brain regions may affect psychotic symptoms related to MAUD.

Biological Aspects of Aggression and Violence in Schizophrenia

Although the majority of patients with schizophrenia are not actually violent, an increased tendency toward violent behaviors is known to be associated with schizophrenia. There are several factors to consider when identifying the subgroup of patients with schizophrenia who may commit violent or aggressive acts. Comorbidity with substance abuse is the most important clinical indicator of increased aggressive behaviors and crime rates in patients with schizophrenia. Genetic studies have proposed that polymorphisms in the promoter region of the serotonin transporter gene and in the catechol-O-methyltransferase gene are related to aggression. Neuroimaging studies have suggested that fronto-limbic dysfunction may be related to aggression or violence. By identifying specific risk factors, a more efficient treatment plan to prevent violent behavior in schizophrenia will be possible. Management of comorbid substance use disorder may help prevent violent events and overall aggression. Currently, clozapine may be the only effective antipsychotic medication to repress aggressive behavior. With the current medical field moving toward tailored medicine, it is important to identify vulnerable schizophrenia populations and provide efficient treatment.

Stimuli, presentation modality, and load-specific brain activity patterns during n-back task

Working memory (WM) refers to a set of cognitive processes that allows for the temporary storage and manipulation of information, crucial for everyday life skills. WM deficits are present in several neurological, psychiatric, and neurodevelopmental disorders, thus making the full understanding of its neural correlates a key aspect for the implementation of cognitive training interventions. Here, we present a quantitative meta-analysis focusing on the underlying neural substrates upon which the n-back, one of the most commonly used tasks for WM assessment, is believed to rely on, as highlighted by functional magnetic resonance imaging and positron emission tomography findings. Relevant published work was scrutinized through the activation likelihood estimate (ALE) statistical framework in order to generate a set of task-specific activation maps, according to n-back difficulty. Our results confirm the known involvement of frontoparietal areas across different types of n-back tasks, as well as the recruitment of subcortical structures, cerebellum and precuneus. Specific activations maps for four stimuli types, six presentation modalities, three WM loads and their combination are provided and discussed. Moreover, functional overlap with resting-state networks highlighted a strong similarity between n-back nodes and the Dorsal Attention Network, with less overlap with other networks like Salience, Language, and Sensorimotor ones. Additionally, neural deactivations during n-back tasks and their functional connectivity profile were examined. Clinical and functional implications are discussed in the context of potential noninvasive brain stimulation and cognitive enhancement/rehabilitation programs.

A Systematic Literature Review of Neuroimaging of Psychopathic Traits

INTRODUCTION

Core psychopathy is characterized by grandiosity, callousness, manipulativeness, and lack of remorse, empathy, and guilt. It is often comorbid with conduct disorder and antisocial personality disorder (ASPD). Psychopathy is present in forensic as well as prison and general populations. In recent years, an increasing amount of neuroimaging studies has been conducted in order to elucidate the obscure neurobiological etiology of psychopathy. The studies have yielded heterogenous results, and no consensus has been reached.

AIMS

This study systematically reviewed and qualitatively summarized functional and structural neuroimaging studies conducted on individuals with psychopathic traits. Furthermore, this study aimed to evaluate whether the findings from different MRI modalities could be reconciled from a neuroanatomical perspective.

MATERIALS AND METHODS

After the search and auditing processes, 118 neuroimaging studies were included in this systematic literature review. The studies consisted of structural, functional, and diffusion tensor MRI studies.

RESULTS

Psychopathy was associated with numerous neuroanatomical abnormalities. Structurally, gray matter anomalies were seen in frontotemporal, cerebellar, limbic, and paralimbic regions. Associated gray matter volume (GMV) reductions were most pronounced particularly in most of the prefrontal cortex, and temporal gyri including the fusiform gyrus. Also decreased GMV of the amygdalae and hippocampi as well the cingulate and insular cortices were associated with psychopathy, as well as abnormal morphology of the hippocampi, amygdala, and nucleus accumbens. Functionally, psychopathy was associated with dysfunction of the default mode network, which was also linked to poor moral judgment as well as deficient metacognitive and introspective abilities. Second, reduced white matter integrity in the uncinate fasciculus and dorsal cingulum were associated with core psychopathy. Third, emotional detachment was associated with dysfunction of the posterior cerebellum, the human mirror neuron system and the Theory of Mind denoting lack of empathy and persistent failure in integrating affective information into cognition.

CONCLUSIONS

Structural and functional aberrancies involving the limbic and paralimbic systems including reduced integrity of the uncinate fasciculus appear to be associated with core psychopathic features. Furthermore, this review points towards the idea that ASPD and psychopathy might stem from divergent biological processes.

Neural networks of aggression: ALE meta-analyses on trait and elicited aggression

There is considerable evidence that emotion dysregulation and self-control impairments lead to escalated aggression in populations with psychiatric disorders. However, convergent quantitative evidence on the neural network explaining how aggression arises is still lacking. To address this gap, peak activations extracted from extant functional magnetic resonance imaging (fMRI) studies were synthesized through coordinate-based meta-analyses. A systematic search in the PubMed database was conducted and 26 fMRI studies met the inclusion criteria. Three separate activation likelihood estimation (ALE) meta-analyses were performed on (1) individual differences in trait aggression (TA) studies, (2) individual differences in TA studies examining executive functioning, and (3) elicited aggression (EA) studies across fMRI behavioral paradigms. Ensuing clusters from ALE meta-analyses were further treated as seeds for follow-up investigations on consensus connectivity networks (CCN) delineated from meta-analytic connectivity modeling (MACM) and resting-state functional connectivity (RSFC) to further characterize their physiological functions. Finally, we obtained a data-driven functional characterization of the ensuing clusters and their networks. This approach offers a boarder view of the ensuing clusters using a boarder network perspective. In TA, aberrant brain activations were found only in the right precuneus. Follow-up analyses revealed that the precuneus seed was within the frontal-parietal network (FPN) associated with action inhibition, visuospatial processing and higher-level cognition. With further restricting to only experiments examining executive functioning, convergent evidence was found in the right rolandic operculum (RO), midcingulate cortex (MCC), precentral gyrus (PrG) and precuneus. Follow-up analyses suggested that RO, MCC and PrG may belong to a common cognitive control network, while the MCC seems to be the hub of this network. In EA, we only revealed a convergent region in the left postcentral gyrus. Follow-up CCN analyses and functional characterizations suggested that this region may also belong to the same cognitive control network found in the TA sub-analysis. Our results suggested that escalated aggression arises from abnormal precuneus activities within the FPN, disrupting the recruitment of other large-scale networks such as adaptive cognitive control network. Consequently, failure to recruit such a network results in an inability to generate adaptive responses, increasing the likelihood of acting aggressively.

Comparative study of aggression - Dangerousness on patients with paranoid schizophrenia: Focus on demographic data, PANSS, drug use and aggressiveness

This cross sectional study aimed to compare the differences in psychopathology of Greek homicide and homicide attempters, patients with schizophrenia, with non violent individuals, suffering from schizophrenia. The study compared three Groups of 220 men, diagnosed with schizophrenia: (a) Group Α (Schizophrenia - No violence, (b) Group Β (Schizophrenia - with violence or violent crime), (c) Group C (Schizophrenia - not guilty by reason of insanity - violent crime). Several psychometric tools were used, such as M.I.N·I (Mini-International Neuropsychiatric Interview), PANSS scale (Positive and Negative Symptoms Scale). Most subjects suffered from paranoid schizophrenia. On factors such as demographic characteristics (i.e. current occupational status, living status), statistically significant findings were shown for Groups B and C vs Group A. Predisposing psychosocial factors, such as family conflicts and aggressiveness against family, were found to be statistically significant in differentiating violent versus nonviolent individuals with psychosis. They differed significantly in factors like history of juvenile delinquency, but also in the type of aggressiveness in general. These differences were confirmed on PANSS scale. In conclusion, the longer the history of aggressiveness is presented, the greater the chances are of individuals falling into Group C and it is possible to spend several years from the onset of the disease until the moment of crime.

Brain structure abnormalities in young women who presented conduct disorder in childhood/adolescence

The phenotype and genotype of antisocial behavior among females are different from those among males. Previous studies have documented structural brain alterations in males with antisocial behavior, yet little is known about the neural correlates of female antisocial behavior. The present study examined young women who had presented conduct disorder (CDW) prior to age 15 to determine whether brain abnormalities are present in adulthood and whether the observed abnormalities are associated with comorbid disorders or maltreatment that typically characterize this population. Using magnetic resonance imaging and voxel-based morphometry, we compared gray matter volumes (GMV) of 31 women who presented CD by midadolescence and 25 healthy women (HW), age, on average, 23 years. Participants completed structured, validated interviews to diagnose mental disorders, and validated questionnaires to document physical and sexual abuse. Relative to HW, CDW presented increased GMV in the left superior temporal gyrus that was associated with past alcohol and drug dependence, current use of alcohol and drugs, and current anxiety and depression symptoms and maltreatment. Additionally, CDW displayed reduced GMV in lingual gyrus, hippocampus, and anterior cingulate cortex that was associated with past comorbid disorders, current alcohol and drugs use, current anxiety and depression symptoms, and maltreatment. The CDW also presented reduced total GMV that was associated with past comorbid disorders and current anxiety/depression symptoms. Alterations of brain structure were observed among young adult females with prior CD, relative to HW, all of which were associated with internalizing and externalizing disorders and maltreatment that typically accompany CD.

Differences in Neuropsychological Functioning Between Homicidal and Nonviolent Schizophrenia Samples

Few studies have compared performance on neurocognitive measures between violent and nonviolent schizophrenia samples. A better understanding of neurocognitive dysfunction in violent individuals with schizophrenia could increase the efficacy of violence reduction strategies and aid in risk assessment and adjudication processes. This study aimed to compare neuropsychological performance between 25 homicide offenders with schizophrenia and 25 nonviolent schizophrenia controls. The groups were matched for age, race, sex, and handedness. Independent t-tests and Mann-Whitney U-tests were used to compare the schizophrenia groups' performance on measures of cognition, including composite scores assessing domain level functioning and individual neuropsychological tests. Results indicated the violent schizophrenia group performed worse on measures of memory and executive functioning, and the Intellectual Functioning composite score, when compared to the nonviolent schizophrenia sample. These findings replicate previous research documenting neuropsychological deficits specific to violent individuals with schizophrenia and support research implicating fronto-limbic dysfunction among violent offenders with schizophrenia.

Imaging Violence in Schizophrenia: A Systematic Review and Critical Discussion of the MRI Literature

Background: Persons with schizophrenia have a small but significant increase in risk of violence, which remains after controlling for known environmental risk factors. In vivo MRI-studies may point toward the biological underpinnings of psychotic violence, and neuroimaging has increasingly been used in forensic and legal settings despite unclear relevance. Objectives: (1) To present the first systematic review, following standardized guidelines, of MRI studies of violence with schizophrenia. (2) To critically discuss the promises and pitfalls of using this literature to understand violence in schizophrenia in clinical, forensic, and legal settings. Methods: Following the PRISMA guidelines and literature searches until January 2018, we found 21 original studies that fulfilled the inclusion criteria: (1) Studies of persons with schizophrenia, (2) a history of violence or aggressive behavior, (3) the use of one or more MRI-modalities (sMRI, DTI, fMRI). Results: The most consistent findings from the structural studies were reduced volumes of the hippocampus and the frontal lobe (in particular the orbitofrontal and anterior cingulate cortex) in schizophrenia patients with a history of violence or higher aggression scores. The functional studies mainly showed differences and aggression correlates in the frontal lobe and amygdala. However, the studies were methodologically heterogeneous, with four particular areas of concern: different definitions of violence, region of interest vs. whole-brain studies, small subject samples, and group comparisons in a heterogeneous diagnostic category (schizophrenia). Conclusion: The literature reports subtle, but inconsistent group level differences in brain structure and function associated with violence and aggression with schizophrenia, in particular in areas involved in the formation of psychosis symptoms and affective regulation. Due to methodological challenges the results should be interpreted with caution. In order to come closer to the neurobiological underpinnings of violence in schizophrenia future studies could: (1) address the neurobiological differences of premeditated and reactive violence, (2) use RDoC criteria, for example, or other symptom-based systems to categorize psychosis patients, (3) increase subject cohorts and apply new data driven methods. In this perspective, MRI-studies of violence in schizophrenia have the potential to inform clinical violence prediction and legal evaluations in the future.

Functional Neuroimaging Correlates of Aggression in Psychosis: A Systematic Review With Recommendations for Future Research

Background and methods: Aggression in psychosis is clinically important. We systematically compiled the evidence on functional correlates of aggression in psychosis searching PubMed, EMBASE, ScienceDirect, and PsycINFO until September 2017. We included studies reporting functional brain imaging correlates of aggression comparing: (1) affective or non-affective psychosis groups with a history of violence or with aggression operationalized using questionnaires, (2) affective or non-affective psychosis groups with a history of violence or with aggression operationalized using questionnaires to controls, (3) affective or non-affective psychosis groups with a history of violence or with aggression operationalized using questionnaires to controls with diagnoses other than affective or non-affective psychoses. We applied no language restriction and required patients to have a DSM or ICD diagnosis of affective or non-affective psychosis. Results: Our sample consisted of 12 studies with 334 patients and 113 controls. During n-back tasks, violent (VS) as opposed to non-violent persons with schizophrenia (NVS) hypoactivated their inferior parietal lobe. When anticipating shock, VS vs. NVS hyperactivated their medial prefrontal gyrus, cuneus, middle temporal gyrus, and middle occipital gyrus. When viewing negative emotional pictures, VS vs. NVS hyperactivated the middle frontal gyrus, inferior frontal gyrus, anterior cingulate, lingual gyrus, precentral gyrus, globus pallidus, mid-cingulate, and precuneus. Limitations: Due to the small number of available studies, sample overlap, and insufficient reporting of relevant moderators we could not conduct a meta-analysis. Conclusions: We found non-systematic functional correlates of aggression in schizophrenia. Only few studies using varied paradigms and often overlapping samples have been conducted. There have been no attempts to replicate any of the observed findings in the published literature. Focusing on future directions, we recommend that authors adhere to clear definitions of aggression, measurements of psychopathology, comorbidities, and medication. In particular, replication studies would allow for a better synthesis of the findings. PROSPERO Registration Number: CRD42016048579.

Neuropsychology and emotion processing in violent individuals with antisocial personality disorder or schizophrenia: The same or different? A systematic review and meta-analysis

OBJECTIVES

To assess whether there are shared or divergent (a) cognitive and (b) emotion processing characteristics among violent individuals with antisocial personality disorder and/or schizophrenia, diagnoses which are commonly encountered at the interface of mental disorder and violence. Cognition and emotion processing are incorporated into models of violence, and thus an understanding of these characteristics within and between disorder groups may help inform future models and therapeutic targets.

METHODS

Relevant databases (OVID, Embase, PsycINFO) were searched to identify suitable literature. Meta-analyses comparing cognitive function in violent schizophrenia and antisocial personality disorder to healthy controls were conducted. Neuropsychological studies not comparing these groups to healthy controls, and emotion processing studies, were evaluated qualitatively.

RESULTS

Meta-analyses indicated lower IQ, memory and executive function in both violent schizophrenia and antisocial personality disorder groups compared to healthy controls. The degree of deficit was consistently larger in violent schizophrenia. Both antisocial personality disorder and violent schizophrenia groups had difficulties in aspects of facial affect recognition, although theory of mind results were less conclusive. Psychopathic traits related positively to experiential emotion deficits across the two disorders. Very few studies explored comorbid violent schizophrenia and antisocial personality disorder despite this being common in clinical practice.

CONCLUSION

There are qualitatively similar, but quantitatively different, neuropsychological and emotion processing deficits in violent individuals with schizophrenia and antisocial personality disorder which could be developed into transdiagnostic treatment targets for violent behaviour. Future research should aim to characterise specific subgroups of violent offenders, including those with comorbid diagnoses.

Gender differences in neural correlates of stress-induced anxiety

Although gender differences have been identified as a crucial factor for understanding stress-related anxiety and associated clinical disorders, the neural mechanisms underlying these differences remain unclear. To explore gender differences in the neural correlates of stress-induced anxiety, the current study used functional magnetic resonance imaging to examine brain responses in 96 healthy men and women with commensurable levels of trait anxiety as they engaged in a personalized guided imagery paradigm to provoke stress and neutral-relaxing experiences. During the task, a significant gender main effect emerged, with men displaying greater responses in the caudate, cingulate gyrus, midbrain, thalamus, and cerebellum. In contrast, women showed greater responses in the posterior insula, temporal gyrus, and occipital lobe. Additionally, a significant anxiety ratings × gender interaction from whole-brain regression analyses was observed in the dorsomedial prefrontal cortex, left inferior parietal lobe, left temporal gyrus, occipital gyrus, and cerebellum (P < 0.05, whole-brain family-wise error corrected), with positive associations between activity in these regions and stress-induced anxiety in women, but negative associations in men, indicating that men and women differentially use neural resources when experiencing stress-induced anxiety. The findings suggest that in response to stress, there is a greater use of the medial prefrontal-parietal cortices in experiencing subjective anxiety in women, while decreased use of this circuit was associated with increased subjective anxiety states in men. The current study has implications for understanding gender-specific differences in stress-induced anxiety and vulnerability to stress-related clinical disorders, and for developing more effective treatment strategies tailored to each gender. © 2016 Wiley Periodicals, Inc.

18F-Fluorodeoxyglucose Positron Emission Tomography Cortical Metabolic Activity Associated with Distinct Agitation Behaviors in Alzheimer Disease

OBJECTIVE

This study aimed to investigate the neurobiologic correlates of two distinct clusters of agitation symptoms to identify the unique biologic substrates underlying agitated behaviors.

METHODS

Eighty-eight outpatients with mild to moderate Alzheimer disease (AD) were recruited from the VA Greater Los Angeles Healthcare System Geropsychiatry Outpatient Program. A cross-sectional investigation was conducted of the relationship between cerebral glucose metabolism measured via ¹⁸F-fluorodeoxyglucose positron emission tomography and agitated symptoms from the Neuropsychiatric Inventory (NPI) in patients with AD. Two empirically derived clusters of agitation symptoms were investigated: an Agitation factor comprising agitation/aggression and irritability/lability items of the NPI, and a Behavioral Dyscontrol factor comprising elation/euphoria, disinhibition, aberrant motor behavior, sleep, and appetite items of the NPI. Mean cerebral metabolism for patients who scored positively on each of the two factors was compared with mean cerebral metabolism for those who did not.

RESULTS

Patients with AD who scored positively on the Agitation factor showed reduced glucose metabolism of the right temporal, right frontal, and bilateral cingulate cortex. In contrast, the Behavioral Dyscontrol factor did not show specific neurobiologic correlates.

CONCLUSION

Symptoms encompassed within the Agitation factor have distinct neurobiologic underpinnings. The precipitants, course, and outcomes related to these symptoms may be unique from other neuropsychiatric symptoms characteristic of AD. Special attention to treatment of agitated behaviors involving anger, aggressiveness, hostility, and irritability/emotional lability is warranted, because they appear to reflect a clinically relevant symptom cluster with unique underlying neurobiologic correlates.

Murder and psychosis: Neuropsychological profiles of homicide offenders with schizophrenia

BACKGROUND

Neurocognitive dysfunction, a core feature of schizophrenia, is thought to contribute to the impulsive violent aggression manifested by some individuals with schizophrenia, but not enough is known about how homicidal individuals with schizophrenia perform on neuropsychological measures.

AIMS

The primary aim of our study was to describe the neuropsychological profiles of homicide offenders with schizophrenia. Supplementary analyses compared the criminal, psychiatric and neuropsychological features of schizophrenic homicide offenders with and without God/Satan/demon-themed psychotic symptoms.

METHODS

Twenty-five men and women diagnosed with schizophrenia who had killed another person - 21 convicted of first-degree murder and 4 found not guilty by reason of insanity - completed neuropsychological testing during forensic evaluations.

RESULTS

The sample was characterised by extensive neurocognitive impairments, involving executive dysfunction (60%), memory dysfunction (68%) and attentional dysfunction (50%), although those with God/Satan/demon-themed psychotic symptoms performed better than those with nonreligious psychotic content.

CONCLUSIONS

Our findings indicate that impaired cognition may play an important role in the commission of homicide by individuals with schizophrenia. A subgroup with God/Satan/demon delusions seem sufficiently less impaired that they might be able to engage in metacognitive treatment approaches, aimed at changing their relationship to their psychotic symptoms, thus reducing the perception of power and omnipotence of hallucinated voices and increasing their safety. Copyright © 2016 John Wiley & Sons, Ltd.

Neuroimaging and Violence

Violence is a serious public health issue across the world. This article assists clinicians in understanding the most up-to-date literature regarding structural and functional brain theories related to risk of violence. In this article, we review anatomic regions of the brain that have been implicated in violence and associated personality constructs associated with violence. We discuss different imaging techniques that have been used to uncover abnormal brain volume, associations, and functions throughout the brain in samples with violence history or risk. Finally, we discuss implications of these findings both for treatment considerations and future research directions.

Objective predictors of outcome in forensic mental health services-a systematic review

This systematic review aimed to examine whether neurobiological methods, or other methods independent of clinical judgment, have been investigated to assist decision making in forensic mental health services and, if so, whether this may be a useful strategy for predicting outcomes. OVID-Medline, Embase, and PsychInfo (inception-January 2015) were searched, limiting to English and human studies, using terms relating to "predict," "outcome," "psychiatry," and "forensic" to identify primary research articles reporting on predictors of outcome in forensic mental health services not reliant on clinical judgment/self-report. Fifty studies investigating demographic, neuropsychological/neurophysiological, and biological predictors were identified, reporting on 3 broad outcomes: (i) inpatient violence, (ii) length of stay, (iii) reoffending. Factors associated positively, negatively, and showing no relationship with each outcome were extracted and compiled across studies. Of various demographic predictors examined, the most consistent associations were between previous psychiatric admissions and inpatient violence; a more "severe" offense and a longer length of stay; and young age and reoffending. Poor performance on tests of cognitive control and social cognition predicted inpatient violence while a neurophysiological measure of impulsivity showed utility predicting reoffending. Serum cholesterol and creatine kinase emerged as biological factors with potential to predict future inpatient violence. Research in this field is in its infancy, but investigations conducted to date indicate that using objective markers is a promising strategy to predict clinically significant outcomes.

Relationship between regional cerebral blood flow and neuropsychiatric symptoms in dementia with Lewy bodies

OBJECTIVE

This aim of this study was to examine the mechanisms underlying the neuropsychiatric symptoms in dementia with Lewy bodies by investigating regional cerebral blood flow.

METHODS

Participants were 27 patients who fulfilled the diagnostic criteria for probable dementia with Lewy bodies. All subjects underwent single-photon emission computed tomography scans using technetium-99 m hexamethylpropyleneamine oxime. Neuropsychiatric symptoms were evaluated by neuropsychiatric inventory. Multiple regression analyses using neuropsychiatric inventory and voxel-based analyses of covariance of the regional cerebral blood flow images between subjects with or without each neuropsychiatric symptom were performed. Additionally, similar voxel-based analyses of covariance between subjects with each neuropsychiatric symptom and normal subjects were performed.

RESULTS

There were no significant correlations in any psychiatric symptoms in multiple regression analyses. All subjects had hallucination but none had euphoria. We analyzed eight neuropsychiatric symptom scores with the exception of hallucination and euphoria using voxel-based analyses of covariance. Significant differences of regional cerebral blood flow were shown in groups with agitation, disinhibition, and irritability. Subjects with agitation showed hypoperfusion in the parietal lobule, the precuneus, and the angular gyrus, and hyperperfusion in the fusiform gyrus, the lingual gyrus, and the thalamus. Subjects with disinhibition showed hypoperfusion in the left frontal gyrus. Subjects with irritability showed hyperperfusion in the right frontal gyrus. There were no significant differences in regional cerebral blood flow between subjects with any neuropsychiatric symptoms and normal subjects.

CONCLUSION

This study reveals that dysfunction of specific brain regions is associated with various neuropsychiatric symptoms in dementia with Lewy bodies.

Posterior Atrophy and Medial Temporal Atrophy Scores Are Associated with Different Symptoms in Patients with Alzheimer's Disease and Mild Cognitive Impairment

Background

Whether the occurrence of posterior atrophy (PA) and medial temporal lobe atrophy (MTA) was correlated with cognitive and non-cognitive symptoms in Alzheimer’s disease (AD) and mild cognitive impairment (MCI) patients are unclear.

Methods

Patients with probable AD and MCI from a medical center outpatient clinic received attention, memory, language, executive function evaluation and Mini-Mental Status Examination (MMSE). The severity of dementia was rated by the Clinical Dementia Rating (CDR) Sum of Box (CDR-SB). The neuropsychiatric inventory (NPI) subscale of agitation/aggression and mood symptoms was also applied. Magnetic resonance imaging (MRI) was scored visually for the MTA, PA and white matter hyperintensity (WMH) scores.

Results

We recruited 129 AD and 31 MCI (mean age 78.8 years, 48% female) patients. MMSE scores, memory, language and executive function were all significantly decreased in individuals with AD than those with MCI (p < 0.01). MTA and PA scores reflected significant atrophy in AD compared to MCI; however, the WMH scores did not differ. The MTA scores were significantly correlated with the frontal, parieto-occipital and global WMH scores (p < 0.01) while the PA scores showed a correlation with the parieto-occipital and temporal WMH scores (p < 0.01). After adjusting for age, education, APOE4 gene and diagnostic group covariates, the MTA scores showed a significant association with MMSE and CDR-SB, while the right side PA scores were significantly associated with NPI-agitation/aggression subscales (p < 0.01).

Conclusion

Regional atrophy is related to different symptoms in patients with AD or MCI. PA score is useful as a complementary measure for non-cognitive symptom.

Deconstructing violence as a medical syndrome: mapping psychotic, impulsive, and predatory subtypes to malfunctioning brain circuits

Violence is a major management issue for forensic mental health systems. Violence can be approached as a medical syndrome and deconstructed into psychotic, impulsive, and predatory subtypes, which are hypothetically mapped onto corresponding malfunctioning brain circuits. Rational management of violence balances treatment with security, while targeting each subtype of violence with approaches unique to the psychotic, impulsive, and predatory forms of violence.

Remember the future II: meta-analyses and functional overlap of working memory and delay discounting

Previously we showed that working memory training decreased the discounting of future rewards in stimulant addicts without affecting a go/no-go task. While a relationship between delay discounting and working memory is consistent with other studies, the unique brain regions of plausible causality between these two abilities have yet to be determined. Activation likelihood estimation meta-analyses were performed on foci from studies of delay discounting (DD = 449), working memory (WM = 452), finger tapping (finger tapping = 450), and response inhibition (RI = 450). Activity maps from relatively less (finger tapping) and more (RI) demanding executive tasks were contrasted with maps of DD and WM. Overlap analysis identified unique functional coincidence between DD and WM. The anterior cingulate cortex was engaged by all tasks. Finger tapping largely engaged motor-related brain areas. In addition to motor-related areas, RI engaged frontal brain regions. The right lateral prefrontal cortex was engaged by RI, DD, and WM and was contrasted out of overlap maps. A functional cluster in the posterior portion of the left lateral prefrontal cortex emerged as the largest location of unique overlap between DD and WM. A portion of the left lateral prefrontal cortex is a unique location where delay discounting and working memory processes overlap in the brain. This area, therefore, represents a therapeutic target for improving behaviors that rely on the integration of the recent past with the foreseeable future.

Lower anterior cingulate volume in seriously violent men with antisocial personality disorder or schizophrenia and a history of childhood abuse

OBJECTIVE

Antisocial personality disorder (ASPD) and schizophrenia, as well as childhood abuse, are associated with violent behaviour and show marked volumetric reduction in the anterior cingulate (AC), a brain region implicated in regulation of violence through its involvement in decision making, empathy, impulse control, and emotion regulation. The present study examined, for the first time to the authors' knowledge, the grey matter volume of the AC in relation to seriously violent behaviour and childhood psychosocial deprivation (including physical and sexual abuse) in the context of a mental disorder (schizophrenia or ASPD).

METHODS

Fifty-seven men [14 with ASPD and a history of serious violence; 13 with schizophrenia and a history of serious violence (VSZ); 15 with schizophrenia without a violence history (SZ); 15 nonviolent healthy participants] underwent whole-brain magnetic resonance imaging and were rated on the presence of physical abuse, sexual abuse, neglect, extreme poverty, foster home placement, criminal parent, severe family conflict, and broken home (collectively 'psychosocial deprivation'). Stereological volumetric ratings of the AC were examined for group differences and their association with childhood psychosocial deprivation.

RESULTS

A higher proportion of ASPD and VSZ patients had suffered psychosocial deprivation as children, in particular severe physical abuse, relative to SZ patients and healthy participants. ASPD and VSZ, but not SZ, patients had significantly lower AC volume relative to healthy participants. AC volumes correlated negatively with (total) psychosocial deprivation as well as physical and sexual abuse ratings. Group differences in AC volume became nonsignificant when psychosocial deprivation ratings were covaried for.

CONCLUSIONS

Violent mentally disordered individuals with ASPD or schizophrenia suffer from a significant AC volume loss and this deficit, at least in part, is explained by their histories of stressful childhood experiences. Current and future therapies aiming to reduce violence in such populations would benefit by attending to biological (and other) correlates of childhood abuse.

Neurocognitive vulnerability: suicidal and homicidal behaviours in patients with schizophrenia

OBJECTIVE

Schizophrenia is associated with an increase in the risk of both homicide and suicide. The objectives of this study were to systematically review all published articles that examined the relation between neurocognitive deficits and suicidal or homicidal behaviours in schizophrenia, and to identify vulnerabilities in suicidal and homicidal behaviour that may share a common pathway in schizophrenia.

METHODS

A systematic review of the literature was performed using MEDLINE to include all studies published up to August 31, 2012.

RESULTS

Among the 1760 studies, 7 neuropsychological and 12 brain imaging studies met the selection criteria and were included in the final analysis. The neuropsychological and functional neuroimaging studies were inconclusive. The structural imaging studies reported various alterations in patients with schizophrenia and a history of homicidal behaviour, including: reduced inferior frontal and temporal cortices, increased mediodorsal white matter, and increased amygdala volumes. Patients with a history of suicidal acts showed volumetric reductions in left orbitofrontal and superior temporal cortices, while right amygdala volume was increased, though, these findings have rarely been replicated. Finally, no study has directly compared neurocognitive markers of suicidal and homicidal risk.

CONCLUSION

These results suggest that brain alterations, in addition to those associated with schizophrenia, may predispose some patients to a higher risk of homicide or suicide in particular circumstances. Moreover, some of these alterations may be shared between homicidal and suicidal patients. However, owing to several limitations, including the small number of available studies, no firm conclusions can be drawn and further investigations are necessary.

Meta-analytic evidence for a superordinate cognitive control network subserving diverse executive functions

Classic cognitive theory conceptualizes executive functions as involving multiple specific domains, including initiation, inhibition, working memory, flexibility, planning, and vigilance. Lesion and neuroimaging experiments over the past two decades have suggested that both common and unique processes contribute to executive functions during higher cognition. It has been suggested that a superordinate fronto-cingulo-parietal network supporting cognitive control may also underlie a range of distinct executive functions. To test this hypothesis in the largest sample to date, we used quantitative meta-analytic methods to analyze 193 functional neuroimaging studies of 2,832 healthy individuals, ages 18-60, in which performance on executive function measures was contrasted with an active control condition. A common pattern of activation was observed in the prefrontal, dorsal anterior cingulate, and parietal cortices across executive function domains, supporting the idea that executive functions are supported by a superordinate cognitive control network. However, domain-specific analyses showed some variation in the recruitment of anterior prefrontal cortex, anterior and midcingulate regions, and unique subcortical regions such as the basal ganglia and cerebellum. These results are consistent with the existence of a superordinate cognitive control network in the brain, involving dorsolateral prefrontal, anterior cingulate, and parietal cortices, that supports a broad range of executive functions.

Reduced thalamic volume in men with antisocial personality disorder or schizophrenia and a history of serious violence and childhood abuse

OBJECTIVE

Violent behaviour has been associated with presence of certain mental disorders, most notably antisocial personality disorder (ASPD) and schizophrenia, childhood abuse, and multiple brain abnormalities. This study examined for the first time, to the authors' knowledge, the role of psychosocial deprivation (PSD), including childhood physical and sexual abuse, in structural brain volumes of violent individuals with ASPD or schizophrenia.

METHODS

Fifty-six men (26 with ASPD or schizophrenia and a history of serious violence, 30 non-violent) underwent magnetic resonance imaging and were assessed on PSD. Stereological volumetric brain ratings were examined for group differences and their association with PSD ratings. PSD-brain associations were examined further using voxel-based-morphometry.

RESULTS

The findings revealed: reduced thalamic volume in psychosocially-deprived violent individuals, relative to non-deprived violent individuals and healthy controls; negative association between thalamic volume and abuse ratings (physical and sexual) in violent individuals; and trend-level negative associations between PSD and hippocampal and prefrontal volumes in non-violent individuals. The voxel-based-morphometry analysis detected a negative association between PSD and localised grey matter volumes in the left inferior frontal region across all individuals, and additionally in the left middle frontal and precentral gyri in non-violent individuals.

CONCLUSIONS

Violent mentally-disordered individuals with PSD, relative to those with no or minimal PSD, suffer from an additional brain deficit, i.e., reduced thalamic volume; this may affect sensory information processing, and have implications for management, of these individuals. PSD may have a stronger relationship with volumetric loss of stress-linked regions, namely the frontal cortex, in non-violent individuals.

Publication bias in neuroimaging research: implications for meta-analyses

Neuroimaging and the neurosciences have made notable advances in sharing activation results through detailed databases, making meta-analysis of the published research faster and easier. However, the effect of publication bias in these fields has not been previously addressed or accounted for in the developed meta-analytic methods. In this article, we examine publication bias in functional magnetic resonance imaging (fMRI) for tasks involving working memory in the frontal lobes (Brodmann Areas 4, 6, 8, 9, 10, 37, 45, 46, and 47). Seventy-four studies were selected from the literature and the effect of publication bias was examined using a number of regression-based techniques. Pearson's r correlation coefficient and Cohen's d effect size estimates were computed for the activation in each study and compared to the study sample size using Egger's regression, Macaskill's regression, and the 'Trim and Fill' method. Evidence for publication bias was identified in this body of literature (p < 0.01 for each test), generally, though was neither task- nor sub-region-dependent. While we focused our analysis on this subgroup of brain mapping studies, we believe our findings generalize to the brain imaging literature as a whole and databases seeking to curate their collective results. While neuroimaging databases of summary effects are of enormous value to the community, the potential publication bias should be considered when performing meta-analyses based on database contents.

Neurobiology of aggression and violence in schizophrenia

There is much evidence that schizophrenia patients have an increased risk for aggression and violent behavior, including homicide. The neurobiological basis and correlates of this risk have not been much studied. While genome-wide association studies are lacking, a number of candidate genes have been investigated. By far, the most intensively studied is the catechol-O-methyltransferase (COMT) gene on chromosome 22. COMT is involved in the metabolism of dopamine, a key neurotransmitter in schizophrenia pathophysiology. Several studies suggest that the Val158Met polymorphism of this gene affects COMT activity. Methionine (Met)/Met homozygote schizophrenia patients show 4- to 5-fold lower COMT activity than valine (Val)/Val homozygotes, and some but not all studies have found an association with aggression and violence. Recently, a new functional single-nucleotide polymorphism in the COMT gene, Ala72Ser, was found to be associated with homicidal behavior in schizophrenia, but this finding warrants further replication. Studies published so far indicate that an association with the monoamine oxidase A, B, or tryptophan hydroxylase 1 genes is unlikely. Data for the brain-derived neurotrophic factor gene are conflicting and limited. Data from the limited number of neuroimaging studies performed to date are interesting. Frontal and temporal lobe abnormalities are found consistently in aggressive schizophrenia patients. Positron emission tomography and single photon-emission computed tomography (SPECT) data indicate deficits also in the orbitofrontal and temporal cortex. Some functional magnetic resonance imaging studies found a negative association of violent behavior with frontal and right-sided inferior parietal activity. Neuroimaging studies may well help further elucidate the interrelationship between neurocognitive functioning, personality traits, and antisocial and violent behavior.

Dorsolateral prefrontal cortex activity predicts responsiveness to cognitive-behavioral therapy in schizophrenia

BACKGROUND

Given the variable response to cognitive-behavioral therapy (CBT) when added to antipsychotic medication in psychosis and the evidence for a role of pretherapy level of frontal lobe-based cognitive function in responsiveness to CBT in other disorders, this study examined whether pretherapy brain activity associated with working memory neural network predicts clinical responsiveness to CBT in schizophrenia.

METHODS

Fifty-two outpatients stable on medication with at least one distressing symptom of schizophrenia and willing to receive CBT in addition to their usual treatment and 20 healthy participants underwent functional magnetic resonance imaging during a parametric n-back task. Subsequently, 26 patients received CBT for psychosis (CBT+treatment-as-usual [TAU], 19 completers) for 6-8 months, and 26 continued with TAU alone (17 completers). Symptoms in both patient groups were assessed (blindly) at entry and follow-up.

RESULTS

The CBT+TAU and TAU-alone groups did not differ clinically or in performance at baseline. The CBT+TAU group showed significant improvement in relation to the TAU-alone group, which showed no change, at follow-up. Stronger dorsolateral prefrontal cortex (DLPFC) activity (within the normal range) and DLPFC-cerebellum connectivity during the highest memory load condition (2-back > 0-back) were associated with post-CBT clinical improvement.

CONCLUSIONS

DLPFC activity and its connectivity with the cerebellum predict responsiveness to CBT for psychosis in schizophrenia. These effects may be mediated by PFC-cerebellum contributions to executive processing.

Dysfunctional, but not functional, impulsivity is associated with a history of seriously violent behaviour and reduced orbitofrontal and hippocampal volumes in schizophrenia

Aggression and violent acts have been linked with impulsive responding. We investigated whether impulsive personality trait, especially suggestive of dysfunctional impulsivity (i.e. fast and inaccurate responding where this is non-optimal), is associated with a history of seriously violent behaviour and specific brain deficits in schizophrenia. Twenty-four male participants with schizophrenia, of whom 10 had a history of serious physical violence, and 14 healthy male participants were assessed on impulsiveness (dysfunctional impulsivity), venturesomeness (functional impulsivity), and empathy. All participants underwent magnetic resonance imaging. The results revealed that participants with schizophrenia and a history of violence showed elevated impulsiveness but had comparable scores on venturesomeness and empathy dimensions. Impulsiveness scores correlated negatively with reduced orbitofrontal grey matter volume in both the patient and healthy control groups, and with hippocampal volume in the patient group. Our findings suggest that dysfunctional, but not functional, impulsivity is elevated in patients with schizophrenia with a propensity for repetitive violence, and this in turn appears to be associated with reduce volumes of both the orbitofrontal cortex grey matter and the hippocampus. Violence risk prediction and management strategies in schizophrenia may benefit from including specific measures of dysfunctional impulsive traits.

Aggression, psychopathy and brain imaging - Review and future recommendations

Violent behavior appears to result from a complex web of interacting genetic as well as environmental factors. Psychopathy is a strong predictor for relapse in violent acts. The current review shed light on rapidly expanding knowledge in brain imaging related to violent behavior and psychopathy. A literature search was performed in PubMed, Cochrane and PsycInfo combining the key words: mentally disordered offender/aggression/violence/ crime/forensic psychiatry/brain imaging neuroimaging/fMRI/MRI/PET/SPECT/lack of empathy/psychopathy and antisocial personality disorder. The reviewed material, which consisted of 48 articles, indicates a rather strong consensus on the connection between dysfunctional parts of the frontal and temporal lobes and violent antisocial behavior and psychopathy. In future studies, it would be useful to focus on the limbic system and to investigate which parts of the frontal lobes and cerebral networks that are of interest in the psychopathic personality. Moreover, the reviewed material highlights some of the methodological difficulties in this area of research such as selection bias in the recruitment of patients, inadequate matching of control subjects, and sometimes incongruous results. In the future we hope that brain imaging can be used to map biological deviations in different offenders in order to try to learn more about the different mechanisms behind violent behaviors.

Neural and behavioural responses to threat in men with a history of serious violence and schizophrenia or antisocial personality disorder

BACKGROUND

Contemporary theories and evidence implicate defective emotion regulation in violent behaviour. The two psychiatric illnesses most implicated in violence are schizophrenia and antisocial personality disorder (APD). This study examined behavioural and brain abnormalities in violent men with schizophrenia or APD during anticipatory fear.

METHOD

Fifty-three men [14 non-violent healthy controls, 13 with schizophrenia and a history of serious violence (VSZ), 13 with schizophrenia without a history of violence (SZ), 13 with APD and a history of serious violence] underwent blood-oxygenation-level-dependent fMRI during an experiment involving repeated presentations of 'safe' and 'threat of electric shock' conditions and provided ratings of shock anticipation and fear. Schizophrenia patients did not have co-morbid APD.

RESULTS

VSZ participants reported the highest, and APD participants the lowest, level of shock anticipation and fear, with intermediate ratings by SZ and healthy participants. The violent, relative to non-violent, groups showed altered activity modulation in occipital and temporal regions, from early to latter parts of threat periods. Additionally, VSZ patients displayed exaggerated whereas APD patients showed attenuated thalamic-striatal activity during latter threat periods.

CONCLUSIONS

Aberrant activity in occipital and temporal regions when exposed to sustained visual threat cues is associated with a predisposition to violence in both schizophrenia and APD. This common biological deficit, however, appears to arise from dissimilar behavioural mechanisms related to differences in the strength of aversive conditioning and behavioural response to sustained threat cues (enhanced in VSZ; attenuated in APD), also reflected in opposite patterns of alternations in thalamic-striatal activity, in these two disorders.

A multivariate approach to aggression and the orbital frontal cortex in psychiatric patients

The association between orbital frontal cortex (OFC) volume and aggression was investigated in an at-risk psychiatric population. Forty-one psychiatric patients were referred for magnetic resonance imaging and a standardized psychometric assessment of aggression (Lifetime History of Aggression-Revised). Nineteen matched controls had lower levels of aggression and greater OFC volume, establishing the appropriateness of the psychiatric group for studying aggression pathophysiology. Consistent with study hypotheses, left OFC gray matter volume predicted 34% of the variance in self-reported aggression ratings. When impulsivity was not controlled for, left OFC gray matter only accounted for 26% of aggression variance, suggesting a complex relationship between impulsivity and OFC-aggression pathophysiology. Contrary to study hypotheses, right OFC gray matter volume did not predict degree of aggressive behavior. Current models do not account for lateralization, yet this may be quite important. Greater consideration should be given to laterality in OFC regulation of social/emotional behavior. Regulatory focus theory, positing two motivational systems, promotion and prevention, lateralized to the left and right hemispheres, respectively, may provide an explanatory framework for these results. Dysregulation of the left hemisphere 'promotion' motivational system may help to explain the aggressive behavior present in psychiatric populations.

Psychosis and violence: stories, fears, and reality

Individuals with psychosis are often feared. In fact, they are themselves likely to be victims of violence; however, the main aim of this review is to provide an overview of the evidence on relations between psychosis and violence to others. The terms psychosis and violence were used in a literature search limited to the Cochrane Library and PubMed, a manual search of 8 journals, and a follow-up of additional references in the articles found. The overview draws on new empirical data and major reviews. Almost all sound epidemiologic data on psychosis and violence dates from 1990. There is consistency on a small but significant relation between schizophrenia and violent acts. Since then there has also been movement toward understanding the nature of associations and progress on strategies for managing individuals who have psychosis and are violent. Public fears about individuals with psychotic illnesses are largely unfounded, although there would be benefit in greater attention to the safety of those in their close social circle. The task for the next 10 years must be the development and application of knowledge to improve specific treatments-that is, interventions that go beyond holding and caring to bring about substantial change.

Neurobiology and the development of violence: common assumptions and controversies

This paper addresses four common assumptions and related controversies regarding neurobiological factors explaining violence: (i) scholars often assume stability of individual differences in neurobiological factors pertaining to violence, yet much change occurs in aggression/violence during the life course, (ii) individual differences in aggression/violence reflect one or more underlying mechanisms that are believed to have neurobiological origins, yet there is little agreement about which underlying mechanisms apply best, (iii) the development of aggression/violence to some degree can be explained by social, individual, economic and environmental factors, yet it is unclear to what extent neurobiological factors can explain the escalation to, and desistance from, violence over and above social, individual, economic and environmental factors, and (iv) violence waxes and wanes in society over time, yet the explanation of secular differences in violence by means of neurobiological and other factors is not clear. Longitudinal analyses from the Pittsburgh Youth Study are used to illustrate several of these issues.

A magnetic resonance spectroscopy study of antisocial behaviour disorder, psychopathy and violent crime among military conscripts

BACKGROUND

Prefrontal and/or temporo-limbic abnormalities associated with antisocial personality disorder (APD), high psychopathy scores and violent behaviours can readily be evaluated by neuroimaging methods.

OBJECTIVES

In this study, we compared the brain metabolites in adult male military conscripts with APD, high psychopathy scores and serious violent crimes (n = 15) with age- and educational-level-matched healthy controls (n = 15) by means of magnetic resonance spectroscopy.

METHODS

All cases were diagnosed by means of the Diagnostic Statistical Manual-IV APD module of the Structured Clinical Interview for DSM III-R Axis II Disorders (SCID-II) semistructured questionnaire in Turkish. The psychopathy scores were evaluated by means of the Hare Psychopathy Checklist-Revised translated into Turkish (PCL-R). PCL-R is a 20-item, reliable and valid instrument for assessment of psychopathy, both in categorical and dimensional natures. All patients had a total score of 29 (of possible 40) or higher from PCL-R, indicating a high degree of psychopathy.

RESULTS

Our results showed no significant differences in ratio of N-acetyl aspartate (NAA), creatine (Cr) and choline-related compounds in the right dorsolateral prefrontal cortex, anterior cingulate cortex (ACC) and amygdala-hippocampus regions of cases compared with controls. ACC NAA/Cr was significantly negatively correlated with both the PCL-R total score and the PCL-R factor I score (interpersonal/affective problems) among the cases.

CONCLUSION

As ACC plays an important role in decision-making and emotional information processing, we postulate that the lower NAA/Cr ratio, suggesting impaired neural integrity, may increase the severity of interpersonal/affective problems of the psychopathy factor in male subjects exhibiting APD, high psychopathy overall scores and violent crimes.

Neural correlates of deficient response inhibition in mentally disordered violent individuals

In this study, response inhibition and associated neural activation during a motor inhibition paradigm were investigated in (i) men with antisocial personality disorder (APD) with a history of violence (n = 14), (ii) men with schizophrenia with a history of violence (n = 12), (iii) men with schizophrenia without a history of violence (n = 12), and (iv) healthy control subjects (n = 14) using functional magnetic resonance imaging (fMRI). At the behavioural level, individuals with schizophrenia showed impaired performance across all conditions, whereas an increased error rate was seen in the APD group only during the conditions requiring inhibition. At the neural level, both violent groups showed reduced thalamic activity, compared with controls, in association with modulation of inhibition by task demands. In addition, the violent schizophrenia group, compared with controls, showed reduced activity in the caudate nucleus during the condition requiring inhibition. It is concluded that violence may not be specifically associated with impaired voluntary inhibition in schizophrenia but this is likely in APD. Reduced thalamic function, perhaps due to its known association with sensorimotor disturbances, is implicated in violent behaviour across both disorders. In addition, caudate dysfunction may contribute, given its role in timing and temporal processing as well as suppression of motor actions, to deficient inhibition and violent behaviour in schizophrenia.

The P50 auditory evoked potential in violent and non-violent patients with schizophrenia

BACKGROUND

Emotionally driven violence is facilitated by increased arousal. It may be a consequence of an information-processing deficit and the cognitive attributions for the stimuli given by the subject. The aim of this study was to compare the P50 evoked potential responses of violent patients with schizophrenia with non-violent patients with schizophrenia and healthy controls.

METHOD

Patients were classified into violent and non-violent in accordance to the Overt Aggression Scale. P50 auditory evoked potentials of 32 unmedicated patients with schizophrenia (violent=14, non-violent=18) and 17 healthy controls were recorded during five runs of 30 click pairs.

RESULTS

Healthy controls exhibited a lower S2/S1 ratio when compared to violent (p<0.001) and non-violent (p=0.04) patients. Using a cutoff point of 0.50 for S2/S1 ratio to define abnormal gating a significant proportion of violent patients did not show P50 suppression (71.4%) in comparison to non-violent patients (38.9%) and healthy controls (23.5%) (p=0.02).

CONCLUSIONS

Violent behavior in patients with schizophrenia could be associated with a disturbed information sensory gating. Violence in patients with schizophrenia may be facilitated by an increased arousal which may in turn be the result of an information-processing deficit.

Regional cortical thinning in subjects with violent antisocial personality disorder or schizophrenia

Violent behavior is associated with antisocial personality disorder and to a lesser extent with schizophrenia. Neuroimaging studies have suggested that several biological systems are disturbed in schizophrenia, and structural changes in frontal and temporal lobe regions are reported in both antisocial personality disorder and schizophrenia. The neural substrates that underlie violent behavior specifically and their structural analogs, however, remain poorly understood. Nor is it known whether a common biological basis exists for aggressive, impulsive, and violent behavior across these clinical populations. To explore the correlates of violence with brain structure in antisocial personality disorder and schizophrenia, the authors used magnetic resonance imaging data to investigate for the first time, to the authors' knowledge, regional differences in cortical thickness in violent and nonviolent individuals with schizophrenia and/or antisocial personality disorder and in healthy comparison subjects. Subject groups included right-handed men closely matched for demographic variables (total number of subjects=56). Violence was associated with cortical thinning in the medial inferior frontal and lateral sensory motor cortex, particularly in the right hemisphere, and surrounding association areas (Brodmann's areas 10, 11, 12, and 32). Only violent subjects with antisocial personality disorder exhibited cortical thinning in inferior mesial frontal cortices. The biological underpinnings of violent behavior may therefore vary between these two violent subject groups in which the medial frontal cortex is compromised in antisocial personality disorder exclusively, but laminar abnormalities in sensorimotor cortices may relate to violent behavior in both antisocial personality disorder and schizophrenia.

Disorders of arousal from sleep and violent behavior: the role of physical contact and proximity

STUDY OBJECTIVES

To review medical and legal case reports to determine how many appear to support the belief that violence against other individuals that occurs during Disorders of Arousal - sleepwalking, confusional arousal, and sleep terrors - is triggered by direct physical contact or close proximity to that individual and does not occur randomly or spontaneously.

DESIGN

Historical review of case reports in the medical and legal literature.

MEASUREMENTS AND RESULTS

A total of 32 cases drawn from medical and legal literature were reviewed. Each case contained a record of violence associated with Disorders of Arousal; in each, details of the violent behavior were available. Violent behaviors associated with provocations and/or close proximity were found to be present in 100% of confusional arousal patients and 81% of sleep terror patients. Violent behaviors were associated with provocation or close proximity in 40%-90% of sleepwalking cases, depending on whether the legal verdict and other factors were taken into account. Often the provocation was quite minor and the response greatly exaggerated. The specific manner in which the violence was triggered differed among sleepwalking, confusional arousals, and sleep terrors.

CONCLUSIONS

In the cases reviewed, violent behavior directed against other individuals associated with Disorders of Arousal most frequently appeared to follow direct provocation by, or close proximity to, another individual. Sleepwalkers most often did not seek out victims, but rather the victims sought out or encountered the sleepwalker. These conclusions are tempered by several limitations: the selection of cases was not random and may not represent an accurate sample of violent behaviors associated with Disorders of Arousal. Also, final verdicts by juries in reported legal cases should not be confused with scientific proof of the presence or absence of sleepwalking. The pathophysiology of Disorders of Arousal with and without violent behavior could be associated with normally occurring deactivation of the frontal lobes during slow wave sleep (SWS) connected via atypically active thalamocortical pathways to the limbic areas. It is not known if the violent sleepwalker, confusional arousal patient, or sleep terror patient differs from other patients with these disorders. The conclusions of this case series await confirmation by the results of future sleep laboratory based studies.

Violent persons with schizophrenia and comorbid disorders: a functional magnetic resonance imaging study

The main goal of this functional Magnetic Resonance Imaging (fMRI) study was to verify the hypothesis that seriously violent persons with Sz and the co-morbid diagnoses of an Antisocial Personality Disorder (APD) and a Substance Use Disorder (Sz+APD+SUD) would present a different pattern of prefrontal functioning than seriously violent persons with Sz only. In support with the main hypothesis, frontal basal cortices were significantly less activated in persons with Sz+APD+SUD during the execution of a go/no-go task than in persons with Sz only and non-violent persons without a mental illness. In contrast, significantly higher activations in frontal motor, premotor and anterior cingulate regions were observed in the Sz+APD+SUD group than in the Sz-only group.