Personality disorder symptomatology is associated with anomalies in striatal and prefrontal morphology

The neurobiology of obsessive-compulsive personality disorder: a systematic review

BACKGROUND

A number of recent investigations have focused on the neurobiology of obsessive-compulsive personality disorder (OCPD). However, there have been few reviews of this literature with no detailed model proposed. We therefore undertook a systematic review of these investigations, aiming to map the available evidence and investigate whether it is possible to formulate a detailed model of the neurobiology of OCPD.

METHODS

OCPD can be considered from both categorical and dimensional perspectives. An electronic search was therefore conducted using terms that would address not only OCPD as a category, but also related constructs, such as perfectionism, that would capture research on neuropsychology, neuroimaging, neurochemistry, and neurogenetics.

RESULTS

A total of 1059 articles were retrieved, with 87 ultimately selected for abstract screening, resulting in a final selection of 49 articles focusing on neurobiological investigations relevant to OCPD. Impaired executive function and cognitive inflexibility are common neuropsychological traits in this condition, and suggest that obsessive-compulsive disorder (OCD) and OCPD may lie on a continuum. However, neuroimaging studies in OCPD indicate the involvement of specific neurocircuitry, including the precuneus and amygdala, and so suggest that OCD and OCPD may have important differences. Although OCPD has a heritable component, we found no well-powered genetic studies of OCPD.

CONCLUSION

Although knowledge in this area has advanced, there are insufficient data on which to base a comprehensive model of the neurobiology of OCPD. Given the clinical importance of OCPD, further work to understand the mechanisms that underpin this condition is warranted.

Do comorbid personality disorders in cocaine dependence exacerbate neuroanatomical alterations? A structural neuroimaging study

Cocaine dependence (CD) is highly comorbid with personality disorders, with implications for poorer treatment response. The neurobiological mechanisms of this comorbidity are unclear. We aimed to test the role of comorbid personality disorders in the neuroanatomy of CD. We examined 4 groups using high-resolution structural neuroimaging, psychological questionnaires and cognitive tests: CD (n = 19), CD and personality disorder type B (CD + B, n = 21), CD and personality disorder C (CD + C, n = 13) and 21 controls. We compared groups in neuroanatomy and hypothesised that (i) CD would show altered striatal areas ascribed to reward processing (i.e., accumbens, caudate and putamen), (ii) CD + B and CD + C would show altered areas supporting emotional regulation/social valuation and anxiety/avoidance (i.e., OFC and amygdala). The CD + B group had larger caudate volumes than CD (p = .01, d = 0.94) and reduced lateral OFC thickness than CD + C (p = .056, d = 0.71). Exploratory correlations showed that altered neural integrity of the OFC and of the caudate nucleus in these groups exacerbated with worse personality disorder severity and impulsivity scores. CD with and without comorbid personality disorders may have partially distinct underlying mechanisms and targets for treatment.

Personality and psychiatric disorders in chronic pain male affected by erectile dysfunction: prospective and observational study

The prevalence of personality disorders (PDs) and sexual dysfunction in chronic pain patients is higher than in general population. Our main objective was to analyse the influence of PD in patients with erectile dysfunction and chronic non-cancer pain and their response to andrological treatment. One-hundred one patients were included along 30 months. Pain intensity, quality of life, sexual life quality, anxiety and depression were analysed together with opioid dose. Erectile functioning was measured with the International Index of Erectile Function (IIEF) and PDs with Millon Clinical Multiaxial Inventory (MCMI-III). The mean age was 57 ± 12 years old, with moderate to severe pain, 70% were sexually active and presented moderate to severe ED. PDs were very frequent (31%, cut-off 85 and 84% cut-off 75 scores) mostly anxiety, compulsive, though disorder, somatoform and narcissistic. Self-defeating feature presence was significantly correlated (r = -0.4, 95% CI = -0.605 to -0.145, p = 0.002) with a more severe baseline ED and narcissistic, and a better response to andrological treatment (p = 0.010, d = 1.082). Patients with dysthymia features required significantly higher opioid doses vs. control (238 vs. 102 mg/day, respectively). These findings underline the importance of diagnosing PDs to rigorously treat patients with chronic pain and ED.

Nucleus accumbens shell small conductance potassium channels underlie adolescent ethanol exposure-induced anxiety

Alcohol use typically begins in adolescence, increasing the likelihood of adult mental disorders such as anxiety. However, the cellular mechanisms underlying the consequences of adolescent alcohol exposure as well as the behavioral consequences remain poorly understood. We examined the effects of adolescent or adult chronic intermittent ethanol (CIE) exposure on intrinsic excitability of striatal medium-sized spiny neurons (MSNs) and anxiety levels. Rats underwent one of the following procedures: (1) light-dark transition (LDT) and open-field (OF) tests to evaluate anxiety levels and general locomotion; (2) whole-cell patch clamp recordings and biocytin labeling to assess excitability of striatal MSNs, as well as morphological properties; and (3) western blot immunostaining to determine small conductance (SK) calcium-activated potassium channel protein levels. Three weeks, but not 2 days, after CIE treatment, adolescent CIE-treated rats showed shorter crossover latency from the light to dark side in the LDT test and higher MSN excitability in the nucleus accumbens shell (NAcS). Furthermore, the amplitude of the medium afterhyperpolarization (mAHP), mediated by SK channels, and SK3 protein levels in the NAcS decreased concomitantly. Finally, increased anxiety levels, increased excitability, and decreased amplitude of mAHP of NAcS MSNs were reversed by SK channel activator 1-EBIO and mimicked by the SK channel blocker apamin. Thus, adolescent ethanol exposure increases adult anxiety-like behavior by downregulating SK channel function and protein expression, which leads to an increase of intrinsic excitability in NAcS MSNs. SK channels in the NAcS may serve as a target to treat adolescent alcohol binge exposure-induced mental disorders, such as anxiety in adulthood.

Personality patterns of people with medically refractory epilepsy - Does the epileptogenic zone matter?

OBJECTIVES

The aims of this study were to determine the rate of dysfunctional personality patterns before and after epilepsy surgery, their types, and the importance of the epileptogenic zone in a sample of people with refractory epilepsy.

METHODS

We conducted an ambispective observational study, including refractory epilepsy surgery candidates. Demographic, psychiatric, and neurological data were recorded. Evaluation of personality was made using the Millon Clinical Multiaxial Inventory-II (MCMI-II). Presurgical predictors of personality patterns were determined using a linear regression model. The proportion of patients with dysfunctional personality patterns, before and after surgery, was compared using the Mcnemar's test. Then a generalized estimating equation model was performed to include predictors of changes in this rate.

RESULTS

One hundred and ninety-nine participants were included. Seventy percent had a dysfunctional personality pattern before surgery. After surgery, this percentage dropped to 58%. The difference was statistically significant after adjusting for potential confounders (p = 0.013). The most common types were Cluster C personality patterns. Temporal epileptogenic zone was a significant predictor of higher scores of the Avoidant (Coef. 11.8; Confidence Interval (CI) -0.59 23.7; p = 0.051) and Compulsive (Coef. 9.55; CI 2.48 16.6; p = 0.008) personality patterns and lower scores of Histrionic (Coef. -11.4; CI -21.2 -1.55; p = 0.024) and Antisocial (Coef. -8.4; CI -15.6 -1.25; p = 0.022) personality patterns, compared to extratemporal epileptogenic zone.

CONCLUSION

People with refractory epilepsy have high rates of dysfunctional personality patterns. These patterns differ according to the epileptogenic zone.

Volumetric MRI study of orbito-frontal cortex and thalamus in obsessive-compulsive personality disorder

OBJECTIVES

Obsessive compulsive personality disorder (OCPD) is currently thought to bear a close relationship with obsessive-compulsive disorder (OCD), and other compulsive disorders such as eating disorder and autistic spectrum disorder, as well as with the personality disorders, focusing on some important dimensions like phenomenology, heritability, environmental risk factors, comorbidity, course of illness, neurocognitive endophenotypes, and treatment response. In the present study, when we have taken into consideration the knowledge aforementioned, we aimed to examine OFC and thalamus volumes in patients with OCPD.

METHODS

We comparatively measured orbito-frontal cortex (OFC) and thalamus volumes of patients with OCPD and healthy control subjects.

RESULTS

Patients with OCPD had considerably smaller left and right OFC volumes compared to those of healthy control subjects. We also found that thalamus volumes of patients were statistically significantly greater than those of healthy comparisons for both sides of region of interest.

CONCLUSIONS

We consider that volumetric alterations determined in the present study may be involved in the pathophysiology of the OCPD, considering that OCPD might be related to OCD spectrum disorders neuroanatomically.

Association of monoamine oxidase-A genetic variants and amygdala morphology in violent offenders with antisocial personality disorder and high psychopathic traits

Violent offending is elevated among individuals with antisocial personality disorder (ASPD) and high psychopathic traits (PP). Morphological abnormalities of the amygdala and orbitofrontal cortex (OFC) are present in violent offenders, which may relate to the violence enacted by ASPD + PP. Among healthy males, monoamine oxidase-A (MAO-A) genetic variants linked to low in vitro transcription (MAOA-L) are associated with structural abnormalities of the amygdala and OFC. However, it is currently unknown whether amygdala and OFC morphology in ASPD relate to MAO-A genetic polymorphisms. We studied 18 ASPD males with a history of violent offending and 20 healthy male controls. Genomic DNA was extracted from peripheral leukocytes to determine MAO-A genetic polymorphisms. Subjects underwent a T1-weighted MRI anatomical brain scan that provided vertex-wise measures of amygdala shape and surface area and OFC cortical thickness. We found that ASPD + PP subjects with MAOA-L exhibited decreased surface area in the right basolateral amygdala nucleus and increased surface area in the right anterior cortical amygdaloid nucleus versus healthy MAOA-L carriers. This study is the first to describe genotype-related morphological differences of the amygdala in a population marked by high aggression. Deficits in emotional regulation that contribute to the violence of ASPD + PP may relate to morphological changes of the amygdala under genetic control.

Neuroanatomical and Symptomatic Sex Differences in Individuals at Clinical High Risk for Psychosis

Sex differences have been widely observed in clinical presentation, functional outcome and neuroanatomy in individuals with a first-episode of psychosis, and chronic patients suffering from schizophrenia. However, little is known about sex differences in the high-risk stages for psychosis. The present study investigated sex differences in cortical and subcortical neuroanatomy in individuals at clinical high risk (CHR) for psychosis and healthy controls (CTL), and the relationship between anatomy and clinical symptoms in males at CHR. Magnetic resonance images were collected in 26 individuals at CHR (13 men) and 29 CTLs (15 men) to determine total and regional brain volumes and morphology, cortical thickness, and surface area (SA). Clinical symptoms were assessed with the brief psychiatric rating scale. Significant sex-by-diagnosis interactions were observed with opposite directions of effect in male and female CHR subjects relative to their same-sex controls in multiple cortical and subcortical areas. The right postcentral, left superior parietal, inferior parietal supramarginal, and angular gyri [<5% false discovery rate (FDR)] were thicker in male and thinner in female CHR subjects compared with their same-sex CTLs. The same pattern was observed in the right superior parietal gyrus SA at the regional and vertex level. Using a recently developed surface-based morphology pipeline, we observed sex-specific shape differences in the left hippocampus (<5% FDR) and amygdala (<10% FDR). Negative symptom burden was significantly higher in male compared with female CHR subjects (p = 0.04) and was positively associated with areal expansion of the left amygdala in males (<5% FDR). Some limitations of the study include the sample size, and data acquisition at 1.5 T. This study demonstrates neuroanatomical sex differences in CHR subjects, which may be associated with variations in symptomatology in men and women with psychotic symptoms.

Genetic and Neuroimaging Features of Personality Disorders: State of the Art

Personality disorders often act as a common denominator for many psychiatric problems, and studies on personality disorders contribute to the etiopathology, diagnosis, and treatment of many mental disorders. In recent years, increasing evidence from various studies has shown distinctive features of personality disorders, and that from genetic and neuroimaging studies has been especially valuable. Genetic studies primarily target the genes encoding neurotransmitters and enzymes in the serotoninergic and dopaminergic systems, and neuroimaging studies mainly focus on the frontal and temporal lobes as well as the limbic-paralimbic system in patients with personality disorders. Although some studies have suffered due to unclear diagnoses of personality disorders and some have included few patients for a given personality disorder, great opportunities remain for investigators to launch new ideas and technologies in the field.