Impulsivity in personality disorders: current views and future directions

The association of impulsivity with depression and anxiety symptoms: A transdiagnostic network analysis and replication

BACKGROUND

Impulsivity increases the risk for depression and anxiety. However, the granular pathways among them remain unknown. A network approach that moves from disorder-level analysis to symptom-level analysis can provide further understanding of psychopathological mechanisms. In this study, we examined the network structure of impulsivity and separate and comorbid symptoms of depression and anxiety.

METHODS

Regularized partial-correlation networks were estimated using cross-sectional data from 1047 Chinese participants aged 18-26 years (main dataset, mean age = 21.45 ± 2.01 years) and 325 Chinese participants aged 18-36 years (an independent replication dataset, mean age = 21.49 ± 3.73 years), including impulsivity-depression, impulsivity-anxiety, and impulsivity-depression-anxiety networks. The datasets were collected from 1 June 2023 to 4 August 2023 and from 27 April 2022 to 16 May 2022, respectively. Impulsivity, depression, and anxiety were assessed using Barratt Impulsiveness Scale Version 11, Patient Health Questionnaire-9, and Generalized Anxiety Disorder-7, respectively. Bridge centrality was analyzed, and a network comparison test (NCT) was conducted to investigate the differences between the main dataset and replication dataset.

RESULTS

The motor impulsivity dimension was revealed to be closely connected with individual symptoms of depression and anxiety regardless of whether they were in separate disorder forms or comorbid forms. In all the networks, motor impulsivity was the most important bridge node. The NCT showed comparable network connectivity and network structure between the main and replication datasets.

LIMITATIONS

The use of cross-sectional data limited the inferences about the direction of causality between variables.

CONCLUSIONS

These findings elucidate the psychopathological mechanisms underlying how impulsivity functions within depression, anxiety, and comorbidity and support that motor impulsivity is an important risk factor across different mental disorders and is responsible for comorbidity. The implications of these findings are discussed.

Using Latent Profile Analysis to Characterize Clinical Heterogeneity and Impulsivity in a Large Residential Addiction Treatment Program

Objectives: Clinical heterogeneity among patients in addiction treatment settings represents a challenge as most of the treatment programs are designed to treat substance use disorders (SUD) generally rather than offering more tailored approaches addressing individual patient needs. Systematic characterization of clinical heterogeneity may permit more individualized care paths toward improving outcomes. Methods: Data were collected from a large inpatient SUD treatment program between April 2018 and March 2020 (n = 1519). Latent profile analysis (LPA) was applied to identify latent clusters based on differences in substance use and co-occurring depression, anxiety, and post-traumatic stress disorder. Results: Five distinct profiles emerged: Profile 1 (38%) exhibited the lowest substance use and lowest psychiatric severity (Overall Low); Profile 2 (39%) exhibited high alcohol and psychiatric severity; Profile 3 (13%) exhibited high opioid severity and low psychiatric severity. Profile 4 (8%) exhibited high cannabis use and high psychiatric severity, and profile 5 (3%) exhibited high polysubstance use other than alcohol and cannabis use. The latter two profiles were younger and exhibited higher self-regulatory deficits. The (High Alc/high psych) and the (High Cann/Psych) profiles exhibited differentially higher psychiatric severity. Profiles showing high polysubstance use, as well as high cannabis use and high psychiatric severity, showed significantly higher impulsive behavior than the others. Conclusions: LPA revealed five clusters of patients varying substantially in terms of SUD and psychiatric severity. Addressing common features of clinical heterogeneity for tailored care paths in a personalized treatment approach may improve treatment outcomes.

Impulsivity in fatal suicide behaviour: A systematic review and meta-analysis of psychological autopsy studies

Our aim is to review and perform a meta-analysis on the role of impulsivity in fatal suicide behaviour. We included papers who used psychological autopsy methodology, assessed adult death by suicide, and included assessment of impulsivity. We excluded papers about assisted suicide, terrorist suicide, or other cause of death other than suicide or postmortem diagnosis made only from medical records or database. 97 articles were identified. 33 were included in the systematic review and nine in the meta-analysis. We found that people who die by suicide with high impulsivity are associated with younger age, substance abuse, and low intention to die, whereas those with low impulsivity were associated with older age, depression, schizophrenia, high intention to die and low social support. In the meta-analysis, suicide cases had higher impulsivity scores than living controls (Hedges' g = 0.59, 95 % CI [0.28, 0.89], p=.002). However, studies showed heterogeneity (Q = 90.86, p<.001, I2=89.0 %). Impulsivity-aggressiveness interaction was assessed through meta-regression (β=0.447, p=.045). Individuals with high impulsivity would be exposed to a higher risk of fatal suicide behaviour, aggressiveness would play a mediating role. People who die by suicide with high and low impulsivity display distinct characteristics, which may reflect different endophenotypes leading to suicide by different pathways.

Childhood adversity modulates structural brain changes in borderline personality but not in major depression disorder

Adverse childhood experiences (ACEs) negatively affect the function and structure of emotion brain circuits, increasing the risk of various psychiatric disorders. It is unclear if ACEs show disorder specificity with respect to their effects on brain structure. We aimed to investigate whether the structural brain effects of ACEs differ between patients with major depression (MDD) and borderline personality disorder (BPD). These disorders share many symptoms but likely have different etiologies. To achieve our goal, we obtained structural 3T-MRI images from 20 healthy controls (HC), 19 MDD patients, and 18 BPD patients, and measured cortical thickness and subcortical gray matter volumes. We utilized the Adverse Childhood Experiences (ACE) questionnaire to quantify self-reported exposure to childhood trauma. Our findings suggest that individuals with MDD exhibit a smaller cortical thickness when compared to those with BPD. However, ACEs showed a significantly affected relationship with cortical thickness in BPD but not in MDD. ACEs were found to be associated with thinning in cortical regions involved in emotional behavior in BPD, whereas HC showed an opposite association. Our results suggest a potential mechanism of ACE effects on psychopathology involving changes in brain structure. These findings highlight the importance of early detection and intervention strategies.

Impulsivity across psychiatric disorders in young adults

PURPOSE

Impulsivity is a common cognitive issue across several psychiatric illnesses but is most frequently associated with the DSM-5 Disruptive, Impulse Control and Conduct Disorders, ADHD, and addictive disorders. We hypothesized that a wide range of psychiatric disorders would be associated with elevated impulsivity, not just those commonly linked to impulsiveness. This study aimed to explore the relationship between impulsivity and various psychiatric disorders in young adults.

PROCEDURES

700 non-treatment seeking participants (aged 18-29 years) were enrolled from the general community, provided demographic information, and underwent a psychiatric evaluation to screen for various psychiatric disorders. Each participant then completed the Barratt Impulsiveness Scale (BIS), a self-report measure of impulsivity, followed by the Stop Signal Task (SST), a computerized stop-attention task that measures impulse control. Impulsivity levels across psychiatric disorders were examined by analyzing z-scores relative to controls.

MAIN FINDINGS

Patients with bulimia nervosa, comorbid panic disorder with agoraphobia, and borderline personality disorder showed the highest levels of attentional, motor, and non-planning impulsivity, respectively. The effect size of the difference in total BIS impulsivity was large (d > 0.8) for several conditions including eating, personality, addictive, and mood disorders. The effect size of the difference in impulsivity was not large for any of the measures of ADHD. As compared to other psychiatric disorders analyzed, trichotillomania showed the greatest levels of impulsivity as measured by SST.

PRINCIPAL CONCLUSIONS

This data indicates that a wide range of psychiatric disorders exhibit heightened impulsivity with findings differing across various cognitive domains. Comorbidity resulted in unique findings of elevated impulsivity. This may suggest utility in viewing impulsivity as a transdiagnostic factor for a broad range of psychiatric disorders. Future studies should analyze comorbidities and whether patient psychiatric medication impacts these findings.

An epidemiological survey on personality disorder in Andalusia (the PISMA-ep PD study)

BACKGROUND

Despite a significant clinical and social burden, there is a relative scarcity of epidemiological studies on Personality Disorder (PD).

AIM

To determine the current prevalence of PD and the psychosocial correlates associated with this in the Andalusian population.

METHOD

We carried out a cross-sectional population mental-health survey in Andalusia, southern Spain. Thus, 4,518 randomly selected participants were interviewed following sampling using different standard stratification levels. We used the Spanish version of the SAPAS to estimate PD prevalence. In addition, a full battery of other instruments was utilized to explore global functionality, childhood abuse, maltreatment, threatening life events, personality traits (neuroticism, impulsivity and paranoia), medical and psychiatric comorbidities, family history of psychological problems and other potential risk factors for PD.

RESULTS

PD prevalence (10.8%; 95% CI [9.8, 11.7]) and ran two different multivariate models for PD. We obtained the highest PD prevalence in those affected by any mental disorder plus those reporting having suffered childhood abuse, particularly sexual abuse. Additional potential risk factors or correlates of PD identified were: younger age, lower levels of functioning, less social support, poorer general health, having suffered maltreatment, threatening life events, higher suicidal risk scores and higher levels of both neuroticism and impulsivity.

CONCLUSIONS

This study reports PD prevalence and risk correlates in consonance with similar findings reported in other Western populations. However, longitudinal studies are needed to elicit a more thorough group of prospective determinants of PD.

Differentiating between intrapsychic symptoms and behavioral expressions of borderline personality disorder in relation to childhood emotional maltreatment and emotion dysregulation: an exploratory investigation

BACKGROUND

Borderline personality disorder (BPD) is a severe mental disorder, characterized by pronounced instability in emotions, self-image, and interpersonal relationships. Experiences of childhood maltreatment are among the risk factors for BPD. While self-damaging and aggressive acts often occur, not every person with the disorder shows markedly dysregulated behaviour. Internalized symptoms, such as shame, loneliness, and self-disgust tend to be more pervasive and persist after clinical remission.

OBJECTIVE

Here we investigated associations between BPD symptom severity, childhood maltreatment, and emotion regulation difficulties. We further explored if the Borderline Symptom List (BSL) could potentially be used to differentiate between internalized symptoms (intrapsychic strain) and externalized symptoms (dysregulated behaviours) in future research.

METHOD

187 women with at least mild BPD symptoms (65% having a diagnosis of BPD) completed the BSL 23 including its 11-item supplement (BSL-S), the Childhood Trauma Questionnaire (CTQ), and Difficulties in Emotion Regulation Scale (DERS). Participants further underwent a semi-structured clinical interview to assess BPD criteria (International Personality Disorder Examination, IPDE). Multivariate models and regression-based bootstrapping analyses were performed to test direct and indirect effects.

RESULTS

Childhood trauma severity, especially emotional abuse, positively predicted BPD symptom severity. A significant indirect effect through emotion regulation difficulties was found (k2=.56). When exploring associations with BPD criteria (IPDE), the BSL-23 mean significantly correlated with separation anxiety, identity and mood problems, chronic emptiness, suicidal ideation, and dissociation, while the BSL-S correlated with self-harming impulsive behaviour and anger outbursts.

CONCLUSIONS

Findings complement previous research, highlighting the role of childhood maltreatment and emotion regulation difficulties in BPD. While our findings need to be seen as preliminary and interpreted with caution, they suggest that the BSL may be used to differentiate between internalized symptoms and behavioural expressions of BPD in future research. Such a distinction might help to deepen the understanding of this complex heterogenous disorder.

Gender difference in network relationship between inter-temporal decisions and prefrontal activation levels in internet gaming disorder

Background

Impulsivity and decision-making are key factors in addiction. However, little is known about how gender and time sensitivity affect impulsivity in internet gaming disorder (IGD).

Objective

To investigate the gender difference of impulsive decision-making and relevant brain responses in IGD.

Methods

We conducted a functional magnetic resonance imaging (fMRI) study with 123 participants, including 59 IGD individuals (26 females) and 64 matched recreational game users (RGUs, 23 females). Participants performed a delay-discounting task during fMRI scanning. We examined gender-by-group effects on behavioral and neural measures to explore the preference for immediate over delayed rewards and the associated brain activity. We also investigated the network correlations between addiction severity and behavioral and neural measures, and analyzed the mediating role of brain activity in the link between delay discounting parameters and IGD severity.

Results

We found significant gender-by-group interactions. The imaging results revealed gender-by-group interactions in the dorsolateral prefrontal cortex, medial frontal gyrus, and inferior frontal gyrus (IFG). Post hoc analysis indicated that, for females, RGUs showed higher activity than IGD individuals in these brain regions, while for males IGD individuals exhibited higher activity than RGUs. The activation in the left IFG mediated the relation between Internet Addiction Test score and discount rate in females. In males, the activation in the right dlPFC mediated the relation between IAT score and time sensitivity.

Discussion

Our findings imply that male IGD participants demonstrate impaired intertemporal decisions associated with neural dysfunction. Influencing factors for impulsive decision-making in IGD diverge between males (time sensitivity) and females (discount rate). These findings augment our comprehension of the neural underpinnings of gender differences in IGD and bear significant implications for devising effective intervention strategies for treating people with IGD.

Suicidality in psychiatric emergency department situations during the first and the second wave of COVID-19 pandemic

Psychiatric patients are prone to mental health deterioration during the Covid-19 pandemic. Little is known about suicidality in psychiatric patients during the Covid-19 pandemic. This study is a retrospective chart review of psychiatric emergency department (pED) presentations with present or absent suicidality (5634 pED attendances, 4110 patients) in an academic pED in Berlin, Germany. Poisson regression analysis was performed on the effect of Covid-19 period on suicidality (suicidal ideation (SI), suicide plans (SP) or suicide attempt (SA)) during the first (3/2/2020-5/24/2020 "first-wave") and second (9/15/2020-3/1/2021 "second-wave") wave of the Covid-19 pandemic compared to the same periods one year earlier. During the first-wave the number of pED visits per person with SI, SP and SA was higher compared to one year earlier (SI RR = 1.614; p = 0.016; SP RR = 2.900; p = 0.004; SA RR = 9.862; p = 0.003). SI and SP were predicted by interaction between substance use disorder (SUD) and second-wave (SI RR = 1.305, p = 0.043; SP RR = 1.645, p = 0.018), SA was predicted by interaction between borderline personality disorder (BPD) and second-wave (RR = 7.128; p = 0.012). Suicidality increased during the first-wave of Covid-19 pandemic in our sample. In the second-wave this was found in patients with SUD and BPD. These patients may be at particular risk of suicidality during the Covid-19 pandemic.

The Role of the IL-10 (-819C/T), TNFA (-308G/A) and ENOS (-786T/C) Polymorphisms of Impulsive and Aggressive Personality Traits in Cocaine/Crack Users

Cytokines and nitric oxide have been associated with impulsive and aggressive personality traits. We conducted the first study that investigated the role of SNPs in cytokines and nitric oxide genes and the influence in the progression of aggressive and impulsive behavior in 107 of cocaine and crack users. In this case-control, IL-10 (-819C/T), TNFA (-308G/A) and ENOS (-786T/C) polymorphisms were determined by Real-Time PCR. In addition, the relationship between these polymorphisms and Impulsivity and Aggression was determined. We found that the physical aggressiveness sub score was negatively correlated with the C allele of -819C/T polymorphism of the IL-10 (b = -0.14; p = 0.04). The T allele of the SNP -786T/C of the ENOS gene positively predicts traits of physical aggressiveness (b = 0.14; p = 0.04). The GA genotype (b = 0.22; p = 0.01) and the A allele (b = 0.15; p = 0.02) of -308 G/A polymorphism of the TNFA were positively correlated with aggressiveness physical. The GA genotype (b = 0.20; p = 0.03) was positively correlated with aggressiveness verbal. IL-10 (-819C/T), TNFA (-308G/A) and ENOS (-786T/C) polymorphisms might be associated with high risk of aggressive and impulsive behavior.

The Cognitive, Ecological, and Developmental Origins of Self-Disturbance in Borderline Personality Disorder

Self-disturbance is recognized as a key symptom of Borderline Personality Disorder (BPD). Although it is the source of significant distress and significant costs to society, it is still poorly specified. In addition, current research and models on the etiology of BPD do not provide sufficient evidence or predictions about who is at risk of developing BPD and self-disturbance, and why. The aim of this review is to lay the foundations of a new model inspired by recent developments at the intersection of social cognition, behavioral ecology, and developmental biology. We argue that the sense of agency is an important dimension to consider when characterizing self-disturbances in BPD. Second, we address the poorly characterized relation between self-disturbances and adverse life conditions encountered early in life. We highlight the potential relevance of Life-History Theory-a major framework in evolutionary developmental biology-to make sense of this association. We put forward the idea that the effect of early life adversity on BPD symptomatology depends on the way individuals trade their limited resources between competing biological functions during development.

Control of impulsivity by Gi-protein signalling in layer-5 pyramidal neurons of the anterior cingulate cortex

Pathological impulsivity is a debilitating symptom of multiple psychiatric diseases with few effective treatment options. To identify druggable receptors with anti-impulsive action we developed a systematic target discovery approach combining behavioural chemogenetics and gene expression analysis. Spatially restricted inhibition of three subdivisions of the prefrontal cortex of mice revealed that the anterior cingulate cortex (ACC) regulates premature responding, a form of motor impulsivity. Probing three G-protein cascades with designer receptors, we found that the activation of Gi-signalling in layer-5 pyramidal cells (L5-PCs) of the ACC strongly, reproducibly, and selectively decreased challenge-induced impulsivity. Differential gene expression analysis across murine ACC cell-types and 402 GPCRs revealed that - among Gi-coupled receptor-encoding genes - Grm2 is the most selectively expressed in L5-PCs while alternative targets were scarce. Validating our approach, we confirmed that mGluR2 activation reduced premature responding. These results suggest Gi-coupled receptors in ACC L5-PCs as therapeutic targets for impulse control disorders.

Trait impulsivity in Juvenile Myoclonic Epilepsy

Objective

Impulsivity is a multidimensional construct that can predispose to psychopathology. Meta‐analysis demonstrates an association between response impulsivity and Juvenile Myoclonic Epilepsy (JME), a common genetic generalized epilepsy. Here, we test the hypotheses that trait impulsivity is (i) elevated in JME compared to controls; (ii) moderated by specific seizure characteristics; and (iii) associated with psychiatric adverse effects of antiepileptic drugs (AEDs).

Methods

322 participants with JME and 126 age and gender‐matched controls completed the Barratt’s Impulsiveness Scale (BIS‐brief) alongside information on seizure history and AED use. We compared group BIS‐brief scores and assessed associations of JME BIS‐brief scores with seizure characteristics and AED adverse effects.

Results

The mean BIS‐brief score in JME was 18.1 ± 4.4 compared with 16.2 ± 4.1 in controls (P = 0.0007). Elevated impulsivity was associated with male gender (P = 0.027), frequent absence seizures (P = 0.0004) and lack of morning predominance of myoclonus (P = 0.008). High impulsivity significantly increased the odds of a psychiatric adverse event on levetiracetam (P = 0.036), but not any other psychiatric or somatic adverse effects.

Interpretation

Trait impulsivity is elevated in JME and comparable to scores in personality and neurotic disorders. Increased seizure frequency and absence of circadian seizure pattern moderate BIS score, suggesting disruption of both cortico‐striatal and thalamocortical networks as a shared mechanism between seizures and impulsivity in JME. These findings warrant consideration of impulsivity as a distinct target of intervention, and as a stratifying factor for AED treatment in JME, and perhaps other types of epilepsy. The role of impulsivity in treatment adherence and psychosocial outcome requires further investigation.

Change in core symptoms of borderline personality disorder by tDCS: A pilot study

Borderline personality disorder (BPD) recognizes several psychopathological dimensions related to prefrontal cortex impairments. Transcranial Direct Current Stimulation (tDCS) targeting the right prefrontal dorsolateral cortex (DLPFC) positively influence cognitive functions related to impulsivity in healthy subjects. A randomized double-blind study was designed to investigate whether tDCS could modulate core dimensions (impulsivity, aggression, affective dysregulation) of BPD. Also effects on decision making process and substances craving was assessed. Patients were randomized to receive active-tDCS at 2 mA versus sham-tDCS, once a day for 15 sessions. Anode was placed on the right DLPFC (F4), cathode on the left DLPFC (F3). Impulsivity and aggression measures were significantly reduced only in patients treated with active-tDCS. Decision-making process was marginally influenced by the active current. Craving intensity was reduced only in the active-tDCS sample. Both groups showed improvements in the affective dysregulation dimension and anxious and depressive symptoms. The application of bilateral tDCS targeting right DLPFC with anodal stimulation seems to improve core dimensions of BPD (mainly impulsivity and aggression) probably by restoring prefrontal activity. tDCS might be a potential tool for preventing self-harming behaviors.

Understanding Brain Mechanisms of Reactive Aggression

PURPOSE OF REVIEW

To review the current literature on biobehavioral mechanisms involved in reactive aggression in a transdiagnostic approach.

RECENT FINDINGS

Aggressive reactions are closely related to activations in the brain's threat circuitry. They occur in response to social threat that is experienced as inescapable, which, in turn, facilitates angry approach rather than fearful avoidance. Provocation-induced aggression is strongly associated with anger and deficits in cognitive control including emotion regulation and inhibitory control. Furthermore, the brain's reward system plays a particular role in anger-related, tit-for-tat-like retaliatory aggression in response to frustration. More research is needed to further disentangle specific brain responses to social threat, provocation, and frustration. A better understanding of the psychological and neurobiological mechanisms involved in reactive aggression may pave the way for specific mechanism-based treatments, involving biological or psychotherapeutic approaches or a combination of the two.

Impulsivity in the self-harm and suicidal behavior of young people: A systematic review and meta-analysis

BACKGROUND

Impulsivity is considered a possible phenotype underlying the expression of self-harm and suicidal behaviors. Yet impulsivity is a not a unitary construct and there is evidence that different facets of impulsivity follow different neurodevelopmental trajectories and that some facets may be more strongly associated with such behaviors than others. Moreover, it is unclear whether impulsivity is a useful predictor of self-harm or suicidal behavior in young people, a population already considered to display heightened impulsive behavior.

METHODS

A systematic review and meta-analysis of studies published in Medline, PubMed, PsychInfo or Embase between 1970 and 2017 that used a neurocognitive measure to assess the independent variable of impulsivity and the dependent variable of self-harm and/or suicidal behavior among young people (mean age < 30 years old).

RESULTS

6183 titles were identified, 141 full texts were reviewed, and 18 studies were included, with 902 young people with a self-harm or suicidal behavior and 1591 controls without a history of these behaviors. Deficits in inhibitory control (13 studies, SMD 0.21, p-value = 0.002, 95% confidence interval (CI) (0.08-0.34), prediction interval (PI) = 0.06-0.35) and impulsive decision-making (14 studies, SMD 0.17, p-value = 0.008, 95% CI (0.045-0.3), PI = 0.03-0.31) were associated with self-harm or suicidal behavior. There were no significant differences between measures of different facets of impulsivity (ie. delay discounting, risky decision-making, cognitive or response inhibition) and self-harm or suicidal behavior.

CONCLUSION

Multiple facets of impulsivity are associated with suicidal behavior in young people. Future suicide research should be designed to capture impulsive states and investigate the impact on different subtypes of impulsivity.

Borderline personality disorder

Caretakers are often intimidated or alienated by patients with borderline personality disorder (BPD), compounding the clinical challenges posed by the severe morbidity, high social costs and substantial prevalence of this disorder in many health-care settings. BPD is found in ∼1.7% of the general population but in 15-28% of patients in psychiatric clinics or hospitals and in a large proportion of individuals seeking help for psychological problems in general health facilities. BPD is characterized by extreme sensitivity to perceived interpersonal slights, an unstable sense of self, intense and volatile emotionality and impulsive behaviours that are often self-destructive. Most patients gradually enter symptomatic remission, and their rate of remission can be accelerated by evidence-based psychosocial treatments. Although self-harming behaviours and proneness to crisis can decrease over time, the natural course and otherwise effective treatments of BPD usually leave many patients with persistent and severe social disabilities related to depression or self-harming behaviours. Thus, clinicians need to actively enquire about the central issues of interpersonal relations and unstable identity. Failure to correctly diagnose patients with BPD leads to misleading pharmacological interventions that rarely succeed. Whether the definition of BPD should change is under debate that is linked to not fully knowing the nature of this disorder.