Do borderline personality disorder and attention-deficit/hyperactivity disorder co-aggregate in families? A population-based study of 2 million Swedes

Physical multimorbidity in psychiatric patients with personality disorders: Insights within the ICD-11 framework

OBJECTIVE

Recent research has revealed poor physical health among individuals with personality disorders (PDs). We aimed to compare chronic physical illnesses (CPI) and chronic physical multimorbidity (CPM) prevalence between the general population (GEP) and PD patients, and to explore the relationship between CPM and various aspects of PD, predominantly within the ICD-11 framework.

METHODS

This cross-sectional study included 126 PD patients and 126 matched controls from the GEP. Patients were evaluated for the ICD-11 PD severity and maladaptive personality domains, subjective emptiness, and reflective functioning. CPI was assessed using a standardized self-report questionnaire.

RESULTS

PD patients had a higher mean number of CPIs (2.05 vs. 1.02) and a more frequent CPM occurrence (49.2% vs. 26.2%) compared to the matched controls (p < .001). The ICD-11 PD severity (OR = 1.143, p = .007) and maladaptive domain Negative affectivity (OR = 4.845, p = .002), and poor reflective functioning (OR = 1.694, p = .007) were significant predictors of CPM, independent of sociodemographic, clinical and lifestyle factors. Negative affectivity showed the most robust effect on CPM, while smoking did not significantly mediate these relationships.

CONCLUSION

Our study found increased CPM burden in PD patients and a link between CPM and various PD aspects under the ICD-11 framework, highlighting the need for more integrated healthcare.

Brexpiprazole Attenuates Aggression, Suicidality and Substance Use in Borderline Personality Disorder: A Case Series

Background: Borderline personality disorder (BPD) is a heterogeneous and highly comorbid disorder. Suicidality, aggression and substance abuse are common presentations of BPD. Our case series is the first to highlight the role of brexpiprazole in improving these symptoms in patients with BPD. Case presentation: We describe three cases demonstrating the role of brexpiprazole in improving BPD's prominent features and comorbidities. All cases improved when brexpiprazole was added to their treatment regime. Case 1: A 26-year-old woman who was diagnosed with BPD and cyclothymia, presented to the psychiatric emergency unit with impulsive suicidal behaviour. Case 2: A 43-year-old woman suffering from BPD sought help due to her violent behaviour and emotional dysregulation. Case 3: A 22-year-old woman with underlying attention deficit and hyperactivity disorder, polysubstance use disorder and BPD presented with dysregulated emotions. Conclusions: Our case series provides anecdotal evidence of the potential role of brexpiprazole in attenuating suicidality, aggression and substance abuse in patients with BPD. We postulate that brexpiprazole's high affinity for the 5HT1A/5HT2A receptors, coupled with its low intrinsic effect on the D2/D3 receptor system, is fundamental in its actions to stabilise the aberrant dopaminergic and serotonergic signalling in BPD. Future research should focus on well-designed clinical trials investigating the efficacy of brexpiprazole in patients with BPD.

Psychometric properties of the Hungarian childhood trauma questionnaire short form and its validity in patients with adult attention-deficit hyperactivity disorder or borderline personality disorder

BACKGROUND

Compelling evidence supports the role of childhood traumatization in the etiology of psychiatric disorders, including adult attention-deficit hyperactivity disorder (aADHD) and borderline personality disorder (BPD). The aim of this study was to examine the psychometric properties of the Hungarian version of the Childhood Trauma Questionnaire Short Form (H-CTQ-SF) and to investigate the differences between patients diagnosed with aADHD and BPD in terms of early traumatization.

METHODS

Altogether 765 (mean age = 32.8 years, 67.7% women) patients and control subjects were enrolled from different areas of Hungary. Principal component analysis and confirmatory factor analysis were carried out to explore the factor structure of H-CTQ-SF and test the validity of the five-factor structure. Discriminative validity was assessed by comparing clinical and non-clinical samples. Subsequently, aADHD and BPD subgroups were compared with healthy controls to test for the role of early trauma in aADHD without comorbid BPD. Convergent validity was explored by measuring correlations with subscales of the Personality Inventory for DSM-5 (PID-5).

RESULTS

The five scales of the H-CTQ-SF demonstrated adequate internal consistency and reliability values. The five-factor model fitted the Hungarian version well after exclusion of one item from the physical neglect scale because of its cross-loading onto the emotional neglect subscale. The H-CTQ-SF effectively differentiated between the clinical and non-clinical samples. The BPD, but not the aADHD group showed significant differences in each CTQ domain compared with the healthy control group. All CTQ domains, except for physical abuse, demonstrated medium to high correlations with PID-5 emotional lability, anxiousness, separation insecurity, withdrawal, intimacy avoidance, anhedonia, depressivity, suspiciousness, and hostility subscales.

CONCLUSIONS

Our study confirmed the psychometric properties of the H-CTQ-SF, an easy-to-administer, non-invasive, ethically sound questionnaire. In aADHD patients without comorbid BPD, low levels of traumatization in every CTQ domain were comparable to those of healthy control individuals. Thus, the increased level of traumatization found in previous studies of aADHD might be associated with the presence of comorbid BPD. Our findings also support the role of emotional neglect, emotional abuse and sexual abuse in the development of BPD.

The p factor of psychopathology and personality in middle childhood: genetic and gestational risk factors

BACKGROUND

A joint, hierarchical structure of psychopathology and personality has been reported in adults but should also be investigated at earlier ages, as psychopathology often develops before adulthood. Here, we investigate the joint factor structure of psychopathology and personality in eight-year-old children, estimate factor heritability and explore external validity through associations with established developmental risk factors.

METHODS

Phenotypic and biometric exploratory factor analyses with bifactor rotation on genetically informative data from the Norwegian Mother, Father, and Child Cohort (MoBa) study. The analytic sub-sample comprised 10 739 children (49% girls). Mothers reported their children's symptoms of depression (Short Moods and Feelings Questionnaire), anxiety (Screen for Anxiety Related Disorders), attention-deficit/hyperactivity disorder inattention and hyperactivity, oppositional-defiant disorder, conduct disorder (Parent/Teacher Rating Scale for Disruptive Behavior Disorders), and Big Five personality (short Hierarchical Personality Inventory for Children). Developmental risk factors (early gestational age and being small for gestational age) were collected from the Medical Birth Registry.

RESULTS

Goodness-of-fit indices favored a p factor model with three residual latent factors interpreted as negative affectivity, positive affectivity, and antagonism, whereas psychometric indices favored a one-factor model. ADE solutions fitted best, and regression analyses indicated a negative association between gestational age and the p factor, for both the one- and four-factor solutions.

CONCLUSION

Correlations between normative and pathological traits in middle childhood mostly reflect one heritable and psychometrically interpretable p factor, although optimal fit to data required less interpretable residual latent factors. The association between the p factor and low gestational age warrants further study of early developmental mechanisms.

Real-life instability in ADHD from young to middle adulthood: a nationwide register-based study of social and occupational problems

BACKGROUND

Studies using self-reports indicate that individuals with ADHD are at increased risk for functional impairments in social and occupational settings, but evidence around real-life instability remains limited. It is furthermore unclear if these functional impairments in ADHD differ across sex and across the adult lifespan.

METHOD

A longitudinal observational cohort design of 3,448,440 individuals was used to study the associations between ADHD and residential moves, relational instability and job shifting using data from Swedish national registers. Data were stratified on sex and age (18-29 years, 30-39 years, and 40-52 years at start of follow up).

RESULTS

31,081 individuals (17,088 males; 13,993 females) in the total cohort had an ADHD-diagnosis. Individuals with ADHD had an increased incidence rate ratio (IRR) of residential moves (IRR 2.35 [95% CI, 2.32-2.37]), relational instability (IRR = 1.07 [95% CI, 1.06-1.08]) and job shifting (IRR = 1.03 [95% CI, 1.02-1.04]). These associations tended to increase with increasing age. The strongest associations were found in the oldest group (40-52 years at start of follow). Women with ADHD in all three age groups had a higher rate of relational instability compared to men with ADHD.

CONCLUSION

Both men and women with a diagnosis of ADHD present with an increased risk of real-life instability in different domains and this behavioral pattern was not limited to young adulthood but also existed well into older adulthood. It is therefore important to have a lifespan perspective on ADHD for individuals, relatives, and the health care sector.

Prevalence of Personality Disorders in Adults With Attention Deficit Hyperactivity Disorder (ADHD)

OBJECTIVE

To estimate the prevalence of PDs according to Millon's evolution-based model among adult ADHD outpatients.

METHOD

Cross-sectional study of consecutive patients referred to an adult ADHD clinic. PDs were evaluated with Millon Clinical Multiaxial Inventory-III (MCMI-III).

RESULTS

One-hundred-eighty-one participants had valid MCMI-III, of whom147 were diagnosed with ADHD. Mean age: 32.97, SD:11.56, females: 74 (50.3%). Among the 147 participants with ADHD, 29 (19.7%) did not meet criteria for any PD, 43 (29.3%) met the criteria for one PD, 34 (23.1%) for two PDs and the rest three or more. Most common PD was Dependent (n = 58) followed by Depressive (n = 45). Inattentive sub-type was associated with dependent PD, while combined type with antisocial, negativistic (passive/aggressive) and sadistic PD.

CONCLUSION

Particular personality profiles were more common with different ADHD subtypes. Given the developmental origins of PD, further research may help identify possible links with childhood difficulties.

Comparing Differences between Two Groups of Adolescents Hospitalized for Self-Harming Behaviors with and without Personality Disorders

Self-harm (non-suicidal self-injury (NSSI) and suicidal behavior (SB)) is frequent display during adolescence. Patients with personality disorders (PDs) frequently self-harm. However, few studies have focused on the role of PDs in self-harming adolescents. In this study, we collected 79 adolescents hospitalized due to self-harm (88.6% female; 78.5% Caucasian) and divided them into two groups, with or without a diagnosis of PD. The socio-demographic and psychological-clinical data were collected through a structured interview by clinicians. Univariate, subgroup, and multiple logistic regression analyses were performed. Univariate analysis showed that adolescents with a PD and self-harm had (1) an older age at hospitalization (p < 0.01); (2) experienced physical and sexual abuse (p = 0.05, and p < 0.01, respectively); (3) ADHD (p = 0.05); (4) a greater number of SA (p < 0.01); and (5) probability of being a major NSSI patient (>20 lifetime NSSI episodes) (p < 0.01). After multivariate stratified analysis, the results indicated that an older age, and particularly major NSSI status were predictors of PD diagnosis. Early identification and a better understanding of the characteristics of adolescent PDs can assist clinicians in intervening earlier and developing more rational treatment strategies to reduce the long-term effects of PDs.

Risk and resilience factors impacting the mental health and wellbeing of siblings of individuals with neurodevelopmental conditions: A mixed methods systematic review

OBJECTIVE

This pre-registered systematic review synthesised and evaluated the existing literature on self-reported mental health and wellbeing of siblings of individuals with neurodevelopmental conditions (NDCs).

METHODS

From 2437 identified studies published 2000-2022, 81 studies were included: 14 population- or cohort-based, 39 quantitative, 7 mixed method, and 21 qualitative outcome studies.

RESULTS

Seven sibling mental health (any psychiatric disorder, anxiety, depression, bipolar disorder, schizophrenia, internalising and externalising difficulties) and five wellbeing indicators were identified (quality of life, emotional adjustment, social wellbeing, somatic/physical wellbeing, and resilience/growth). Overall, siblings had increased risk of any psychiatric disorder, but they also reported experiences of growth and resilience, primarily in qualitative studies. 41 risk factors and 24 resilience factors associated with these outcomes were identified; the most frequently cited risk factor was symptom severity of the NDC sibling, while the most common resilience factor was adaptive/active coping at the individual sibling level. Studies showed high methodological heterogeneity and 90 different self-report measures were used.

CONCLUSIONS

Sibling mental health indictors are heterogeneous and cumulative risk factors may result in poorer wellbeing. There is a need for consistent reporting of family and sibling characteristics, a strengths-based approach to assessment, and identification of protective and resilience-promoting factors.

Childhood symptoms of attention-deficit/hyperactivity disorder and borderline personality disorder

OBJECTIVE

Childhood attention-deficit /hyperactivity disorder (ADHD) is known to be associated with adult Borderline Personality Disorder (BPD). We investigated if any of the subdimensions of childhood ADHD, that is, impulsivity, inattention, or hyperactivity was more prominent in this association.

METHODS

In a nation-wide cohort (N = 13,330), we utilized parent reported symptoms of childhood ADHD and clinically ascertained adult BPD diagnoses. The summed total scores of ADHD symptoms and its three subdimensions were used and standardized for effect size comparison. Associations were analyzed using Cox regression with sex and birth-year adjustments. Secondary outcomes were BPD-associated traits (i.e., self-harm and substance use) analyzed using logistic- and linear regression respectively.

RESULTS

ADHD symptom severity was positively associated with BPD with a hazard ratio (HR) of 1.47 (95% confidence interval [CI]: 1.22-1.79) per standard deviation increase in total ADHD symptoms. Impulsivity was the most prominent subdimension with the only statistically significant association when analyzed in a model mutually adjusted for all ADHD subdimensions-HR for inattention: 1.15 (95% CI: 0.85-1.55), hyperactivity: 0.94 (95% CI: 0.69-1.26), impulsivity: 1.46 (95% CI: 1.12-1.91). In secondary analyses, weak positive associations were seen between total ADHD symptom score and self-harm and substance use. In analyses by subdimensions of ADHD, associations were weak and most prominent for inattention in the model with self-harm.

CONCLUSION

Childhood ADHD symptoms were associated with subsequent development of BPD diagnosis and appeared to be driven primarily by impulsivity. Our findings are important for understanding the association between childhood symptoms of ADHD and subsequent BPD.

Efficacy of Online Intervention for ADHD: A Meta-Analysis and Systematic Review

Background

With the popularity of computers, the internet, and the global spread of COVID-19, more and more attention deficit hyperactivity disorder (ADHD) patients need timely interventions through the internet. At present, there are many online intervention schemes may help these patients. It is necessary to integrate data to analyze their effectiveness.

Objectives

Our purpose is to integrate the ADHD online interventions trials, study its treatment effect and analyze its feasibility, and provide reference information for doctors in other institutions to formulate better treatment plans.

Methods

We searched PubMed, EMBASE and Cochrane libraries. We didn't limit the start date and end date of search results. Our last search was on December 1, 2021. The keyword is ADHD online therapy. We used the Cochrane bias risk tool to assess the quality of included studies, used the standardized mean difference (SMD) as an effect scale indicator to measure data. Random effects model, subgroup analysis were used to analyze the data.

Results

Six randomized controlled trials (RCTs) were identified, including 261 patients with ADHD. These studies showed that online interventions was more effective than waiting list in improving attention deficit and social function of adults and children with ADHD. The attention deficit scores of subjects were calculated in six studies. The sample size of the test group was 123, the sample size of the control group was 133, and the combined SMD was −0.73 (95% confidence interval: −1.01, −0.44). The social function scores of subjects were calculated in six studies. The sample size of the experimental group was 123 and the control group was 133. The combined SMD was −0.59 (95% confidence interval: −0.85, −0.33).

Conclusions

The results show that online interventions of ADHD may be an effective intervention. In the future, we need more online intervention researches to improve the symptoms of different patients, especially for some patients who have difficulties in accepting face-to-face treatment.

Borderline personality disorder (BPD) and attention deficit hyperactivity disorder (ADHD) revisited - a review-update on common grounds and subtle distinctions

BACKGROUND

Overlap in symptom domains particularly in the field of impulsivity and emotional dysregulation in attention deficit hyperactivity disorder (ADHD) and borderline personality disorder (BPD) have stimulated further research activities since our last review from 2014.

MAIN BODY

Disentangling features of impulsivity in ADHD and BPD revealed that impulsivity is a feature of both disorders with patients suffering from both ADHD and BPD having highest impulsivity ratings. BPD individuals have more problems using context cues for inhibiting responses and their impulsivity is stress-dependent, whereas ADHD patients have more motor impulsivity and therefore difficulties interrupting ongoing responses. For emotion regulation difficulties the ranking order ranges from ADHD to BPD to the comorbid condition, again with the patients suffering from both, ADHD and BPD, having the most pronounced emotion regulation problems. Environmental influences namely adverse childhood events were shown to be linked to both ADHD and BPD. Traumatic experiences seem independently linked to impulsivity features. Thus, some authors point to the risk of misdiagnosis during childhood and the necessity to screen for traumatic experiences in both patient groups. Genetic research confirmed genetic overlap of BPD with bipolar disorder (BD) and schizophrenic disorders, as well as genetic overlap of BD and ADHD. A population-based study confirmed the high co-occurrence and familial co-aggregation of ADHD and BPD. Interesting questions in the field of gene-environment-interactions are currently dealt with by genetic and epigenetic research. Few studies have investigated treatment strategies for the comorbid condition, though the issue is highly important for the management of patients suffering from both disorders and presenting with the highest symptom scores.

CONCLUSION

Research on the different impulsivity features might point to a necessity of disorder-specific treatment strategies in the field of impulse control. Future research is needed to base treatment decisions for the comorbid condition on an evidence basis.

Familial risk and heritability of diagnosed borderline personality disorder: a register study of the Swedish population

Family and twin studies of Borderline Personality Disorder (BPD) have found familial aggregation and genetic propensity for BPD, but estimates vary widely. Large-scale family studies of clinically diagnosed BPD are lacking. Therefore, we performed a total-population study estimating the familial aggregation and heritability of clinically diagnosed BPD. We followed 1,851,755 individuals born 1973-1993 in linked Swedish national registries. BPD-diagnosis was ascertained between 1997 and 2013, 11,665 received a BPD-diagnosis. We identified relatives and estimated sex and birth year adjusted hazard ratios, i.e., the rate of BPD-diagnoses in relatives to individuals with BPD-diagnosis compared to individuals with unaffected relatives, and used structural equation modeling to estimate heritability. The familial association decreased along with genetic relatedness. The hazard ratio was 11.5 (95% confidence interval (CI) = 1.6-83.8) for monozygotic twins; 7.4 (95% CI = 1.0-55.3) for dizygotic twins; 4.7 (95% CI = 3.9-5.6) for full siblings; 2.1 (95% CI = 1.5-3.0) for maternal half-siblings; 1.3 (95% CI = 0.9-2.1) for paternal half-siblings; 1.7 (95% CI = 1.4-2.0) for cousins whose parents were full siblings; 1.1 (95% CI = 0.7-1.8) for cousins whose parents were maternal half-siblings; and 1.9 (95% CI = 1.2-2.9) for cousins whose parents were paternal half-siblings. Heritability was estimated at 46% (95% CI = 39-53), and the remaining variance was explained by individually unique environmental factors. Our findings pave the way for further research into specific genetic variants, unique environmental factors implicated, and their interplay in risk for BPD.

Heterogeneity in brain functional changes of cognitive processing in ADHD across age: A systematic review of task-based fMRI studies

This review aims to establish the cognitive processing of patients with attention-deficit hyperactive disorder (ADHD) across age. Functional magnetic resonance imaging (fMRI) studies on children and adult populations were conducted, thus delineating deficits that could have been maintained and ameliorated across age. This allowed for the examination of the correlation between patterns of brain activation and the corresponding development of functional heterogeneity in ADHD. A systematic literature search of fMRI studies on ADHD was conducted using the PubMed and Scopus electronic databases based on PRISMA guidelines. References and citations were verified in Scopus database. The present study has identified 14 studies on children, 16 studies on adults, and one study on both populations of ADHD consisting of 1371 participants. Functional heterogeneity is present in ADHD across age, which can manifest either as different brain activation patterns, intra-subject variability, or both. This is shown in the increased role of the frontal regions and the specialized network in adults with ADHD from inefficient non-specific activation in childhood. Functional heterogeneity may manifest when delayed maturation is insufficient to normalize frontal lobe functions.

Validity of the personality disorder diagnosis in the Swedish National Patient Register

AIMS

The Swedish National Patient Register (NPR) is an exceptional source of information in clinical epidemiological research. The register is, however, not validated for the diagnosis of personality disorder (PD). We therefore assessed its validity in this patient group, and the group with emotionally unstable PD (EUPD)/borderline personality disorder (BPD).

METHODS

Records from 100 random adult patients (aged 15-65 years) diagnosed with any PD in the NPR between 1987 and 2015 were analysed using a protocol based on general diagnostic criteria for PD, as well as specific criteria for EUPD/BPD in both ICD and DSM classification systems.

RESULTS

Of the 100 patients, 27 had been given a diagnosis of EUPD, 23 another specific PD and 50 an unspecified PD. Using ICD criteria, 88 of 95 evaluable patients could be confirmed to have a PD, that is an agreement rate of 93%. Using DSM criteria, the agreement was lower (77 patients or 81%). Of 26 evaluable patients with a diagnosis of EUPD/BPD, the diagnosis was confirmed in all cases when using the ICD criteria, but in only 20 when using the DSM criteria.

CONCLUSIONS

The NPR is a valid source of data for the diagnosis of PD per se and also of EUPD in women.

Physical exercise in attention deficit hyperactivity disorder - evidence and implications for the treatment of borderline personality disorder

A growing body of literature indicates a potential role for physical exercise in the treatment of attention deficit hyperactivity disorder (ADHD). Suggested effects include the reduction of ADHD core symptoms as well as improvements in executive functions. In the current review, we provide a short overview on the neurophysiological mechanisms assumed to underlie the beneficial effects of exercise. Further, we review the current evidence from experimental studies regarding both acute exercise and long-term interventions in ADHD. While the positive effects observed after acute aerobic exercise are promising, very few well-designed long-term intervention studies have been conducted yet. Moreover, although exercise effects have not yet been studied in borderline personality disorder (BPD), in the end of this paper we derive hypotheses why exercise could also be beneficial for this patient population.

Borderline personality disorder and attention deficit/hyperactivity disorder in adolescence: overlap and differences in a clinical setting

BACKGROUND

With increased consensus regarding the validity and reliability of diagnosing Borderline Personality Disorder (BPD) in adolescents, clinicians express concern over the distinction between BPD and Attention-Deficit/Hyperactivity Disorder (ADHD), and its co-morbidity in clinical settings. The goal of this study was to evaluate differences between BPD, ADHD and BPD + ADHD in terms of co-morbid psychiatric disorders and a range of self-reported behavioral problems in adolescents.

METHODS

Our sample consisted of N = 550 inpatient adolescents with behavioral and emotional disorders that have not responded to prior intervention. We took a person-centered approach (for increase clinical relevance) and compared adolescents with ADHD, BPD and ADHD+BPD in terms of co-occurring psychiatric disorders and behavioral problems. We performed a regression analysis to test whether BPD symptoms make an incremental contribution to the prediction of psychiatric symptoms over ADHD symptoms.

RESULTS

The severity of almost all co-occurring disorders, aggression, self-harm, suicidal thoughts, and substance use, were higher in the ADHD+BPD group. Borderline symptoms made an incremental contribution to the prediction of psychiatric symptoms beyond the contribution of ADHD.

CONCLUSION

Severity and co-morbidity may be helpful factors in distinguishing between ADHD and BPD in clinical practice and the co-morbidity of these two disorders may indicate a worse clinical outcome.

The role of environmental influences in the complex relationship between borderline personality disorder and attention-deficit/hyperactivity disorder: review of recent findings

BACKGROUND

In recent years, the existence of possible developmental pathways from childhood Attention-Deficit/Hyperactivity Disorder (ADHD) to adult Borderline Personality Disorder (BPD) has been suggested. The existence of common genetic factors has been described but there is little evidence on the role of environmental factors in the possible transition from one disorder to another throughout life. The main goal of this work is to review the literature about the existing evidence on childhood traumas as factors that mediate the risk of developing BPD in children with ADHD.

METHODS

A literature search was conducted using PubMed, Science Direct and PsychInfo databases. Criteria included studies of BPD and ADHD relationships and childhood traumas as environmental influences from epidemiological or clinical samples.

RESULTS

The review only identified 4 studies that matched the search criteria. All studies retrospectively analyzed childhood traumas, and adult patients with BPD, with or without comorbid ADHD, were the most frequently mentioned. The analyzed evidence reinforces the relationship between the number of childhood traumas and higher clinical severity. Three of these analyzed studies describe an increased the risk of children with ADHD who report emotional and sexual traumatic experiences to develop BPD in adulthood.

CONCLUSIONS

The experience of traumatic childhood events, especially those of an emotional type, may have a mediating effect of an increased risk of developing adult BPD in childhood ADHD patients. However, to consider them as risk factors, more studies, and especially longitudinal studies, are necessary to clarify the probable transactional process between the two disorders. Evidence from these studies may be helpful to develop early intervention programs to reduce the functional impairment associated with the two disorders.

A Potential Role for the STXBP5-AS1 Gene in Adult ADHD Symptoms

We aimed to detect Attention-deficit/hyperactivity (ADHD) risk-conferring genes in adults. In children, ADHD is characterized by age-inappropriate levels of inattention and/or hyperactivity-impulsivity and may persists into adulthood. Childhood and adulthood ADHD are heritable, and are thought to represent the clinical extreme of a continuous distribution of ADHD symptoms in the general population. We aimed to leverage the power of studies of quantitative ADHD symptoms in adults who were genotyped. Within the SAGA (Study of ADHD trait genetics in adults) consortium, we estimated the single nucleotide polymorphism (SNP)-based heritability of quantitative self-reported ADHD symptoms and carried out a genome-wide association meta-analysis in nine adult population-based and case-only cohorts of adults. A total of n = 14,689 individuals were included. In two of the SAGA cohorts we found a significant SNP-based heritability for self-rated ADHD symptom scores of respectively 15% (n = 3656) and 30% (n = 1841). The top hit of the genome-wide meta-analysis (SNP rs12661753; p-value = 3.02 × 10^-7) was present in the long non-coding RNA gene STXBP5-AS1. This association was also observed in a meta-analysis of childhood ADHD symptom scores in eight population-based pediatric cohorts from the Early Genetics and Lifecourse Epidemiology (EAGLE) ADHD consortium (n = 14,776). Genome-wide meta-analysis of the SAGA and EAGLE data (n = 29,465) increased the strength of the association with the SNP rs12661753. In human HEK293 cells, expression of STXBP5-AS1 enhanced the expression of a reporter construct of STXBP5, a gene known to be involved in "SNAP" (Soluble NSF attachment protein) Receptor" (SNARE) complex formation. In mouse strains featuring different levels of impulsivity, transcript levels in the prefrontal cortex of the mouse ortholog Gm28905 strongly correlated negatively with motor impulsivity as measured in the five choice serial reaction time task (r² = - 0.61; p = 0.004). Our results are consistent with an effect of the STXBP5-AS1 gene on ADHD symptom scores distribution and point to a possible biological mechanism, other than antisense RNA inhibition, involved in ADHD-related impulsivity levels.

Attention Deficit Hyperactivity Disorder And Borderline Personality Disorder In Adults: A Review Of Their Links And Risks

Attention deficit hyperactivity disorder (ADHD) and borderline personality disorder (BPD) are particularly common disorders, that are highly comorbid in adult populations. The symptomatic overlap between adult ADHD and BPD includes impulsivity, emotional dysregulation and interpersonal impairment, which makes the differential diagnosis difficult. Our review aims at focusing on recent data on the comorbid ADHD+BPD form, as well as the risk factors involved in the emergence of the two disorders. While adult ADHD and BPD share some genetic and temperamental risk factors, adult ADHD is characterized by more severe trait-impulsivity compared to non-comorbid BPD; BPD patients display more severe trait-emotion regulation symptoms compared to non-comorbid ADHD. Patients with the comorbid ADHD+BPD form have severe symptoms in both dimensions. Early-life exposure to adverse events is a shared risk factor for the development of ADHD and BPD, but type and timing of adversity seem to play a differential role in the development of BPD and ADHD symptoms. Age of onset used to be a discriminative diagnostic criterion between ADHD, an early-onset neurodevelopmental disorder, and BPD, a late-onset psychological disorder. However, this distinction has been recently called into question, increasing the need for more research aiming at delineating the disorders from a developmental and clinical standpoint. Clinicians should carefully consider the comorbidity, and consider ADHD and BPD dimensionally, in order to provide more effective patient management. This might improve early preventive interventions, and treatment for comorbid conditions in adulthood.