Irritability in Mood Disorders: Neurobiological Underpinnings and Implications for Pharmacological Intervention

Irritability in stroke: a protocol for a prospective study

Background

Poststroke irritability (PSI) is common among stroke survivors and can lead to a poor quality of life, difficulties in social interactions, criticism from caregivers, and caregiver stress. The planned study will evaluate the clinical, neuropsychological, and magnetic resonance imaging (MRI) correlates of PSI in a cohort of stroke survivors. In addition, the study will examine the 15-month progression of PSI.

Methods

This will be a prospective cohort study that will recruit 285 participants. Participants and their caregivers will undergo detailed assessments at a research clinic at 3, 9, and 15 months after stroke onset (T1/T2/T3). The irritability/lability subscale of the Chinese version of the Neuropsychiatric Inventory (CNPI) will be completed by caregivers. Potential covariates will also be measured. Patients will undergo MRI, including diffusion-weighted imaging, within 1 week of stroke onset. A stepwise logistic regression will be performed to evaluate the importance of lesions in the regions of interest (ROIs) along with other significant variables identified in univariate analyses. These analyses will be repeated for patients with and without PSI at T2 and T3. Repeated measures analysis of covariance (ANCOVA) will be used to assess changes in CNPI scores for the entire sample. In ANCOVA analyses, the frequency of infarcts in the ROIs will be treated as the predictor.

Discussion

This will be the first MRI study on PSI in stroke survivors. The findings will provide insights into the association of the orbitofrontal cortex, anterior cingulate cortex, anterior temporal lobe, insula, amygdala, thalamus, and basal ganglia lesions with the risk of PSI.

Understanding Irritability From Childhood to Adolescence

We read with great interest the article by Srinivasan et al.,1 and we are heartened to see a renewed focus on irritability as an important phenomenon that necessitates better understanding. In particular, the hypothesis that irritability in childhood may signal the development of psychiatric problems later in life is a persuasive concept that aligns with our thinking.

Study of Rates and Factors Associated to Psychosomatic Syndromes Assessed Using the Diagnostic Criteria for Psychosomatic Research across Different Clinical Settings

INTRODUCTION

Diagnostic Criteria for Psychosomatic Research (DCPR) serve as an instrument for identifying and classifying specific psychosomatic syndromes that are not adequately encompassed in standard nosography. The present study aimed at measuring the prevalence of DCPR syndromes in different clinical settings and exploring factors associated to such diagnoses.

METHODS

A cross-sectional and nationwide study recruited 6,647 patients in different clinical settings: 306 were diagnosed with fibromyalgia (FM), 333 with irritable bowel syndrome, 1,109 with migraine, 2,550 with coronary heart disease (CHD), and 2,349 with type 2 diabetes (T2D). Participants underwent DCPR diagnostic interview and were assessed for depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder 7-Item Scale), and subjective well-being (World Health Organization-5 Well-Being Index). The PsychoSocial Index was used to evaluate global well-being, stress, and abnormal illness behavior. The prevalence of DCPR diagnoses was calculated, and factors associated to such diagnoses were analyzed by logistic regression.

RESULTS

Alexithymia (64.47%), irritable mood (20.55%), and demoralization (15.60%) were the most prevalent psychosomatic syndromes, with demoralization being most common in FM (49.02%). The factors associated to DCPR diagnoses encompassed high anxiety or abnormal illness behavior, and poor well-being. Notably, stress was found to be associated specifically to FM and T2D, with OR of 1.24 (95% CI: 1.06-1.46) and 1.26 (95% CI: 1.18-1.36), respectively.

CONCLUSION

DCPR is a clinically helpful complementary assessment tool in need of being widely implemented in clinical settings in order to have a comprehensive picture of the patients.

Oxytocin treatment rescues irritability-like behavior in Cc2d1a conditional knockout mice

Irritability, a state of excessive reactivity to negative emotional stimuli, is common in individuals with autism spectrum disorder (ASD). Although it has a significant negative impact of patients' disease severity and quality of life, the neural mechanisms underlying irritability in ASD remain largely unclear. We have previously demonstrated that male mice lacking the Coiled-coil and C2 domain containing 1a (Cc2d1a) in forebrain excitatory neurons recapitulate numerous ASD-like behavioral phenotypes, including impaired social behaviors and pronounced repetitive behaviors. Here, using the bottle-brush test (BBT) to trigger and evaluate aggressive and defensive responses, we show that Cc2d1a deletion increases irritability-like behavior in male but not female mice, which is correlated with reduced number of oxytocin (OXT)-expressing neurons in the paraventricular nucleus (PVN) of the hypothalamus. Intranasal OXT administration or chemogenetic activation of OXT neurons in the PVN rescues irritability-like behavior in Cc2d1a conditional knockout (cKO) mice. Administration of a selective melanocortin receptor 4 agonist, RO27-3225, which potentiates endogenous OXT release, also alleviates irritability-like behavior in Cc2d1a cKO mice, an effect blocked by a specific OXT receptor antagonist, L-368,899. We additionally identify a projection connecting the posterior ventral segment of the medial amygdala (MeApv) and ventromedial nucleus of the ventromedial hypothalamus (VMHvl) for governing irritability-like behavior during the BBT. Chemogenetic suppression of the MeApv-VMHvl pathway alleviates irritability-like behavior in Cc2d1a cKO mice. Together, our study uncovers dysregulation of OXT system in irritability-like behavior in Cc2d1a cKO mice during the BBT and provide translatable insights into the development of OXT-based therapeutics for clinical interventions.

An evaluation of the Ultimatum Game as a measure of irritability and anger

The Ultimatum Game is an effective tool for understanding how social decision-making is influenced by emotions in both research and clinical settings. Previous findings have shown that the Ultimatum Game can evoke negative emotions, especially anger and aggression. In a sample of non-clinical adults (N = 143) we evaluated the sensitivity of an anger-infused version of the Ultimatum Game to individual differences in anger and irritability. Findings showed significant relationships between anger and aggressive behaviors in the Ultimatum game, but no association between irritability and aggressive behavior were observed. This indicates that the anger-infused Ultimatum Game is a promising method for studying individual differences in trait anger and anger expression. However, the relationship between decision-making in the anger-infused Ultimatum Game and irritability is less straight forward and needs further investigation. Therefore, when studying the behavioral responses of irritability, it would be beneficial to capture other behaviors beyond aggressive responses.

Efficacy of a synbiotic in the management of adults with Attention-Deficit and Hyperactivity Disorder and/or Borderline Personality Disorder and high levels of irritability: Results from a multicenter, randomized, placebo-controlled, "basket" trial

Irritability worsens prognosis and increases mortality in individuals with Attention-Deficit and Hyperactivity Disorder (ADHD) and/or Borderline Personality Disorder (BPD). However, treatment options are still insufficient. The aim of this randomized, double blind, placebo-controlled study was to investigate the superiority of a synbiotic over placebo in the management of adults with ADHD and/or BPD and high levels of irritability. The study was conducted between February 2019 and October 2020 at three European clinical centers located in Hungary, Spain and Germany. Included were patients aged 18-65 years old diagnosed with ADHD and/or BPD and high levels of irritability (i.e., an Affectivity Reactivity Index (ARI-S) ≥ 5, plus a Clinical Global Impression-Severity Scale (CGI-S) score ≥ 4). Subjects were randomized 1(synbiotic):1(placebo); the agent was administered each day, for 10 consecutive weeks. The primary outcome measure was end-of-treatment response (i.e., a reduction ≥ 30 % in the ARI-S total score compared to baseline, plus a Clinical Global Impression-Improvement (CGI-I) total score of < 3 (very much, or much improved) at week 10). Between-treatment differences in secondary outcomes, as well as safety were also investigated. Of the 231 included participants, 180 (90:90) were randomized and included in the intention-to-treat-analyses. Of these, 117 (65 %) were females, the mean age was 38 years, ADHD was diagnosed in 113 (63 %), BPD in 44 (24 %), both in 23 (13 %). The synbiotic was well tolerated. At week 10, patients allocated to the synbiotic experienced a significantly higher response rate compared to those allocated to placebo (OR: 0.2, 95 % CI:0.1 to 0.7; P = 0.01). These findings suggest that that (add-on) treatment with a synbiotic may be associated with a clinically meaningful improvement in irritability in, at least, a subgroup of adults with ADHD and/or BPD. A superiority of the synbiotic over placebo in the management of emotional dysregulation (-3.6, 95 % CI:-6.8 to -0.3; P = 0.03), emotional symptoms (-0.6, 95 % CI:-1.2 to -0.05; P = 0.03), inattention (-1.8, 95 % CI: -3.2 to -0.4; P = 0.01), functioning (-2.7, 95 % CI: -5.2 to -0.2; P = 0.03) and perceived stress levels (-0.6, 95 % CI: -1.2 to -0.05; P = 0.03) was also suggested. Higher baseline RANK-L protein levels were associated with a significantly lower response rate, but only in the synbiotic group (OR: 0.1, 95 % CI: -4.3 to - 0.3, P = 0.02). In the placebo group, higher IL-17A levels at baseline were significantly associated with a higher improvement in in particular, emotional dysregulation (P = 0.04), opening a door for new (targeted) drug intervention. However, larger prospective studies are warranted to confirm the findings. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03495375.

Irritability across adolescence: Examining longitudinal trajectory, stability, and associations with psychopathology and functioning at age 18

BACKGROUND

Irritability, marked by diminished frustration tolerance, holds significant implications for youth mental health treatment. Despite prior research on irritability trajectories, understanding of individual differences during adolescence remains limited. This study examines the stability and trajectory of irritability across ages 12-18, investigating associations with psychopathology and functioning at age 18.

METHODS

A community sample of families with 3-year-old children (N = 518) was recruited via commercial mailing lists. Irritability was assessed at ages 12, 15, and 18 using the Affective Reactivity Index. Psychopathology at age 18 was evaluated with the Kiddie Schedule for Affective Disorders and Schizophrenia, and functioning was assessed through the UCLA Life Stress Interview. Measurement invariance analyses and latent growth curve modeling were conducted within a structural equation modeling (SEM) framework.

RESULTS

Configural, metric, and scalar invariance models were supported. Elevated irritability at age 12 predicted adverse outcomes at age 18, including increased psychotropic medication use, mental health treatment, suicidal ideation, self-injury, and psychiatric disorders. Importantly, these associations persisted even after accounting for corresponding variables at age 12. The trajectory of irritability during early adolescence significantly predicted heightened risks for various outcomes at age 18, including suicidal ideation, depression, anxiety, disruptive behavior disorders, and impaired interpersonal functioning.

DISCUSSION

Limitations include using only youth-reported data at age 18, limited generalizability from a mostly White, middle-class sample, and insufficient exploration of the broader developmental trajectory of irritability. Nevertheless, the findings emphasize the crucial role of irritability's trajectory in influencing various psychopathological and functional outcomes in late adolescence.

Causal relationship between irritability and asthma: a bidirectional two-sample Mendelian randomization study

INTRODUCTION

Previous studies have suggested a relationship between bad mood and asthma. Therefore, in this study, a two-sample Mendelian randomization (MR) method was used to explore the correlation between irritability and asthma.

MATERIAL AND METHODS

Relevant instrumental variables (IVs) were extracted from the aggregated data of the genome-wide association studies (GWAS) database. Inverse-variance weighting (IVW) and weighted median (WME) were used for the MR analysis to evaluate the causal relationship between irritability and asthma using odds ratios (ORs) and the corresponding 95% confidence intervals (CIs), respectively. The "leave-one-out" method was used for sensitivity analysis.

RESULTS

The results of IVW analysis using random-effects models suggested that irritability increased the risk of asthma (OR = 1.954, 95% CI = 1.188-3.214, p = 0.008). The results of WME were consistent with this observation (OR = 1.934, 95% CI = 1.100-3.400, p = 0.021). Additionally, gastroesophageal reflux disease (GERD) might account for approximately 40% of the relationship between irritability and asthma. The sensitivity analysis revealed the stability of the results.

CONCLUSION

The causal relationship between irritability and asthma was analyzed through MR analysis. Irritability increased the risk of asthma. GERD might play an important mediating role in this relationship.

The pleiotropic contribution of genes in dopaminergic and serotonergic pathways to addiction and related behavioral traits

Introduction

Co-occurrence of substance use disorders (SUD) and other behavioral conditions, such as stress-related, aggressive or risk-taking behaviors, in the same individual has been frequently described. As dopamine (DA) and serotonin (5-HT) have been previously identified as key neurotransmitters for some of these phenotypes, we explored the genetic contribution of these pathways to SUD and these comorbid phenotypes in order to better understand the genetic relationship between them.

Methods

We tested the association of 275 dopaminergic genes and 176 serotonergic genes with these phenotypes by performing gene-based, gene-set and transcriptome-wide association studies in 11 genome-wide association studies (GWAS) datasets on SUD and related behaviors.

Results

At the gene-wide level, 68 DA and 27 5-HT genes were found to be associated with at least one GWAS on SUD or related behavior. Among them, six genes had a pleiotropic effect, being associated with at least three phenotypes: ADH1C, ARNTL, CHRNA3, HPRT1, HTR1B and DRD2. Additionally, we found nominal associations between the DA gene sets and SUD, opioid use disorder, antisocial behavior, irritability and neuroticism, and between the 5-HT-core gene set and neuroticism. Predicted gene expression correlates in brain were also found for 19 DA or 5-HT genes.

Discussion

Our study shows a pleiotropic contribution of dopaminergic and serotonergic genes to addiction and related behaviors such as anxiety, irritability, neuroticism and risk-taking behavior, highlighting a role for DA genes, which could explain, in part, the co-occurrence of these phenotypes.

Irritability: A concept analysis

Irritability is a term used to describe feelings of anger, annoyance and impatience, and is commonly experienced by individuals in daily life. However, there are diverse conceptualizations of irritability in public and clinical research, which often result in confusing irritability with anger and other overlapping concepts. This, in turn, leads to a lack of conceptual clarity. Accordingly, the purpose of this concept analysis was to explore the irritability concept, including its definitions, defining characteristics, antecedents, consequences and empirical referents. The findings showed that irritability is predominantly conceptualized as a psychophysiological concept in the literature. We demonstrated that irritability can be differentiated from overlapping concepts like anger by qualities, such as 'unpredictability and lowered emotion control', 'lowered threshold for negative emotional stimuli', 'being manifested in response to frustrative situations or physiological needs' and 'experience of disproportionate and unjustified emotional irritation'. Importantly, severe irritability prospectively predicts psychiatric disorders and greater impairments in health, financial, educational and social functioning in individuals. Taken together, our analysis showed that one should take into account the context, duration, intensity and importantly outcomes, when assessing irritability in an individual. Considering these findings and the presence of irritability in nursing practice, it is crucial for nurses to recognize and successfully identify this concept in the nursing care they provide within the diverse settings and patient populations.

Irritability and risk of lung cancer: a Mendelian randomization and mediation analysis

BACKGROUND

There is no research to prove the association between irritability and lung cancer, our study performed a Mendelian randomization (MR) approach to elucidate the causal relationship of irritability with lung cancer risk.

METHODS

Genome-wide association studies (GWAS) data of irritability, lung cancer and gastroesophageal reflux disease (GERD) were downloaded from a public database for two-sample MR analysis. Independent single-nucleotide polymorphisms (SNPs) associated with irritability and GERD were selected as instrumental variables (IVs). Inverse variance weighting (IVW) and weighted median method were used to analyze causality.

RESULTS

There is an association between irritability and lung cancer risk (ORIVW = 1.01, 95% CI = [1.00, 1.02], P = 0.018; ORweighted median = 1.01, 95% CI = [1.00, 1.02], P = 0.046), and GERD might account for about 37.5% of the association between irritability and lung cancer.

CONCLUSIONS

This study confirmed the causal effect between irritability and lung cancer through MR analysis, and found that GERD played an essential mediating role in this relationship, which can partly indicate the role of the "inflammation-cancer transformation" process in lung cancer.

The distinction between irritability and anger and their associations with impulsivity and subjective wellbeing

Irritability, anger, and impulsivity have important associations with psychological well-being. However, studying the internal relationships between such emotional constructs is challenging, largely because of the lack of precise operational definitions and extensively validated measurement tools. The aim of this study was to examine relationships between the above emotional constructs and how they relate to satisfaction with life and perceived negative impact on different life domains. Participants (N = 471) completed a self-report questionnaire online. Correlational analyses showed that higher levels of irritability and trait anger were associated with lower life satisfaction. Impulsivity displayed complex relationships with life satisfaction, with some aspects (sensation seeking) showing a positive relationship and others (urgency, lack of perseverance) showing a negative relationship. A two-factor Confirmatory Factor Analysis treating irritability and anger as separate constructs showed a better fit compared with a one-factor model, indicating that irritability and anger should be treated as separate constructs. An exploratory moderation analysis showed that higher irritability predicted increased anger only for participants scoring average to high on urgency (a facet of impulsivity). Our findings increase the understanding of the relationship between these dispositional constructs and supports the conceptualization of irritability and anger as related but distinct constructs.

Network analysis of anxiety and depression in the functionally impaired elderly

Background

Evidence from previous studies has confirmed that functionally impaired elderly individuals are susceptible to comorbid anxiety and depression. Network theory holds that the comorbidity emerges from interactions between anxiety and depression symptoms. This study aimed to investigate the fine-grained relationships among anxiety and depression symptoms in the functionally impaired elderly and identify central and bridge symptoms to provide potential targets for intervention of these two comorbid disorders.

Methods

A total of 325 functionally impaired elderly individuals from five communities in Xi'an, China, were recruited for our investigation. The GAD-7 and PHQ-9 were used to measure anxiety and depression, respectively. SPSS 22.0 software was used for descriptive statistics, and R 4.1.1 software was used for network model construction, expected influence (EI) evaluation and bridge expected influence (BEI) evaluation.

Results

In the network, there were 35 edges (indicating partial correlations between symptoms) across the communities of anxiety and depression, among which the strongest edge was A1 "Nervousness or anxiety"-D2 "Depressed or sad mood." A2 "Uncontrollable worry" and D2 "Depressed or sad mood" had the highest EI values in the network, while A6 "Irritable" and D7 "Concentration difficulties" had the highest BEI values of their respective community. In the flow network, the strongest direct edge of D9 "Thoughts of death" was with D6 "Feeling of worthlessness."

Conclusion

Complex fine-grained relationships exist between anxiety and depression in functionally impaired elderly individuals. "Uncontrollable worry," "depressed or sad mood," "irritable" and "concentration difficulties" are identified as the potential targets for intervention of anxiety and depression. Our study emphasizes the necessity of suicide prevention for functionally impaired elderly individuals, and the symptom "feeling of worthlessness" can be used as an effective target.

A novel exploration of irritability in adolescent males: A preliminary study

OBJECTIVE

Irritability is a key symptom of mood disorders and is common in adolescence; nevertheless, it is poorly understood and assessed. Research examining irritability and its relationship to mood and anxiety disorders risk factors in adolescent males is lacking. Therefore, the current study aimed to address this gap.

METHOD

An online survey designed to interrogate the relationship between irritability and other risk factor variables was administered to 627 adolescent males (ages 12-17). Findings were analysed statistically using MANOVAs.

RESULTS

When divided into high and low irritability groups, higher irritability scores were significantly correlated with higher scores on all risk factor variables. Further, higher irritability scores were associated with higher scores on all variables that indicate an increased risk for development of psychological disorders, such as depression and anxiety.

CONCLUSION

This study is the first to focus on subjective irritability. In adolescent males, it identifies a potentially novel model of irritability's involvement in maladaptive processes relating to emotional dysregulation, behavioural difficulties and anxiety.

Effects of gonadal steroids on reward circuitry function and anhedonia in women with a history of postpartum depression

BACKGROUND

Reward system dysfunction is evident across neuropsychiatric conditions. Here we present data from a double-blinded pharmaco-fMRI study investigating the triggering of anhedonia and reward circuit activity in women.

METHODS

The hormonal states of pregnancy and parturition were simulated in euthymic women with a history of postpartum depression (PPD+; n = 15) and those without such a history (PPD-; n = 15) by inducing hypogonadism, adding back estradiol and progesterone for 8 weeks ("addback"), and then withdrawing both steroids ("withdrawal"). Anhedonia was assessed using the Inventory of Depression and Anxiety Symptoms (IDAS) during each hormone phase. Those who reported a 30 % or greater increase in IDAS anhedonia, dysphoria, or ill temper during addback or withdrawal, compared with pre-treatment, were identified as hormone sensitive (HS+) and all others were identified as non-hormone sensitive (HS-). The monetary incentive delay (MID) task was administered during fMRI sessions at pre-treatment and during hormone withdrawal to assess brain activation during reward anticipation and feedback.

RESULTS

On average, anhedonia increased during addback and withdrawal in PPD+ but not PPD-. During reward feedback, both HS+ (n = 10) and HS- (n = 18) showed decreased activation in clusters in the right putamen (p < .031, FWE-corrected) and left postcentral and supramarginal gyri (p < .014, FWE-corrected) at the withdrawal scans, relative to pre-treatment scans.

LIMITATIONS

A modest sample size, stringent exclusion criteria, and relative lack of diversity in study participants limit the generalizability of results.

CONCLUSION

Although results do not explain differential hormone sensitivity in depression, they demonstrate significant effects of reproductive hormones on reward-related brain function in women.