The genetic basis of panic disorder

The Influence of HLA Alleles on the Affective Distress Profile

(1) Background: Affective distress can be triggered by aggressive stimuli with an unfavorable role for the individual. Some of the factors that lead to the development and evolution of a mental disorder can be genetic. The aim of this study is to determine some correlations between the human leukocyte antigen (HLA) genes and the affective distress profile (PDA). (2) Methods: A psychological assessment and testing tool for anxiety was applied to 115 people. The low-resolution HLA alleles of class I (HLA-A, HLA-B, and HLA-C) and class II (HLA-DRB1 and HLA-DQB1) were identified by the PCR technique after DNA extraction from the blood. Depending on the PDA, the subjects were divided into two groups: a group with a low PDA and another one with a medium and high PDA. The IBM SPSS software was used to compare the frequency of HLA alleles between the two groups. (3) Results: The univariate analysis revealed a significant association of the HLA-A locus (A*01, A*30), HLA-B (B*08), and HLA-DRB1 (DRB1*11) with the low PDA group and of the HLA-A locus (A*32), HLA-B (B*52), and HLA-C (C*12) with the medium and high PDA group. (4) Conclusions: The present study highlighted potential associations between HLA alleles and anxiety disorders.

Associations of DNA methylation of HPA axis-related genes and neuroendocrine abnormalities in panic disorder

OBJECTIVE

The purpose of this study was to investigate the role of aberrant DNA methylation of hypothalamic-pituitary-adrenal (HPA) axis-related genes (CRHR1, CRHR2, CRH, FKBP5, HSP90AA1, NR3C1, and POMC) in panic disorder (PD) development. We investigated the correlation among gene methylation levels, adrenocorticotropic hormone (ACTH), cortisol, and PD severity in patients.

METHODS

We compared the methylation levels of HPA axis-related genes between 178 patients with PD and 184 healthy controls using MethylTarget. We then measured ACTH and cortisol levels using chemiluminescence. Disease severity was assessed using the Panic Disorder Severity Scale.

RESULTS

Compared with healthy controls, patients with PD displayed significantly higher levels of ACTH and cortisol, and significantly reduced methylation levels of CRHR1, FKBP5, HSP90AA1, and NR3C1 after correcting for multiple testing using the false discovery method. A significant positive correlation was observed between the methylation of CRHR1, CRHR2, and NR3C1 and ACTH levels in patients with PD, and methylation levels of CRHR1 and NR3C1 were significantly positively related to cortisol levels. In addition, a negative correlation was observed between PD severity and the methylation of CRH, CRHR1, CRHR2, and HSP90AA1.

CONCLUSION

Aberrant methylation of HPA axis-related genes may predict PD development and impact ACTH and cortisol levels.

Co-occurring OCD and Panic Disorder: A Review of Their Etiology and Treatment

Estimated rates of co-occurrence between obsessive and compulsive disorder (OCD) and panic disorder (PD) are notable, but vary considerably, with rates from epidemiological and clinical studies ranging from 1.8% to 22% (Rector et al., 2017). We reviewed the current empirical literature on the etiology, treatment, diagnostic assessment, and differential diagnosis of co-occurring OCD/PD. Best practices for cognitive-behavioral treatment, including identifying and addressing treatment barriers are also addressed. Although it is acknowledged in current literature that co-occurring OCD and PD levels may be clinically significant, there remains a need to thoroughly examine the possible consequences and future research directions of this overlap. Future research must continue to elucidate the biological and environmental causes of OCD/PD co-occurrence.

Heart rate variability changes in patients with panic disorder

BACKGROUND

This review aimed to evaluate whether patients with panic disorder (PD) exhibit different heart rate variability (HRV) compared to healthy controls and to determine whether HRV is different in patients with PD after treatment.

METHODS

Literature databases were searched for studies comparing resting-state HRV between drug-naïve patients with PD and healthy controls. Parameters from the short-term frequency-domain and long-term time domain were included.

RESULTS

In the low frequency (LF) analysis, no significant association was found between LF and PD (standardised mean difference [SMD] = -0.0443, 95% confidence interval [CI]: -0.1765 to 0.0879). In the high frequency (HF) analysis, no significant association was found between HF and PD (SMD = -0.1269, 95% CI: -0.2598 to 0.0059). In the LF/HF analysis, a significantly higher LF/HF ratio was found in cases than in controls, but the effect was moderate (SMD = 0.1390, 95% CI: 0.0180 to 0.2600). For the standard deviation of normal-to-normal intervals, a significantly lower value was observed in cases than in controls (SMD = -0.3133, 95% CI: -0.5459 to -0.0808).

LIMITATIONS

Limited sample size in the time-domain and treatment effect analyses.

CONCLUSIONS

Patients with PD had a higher short-term LF/HF ratio, indicating impaired sympathovagal balance. The LF/HF ratio findings were more consistent compared with LF and HF alone, making it a better parameter to interpret the LF and HF in conjunction. HRV may be a promising biomarker for predicting antidepressant response.

Association between apolipoprotein E genotypes and panic disorder in Turkish population

AIM

In this study, we aimed to investigate possible interactions among the apolipoprotein E (ApoE) and panic disorder (PD), taking into account serum cholesterol levels and subfractions.

METHODS

ApoE genotyping was performed by real-time polymerase chain reaction in DNA samples of PD patient group (n = 45) and healthy control group (n = 50). The serum lipid levels, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) subfraction analysis were examined.

RESULTS

There was a significant difference of ApoE genotypes in patient and control groups. The E3/E3 genotypes lower whereas E4 allele carriers were significantly higher in PD group ApoE4allele carriers had 3.2-fold higher risk of PD. PD group had significantly lower LDL and HDL levels. In spite of the decreased levels of total LDL, antiatherogenic large LDL subgroup was significantly lower in a patient with PD. Antiatherogenic large HDL and Intermediate HDL levels were lower, while atherogenic small HDL subfraction was significantly higher in PD group. Furthermore, Apo E3/E3 genotype carriers had significantly higher large LDL, HDL, large HDL, intermediate HDL level, and also had highest HDL between all the groups. ApoE4 allele carriers while they had highest atherogenic small HDL level.

CONCLUSION

E4 allele can be associated with PD as an eligible risk factor, the E3/E3 could be a risk-reducing factor for PD. Patients with PD not only had lower LDL and HDL levels but also they have higher atherogenic LDL and HDL subfractions. Also, E3/E3 genotype carriers had convenient but ApoE4 carriers had atherogenic plasma cholesterol levels and subfractions.

Oxidative Stress Implications in the Affective Disorders: Main Biomarkers, Animal Models Relevance, Genetic Perspectives, and Antioxidant Approaches

The correlation between the affective disorders and the almost ubiquitous pathological oxidative stress can be described in a multifactorial way, as an important mechanism of central nervous system impairment. Whether the obvious changes which occur in oxidative balance of the affective disorders are a part of the constitutive mechanism or a collateral effect yet remains as an interesting question. However it is now clear that oxidative stress is a component of these disorders, being characterized by different aspects in a disease-dependent manner. Still, there are a lot of controversies regarding the relevance of the oxidative stress status in most of the affective disorders and despite the fact that most of the studies are showing that the affective disorders development can be correlated to increased oxidative levels, there are various studies stating that oxidative stress is not linked with the mood changing tendencies. Thus, in this minireview we decided to describe the way in which oxidative stress is involved in the affective disorders development, by focusing on the main oxidative stress markers that could be used mechanistically and therapeutically in these deficiencies, the genetic perspectives, some antioxidant approaches, and the relevance of some animal models studies in this context.

Polymorphisms in the TMEM132D region are associated with panic disorder in HLA-DRB1*13:02-negative individuals of a Japanese population

We herein report an association between TMEM132D and panic disorder (PD) in a Japanese population, evaluating the effects of HLA-DRB1*13:02, which we previously reported as a susceptibility genetic factor for PD. SNPs in TMEM132D showed significant associations with PD in subjects without HLA-DRB1*13:02 (rs4759997; P=5.02×10⁻⁶, odds ratio=1.50) but not in those with the HLA allele. TMEM132D might have a role in the development of PD in subjects without HLA-DRB1*13:02.

Lifestyle Behaviours Add to the Armoury of Treatment Options for Panic Disorder: An Evidence-Based Reasoning

This article presents an evidence-based reasoning, focusing on evidence of an Occupational Therapy input to lifestyle behaviour influences on panic disorder that also provides potentially broader application across other mental health problems (MHP). The article begins from the premise that we are all different. It then follows through a sequence of questions, examining incrementally how MHPs are experienced and classified. It analyses the impact of individual sensitivity at different levels of analysis, from genetic and epigenetic individuality, through neurotransmitter and body system sensitivity. Examples are given demonstrating the evidence base behind the logical sequence of investigation. The paper considers the evidence of how everyday routine lifestyle behaviour impacts on occupational function at all levels, and how these behaviours link to individual sensitivity to influence the level of exposure required to elicit symptomatic responses. Occupational Therapists can help patients by adequately assessing individual sensitivity, and through promoting understanding and a sense of control over their own symptoms. It concludes that present clinical guidelines should be expanded to incorporate knowledge of individual sensitivities to environmental exposures and lifestyle behaviours at an early stage.

Development and validation of a risk-prediction algorithm for the recurrence of panic disorder

BACKGROUND

To develop and validate a risk prediction algorithm for the recurrence of panic disorder.

METHODS

Three-year longitudinal data were taken from the National Epidemiologic Survey on Alcohol and Related Conditions (2001/2002-2004/2005). One thousand six hundred and eighty one participants with a lifetime panic disorder and who had not had panic attacks for at least 2 months at baseline were included. The development cohort included 949 participants; 732 from different census regions were in the validation cohort. Recurrence of panic disorder over the follow-up period was assessed using the Alcohol Use Disorder and Associated Disabilities Interview Schedule, based on the DSM-IV criteria. Logistic regression was used for deriving the algorithm. Discrimination and calibration were assessed in the development and the validation cohorts.

RESULTS

The developed algorithm consisted of 11 predictors: age, sex, panic disorder in the past 12 months, nicotine dependence, rapid heartbeat/tachycardia, taking medication for panic attacks, feelings of choking and persistent worry about having another panic attack, two personality traits, and childhood trauma. The algorithm had good discriminative power (C statistic = 0.7863, 95% CI: 0.7487, 0.8240). The C statistic was 0.7283 (95% CI: 0.6889, 0.7764) in the external validation data set.

CONCLUSIONS

The developed risk algorithm for predicting the recurrence of panic disorder has good discrimination and excellent calibration. Data related to the predictors can be easily attainable in routine clinical practice. It can be used by clinicians to calculate the probability of recurrence of panic disorder in the next 3 years for individual patients, communicate with patients regarding personal risks, and thus improve personalized treatment approaches.

Immune-related pathways including HLA-DRB1(∗)13:02 are associated with panic disorder

Panic disorder (PD) is an anxiety disorder characterized by panic attacks and anticipatory anxiety. Both genetic and environmental factors are thought to trigger PD onset. Previously, we performed a genome-wide association study (GWAS) for PD and focused on candidate SNPs with the lowest P values. However, there seemed to be a number of polymorphisms which did not reach genome-wide significance threshold due to their low allele frequencies and odds ratios, even though they were truly involved in pathogenesis. Therefore we performed pathway analyses in order to overcome the limitations of conventional single-marker analysis and identify associated SNPs with modest effects. Each pathway analysis indicated that pathways related to immunity showed the strongest association with PD (DAVID, P=2.08×10(-6); i-GSEA4GWAS, P<10(-3); ICSNPathway, P<10(-3)). Based on the results of pathway analyses and the previously performed GWAS for PD, we focused on and investigated HLA-B and HLA-DRB1 as candidate susceptibility genes for PD. We typed HLA-B and HLA-DRB1 in 744 subjects with PD and 1418 control subjects. Patients with PD were significantly more likely to carry HLA-DRB1(∗)13:02 (P=2.50×10(-4), odds ratio=1.54). Our study provided initial evidence that HLA-DRB1(∗)13:02 and genes involved in immune-related pathways are associated with PD. Future studies are necessary to confirm these results and clarify the underlying mechanisms causing PD.

Advances in the neuroimaging of panic disorder

Models of the neuroanatomy of panic disorder (PD) have relied on both animal work on fear and on clinical data from neuroimaging. Early work hypothesised a network of brain regions involved in fear processing (e.g. the amygdala), but more recent work has also pointed to the involvement of other cortical areas and other brain circuitry (e.g. the insula and anterior cingulate cortex). Studies investigating functional and structural brain connectivity in PD may ultimately shed light on the extent to which the neuroanatomy of PD is localised versus distributed, and on how current treatments alter this neuroanatomy.

Anxiety and adverse coronary artery disease outcomes in Chinese patients

OBJECTIVES

To investigate the impact of anxiety on the prognosis of coronary artery disease (CAD) in patients of Chinese Han ethnicity and to explore the correlation between anxiety and the severity of coronary atherosclerosis.

METHODS

Between June 2007 and May 2009, 1007 hospitalized patients with CAD diagnosed by coronary angiography were recruited. The anxiety symptoms were investigated within 2 days after coronary angiography or percutaneous coronary intervention, using the Zung Self-Rating Anxiety Scale. The severity of coronary atherosclerosis was assessed using the modified Gensini score. One and a half years after discharge, the participants were evaluated at the outpatient clinic or by telephone. The primary outcome was the composite of all-cause death and nonfatal myocardial infarction (MI).

RESULTS

A total of 917 (91.1%) patients were evaluated during a mean follow-up period of 17 months. Thirty-five deaths (26 of cardiovascular and 9 of other causes) and 5 nonfatal MIs occurred. The Zung Self-Rating Anxiety Scale score assessed during hospitalization was significantly and independently associated with the Gensini score (β = 1.35, p < .001). Adjusted Cox proportional hazards models showed that anxiety symptoms predicted all-cause death and nonfatal MI (adjusted hazard ratio = 2.43, 95% confidence interval = 1.24-4.75, p = .009).

CONCLUSIONS

Anxiety was independently associated with the severity of coronary atherosclerosis and predicted worse outcome in patients with CAD of Chinese Han ethnicity.

A possible association between panic disorder and a polymorphism in the preproghrelingene

The aim of the study was to investigate whether polymorphisms in the preproghrelin gene are associated with anxiety disorders, such as panic disorder, in humans. Panic disorder is a severe anxiety disorder, characterized by sudden attacks of intense fear or anxiety in combination with somatic symptoms. The preproghrelin gene codes for two gut-derived circulating peptides that have been linked to anxiety-like behaviour in rodents: ghrelin (an orexigenic, pro-obesity hormone) and obestatin. In the present study, we genotyped three missense mutations in the preproghrelin gene in 215 patients suffering from panic disorder and in 451 controls. The A allele of the rs4684677 polymorphism was significantly associated with panic disorder, while there were no significant associations with the two other polymorphisms studied. We conclude that the rs4684677 (Gln90Leu) polymorphism in the preproghrelin gene may be associated with increased risk of panic disorder. It will be important to confirm these findings in additional panic disorder patient groups.

Panic disorder and migraine: comorbidity, mechanisms, and clinical implications

A growing body of literature suggests that comorbid anxiety disorders are more common and more prognostically relevant among migraine sufferers than comorbid depression. Panic disorder (PD) appears to be more strongly associated with migraine than most other anxiety disorders. PD and migraine are both chronic diseases with episodic manifestations, involving significant functional impairment and shared symptoms during attacks, interictal anxiety concerning future attacks, and an absence of identifiable secondary pathology. A meta-analysis of high-quality epidemiologic study data from 1990 to 2012 indicates that the odds of PD are 3.76 times greater among individuals with migraine than those without. This association remains significant even after controlling for demographic variables and comorbid depression. Other less-rigorous community and clinical studies confirm these findings. The highest rates of PD are found among migraine with aura patients and those presenting to specialty clinics. Presence of PD is associated with greater negative impact of migraine, including more frequent attacks, increased disability, and risk for chronification and medication overuse. The mechanisms underlying this common comorbidity are poorly understood, but both pathophysiological (eg, serotonergic dysfunction, hormonal influences, dysregulation of the hypothalamic-pituitary-adrenal axis) and psychological (eg, interoceptive conditioning, fear of pain, anxiety sensitivity, avoidance behavior) factors are implicated. Means of assessing comorbid PD among treatment-seeking migraineurs are reviewed, including verbal screening for core PD symptoms, ruling out medical conditions with panic-like features, and administering validated self-report measures. Finally, evidence-based strategies for both pharmacologic and behavioral management are outlined. The first-line migraine prophylactics are not indicated for PD, and the selective serotonin re-uptake inhibitors used to treat PD are not efficacious for migraine; thus, separate agents are often required to address each condition. Core components of behavioral treatments for PD are reviewed, and their integration into clinical headache practice is discussed.

Bronchiectasis in a diverse US population: effects of ethnicity on etiology and sputum culture

BACKGROUND

Previous studies of patients with bronchiectasis have found that the cause is idiopathic in the majority of cases, but these studies were done in homogeneous populations. We hypothesized that the etiology of bronchiectasis can be determined in a higher percentage of patients in a diverse US population and will differ significantly based on ethnicity.

METHODS

One hundred twelve patients with bronchiectasis confirmed by chest CT scan entered the study. Data from 106 patients were available for full evaluation. Clinical questionnaire, pulmonary function tests, sputum microbiology, laboratory data, and immune function testing were done. Results were analyzed by ethnicity and etiology.

RESULTS

Patients were 61.6% European American (EA), 26.8% African American (AA), 8.9% Hispanic American (HA), and 2.7% Asian American. A cause of bronchiectasis was determined in 93.3% of patients. In 63.2% of patients, bronchiectasis was caused by immune dysregulation, including deficiency (n = 18 [17%]), autoimmune disease (n = 33 [31.1%]), hematologic malignancy (n = 15 [14.2%]), and allergic bronchopulmonary aspergillosis (n = 1 [0.9%]). Rheumatoid arthritis was the cause of bronchiectasis in 28.6% of AA patients vs 6.2% of EA patients (P < .05). Hematologic malignancy was the etiology in 20.0% of the EA patients vs none of the AA patients (P = .02). A significantly higher percentage of HA patients had Pseudomonas aeruginosa in their sputum compared with AA and EA patients (P = .01).

CONCLUSIONS

The etiology of bronchiectasis can be determined in the majority of patients in a heterogeneous US population and is most often due to immune dysregulation. Rheumatoid arthritis is more likely in AA patients than EA patients. HA patients are more likely to have P aeruginosa in their sputum.