Association between the Catechol-O-Methyltransferase (COMT) Val¹⁵⁸Met Polymorphism and Alexithymia in Patients with Obsessive-Compulsive Disorder

[Alexithymia in Multiple Sclerosis - Narrative Review]

Alexithymia is a multidimensional construct of personality implicating difficulties in identifying and describing another's feelings, and externally oriented thinking. It is broadly reported in psychiatric patients but has gained little attention regarding its occurrence and pathophysiology in multiple sclerosis (MS). This narrative review aims to address prevalence, etiology, neurobiological, and clinical findings of alexithymia. The prevalence of alexithymia in MS ranges from 10 to 53%. There seems to be an association with anxiety, depression, fatigue, and some aspects of social cognition, while the relationship with clinical and classical cognitive variables was rarely evaluated. Only a few studies referred to its pathophysiology assuming an aberrant interhemispheric transfer or regional cerebral abnormalities. The prevalence of alexithymia in MS and the potential negative impact on quality of life and interpersonal communication could severely impact clinical MS management and a screnning for these factors should be mandatory. Thus, further evaluation is needed concerning its relationship with clinical, emotional, and cognitive confounders. Large-scale studies employing neuroimaging techniques are needed for a better understanding of the neural underpinnings of this MS feature.

Relationship between gene-environment interaction and obsessive-compulsive disorder: A systematic review

BACKGROUND

Gene-environment interaction (G × E) refers to the change of genetic effects under the participation of environmental factors resulting in differences in genetic expression. G × E has been studied in the occurrence and development of many neuropsychiatric disorders, including obsessive-compulsive disorder (OCD).

AIM

A systematic review was conducted to investigate the role of G × E plays in OCD. This review explored the relationship between G × E and the susceptibility to OCD occurrence, disease progression, and treatment response.

METHODS

This systematic literature search was performed using Web of Science, PubMed, Cochrane Library, and CNKI. Seven studies were selected, which included seven genes (BDNF, COMT, MAO, 5-HTT, SMAD4, PGRN, and SLC1A1) polymorphisms, polygenic risk score (PRS), and two environmental factors (childhood trauma and stressful life events).

RESULTS

Information from this systematic review indicated that G × E increased the susceptibility to OCD, played a crucial role in the clinical characteristics, and had an inconsistent impact on treatment response of OCD.

FUTURE DIRECTIONS

The multi-omics studies and the inclusion of G × E in future GWAS studies of OCD should be drawn more attention, which may contribute to a deeper understanding of the etiology of OCD as well as guide therapeutic interventions for the disease.

Emotional dysregulation, alexithymia and neuroticism: a systematic review on the genetic basis of a subset of psychological traits

Neuroticism, alexithymia and emotion dysregulation are key traits and known risk factors for several psychiatric conditions. In this systematic review, the aim is to evaluate the genetic contribution to these psychological phenotypes. A systematic review of articles found in PubMed was conducted. Search terms included 'genetic', 'GWAS', 'neuroticism', 'alexithymia' and 'emotion dysregulation'. Risk of bias was assessed utilizing the STREGA checklist. Two hundred two papers were selected from existing literature based on the inclusion and exclusion criteria. Among these, 27 were genome-wide studies and 175 were genetic association studies. Single gene association studies focused on selected groups of genes, mostly involved in neurotransmission, with conflicting results. GWAS studies on neuroticism, on the other hand, found several relevant and replicated intergenic and intronic loci affecting the expression and regulation of crucial and well-known genes (such as DRD2 and CRHR1). Mutations in genes coding for trascriptional factors were also found to be associated with neuroticism (DCC, XKR6, TCF4, RBFOX1), as well as a noncoding regulatory RNA (LINC00461). On the other hand, little GWAS data are available on alexythima and emotional dysregulation.

[Psychosocial pathomorphosis of depressions]

OBJECTIVE

The aim is to determine the changes in phenomenology of depressions (mostly of melancholic type with pronounced affect of sadness, chronobiological shift, neurovegetative changes and typical affect-congruent depressive ideas) over the past decades.

MATERIAL AND METHODS

We've compared the archival data of one of the authors (V.N.K.) obtained in the study of depression within 1980-1086 years (1st group, 103 patients, 47 with recurrent depression and 56 with bipolar depression) and the data of the study of depression during 2015-2021 years with registration of symptoms with the same psychopathological scale at the same clinic for affective disorders (2nd group, 109 patients, 52 with recurrent depression and 57 with bipolar depression). The groups are age-comparable (21-59 y.o.). The Hamilton Depression Rating Scale (HDRS-17) has been used to assess the severity of depression (score of 21-32 in both groups). Statistics included frequency analysis with use of χ2 criterion.

RESULTS

Biologically mediated symptoms (shortened sleep with early awakening, typical diurnal variations with vitalization of depressive affect and loss of energy mostly first half of day, decreased appetite, libido and motivation for any activity) were not statistically different in the study groups. Whereas symptoms associated with emotional reactivity and congruent depressive ideations like worthlessness, guilt, suicidal thoughts, as well as anaesthesia psychica dolorosa - were statistically rare in 2nd group, except anhedonia. The same time the facts which have been obvious amongst patients of 2nd group were the difficulties to verbalize their feelings, shortage of vocabular for reflections about their suffering, especially amongst young patients.

CONCLUSION

The results of the study can indicate some changes in the phenomenology of depression over the past decades. Basically, the same underlying disorders can produce different clinical presentation, particularly concerning an awareness and verbalization of moral feelings and other emotions. One of the possible psycholinguistic assumption may be limited vocabulary for feelings because of spreading social networks with very poor and formal language instead of live direct communication.

Plasma circulating micro-RNAs associated with alexithymia reflect a high overlap on neuropsychiatric outcomes

BACKGROUND

Alexithymia ("no word for feelings") is a personality feature that is common in patients with psychiatric disorders. However, little is known about biological causes and mechanism behind. Research so far focusses on genetic risk variants primary associated with depression, but analyses on epigenetic mechanisms are still missing.

METHODS

In a sample of n = 813 subjects from the "Study of Health in Pomerania" we analyzed the association between alexithymia and plasma circulating micro RNAs (miRNA). Significant miRNAs were compared to associations regarding depression and pathway analyses were performed.

RESULTS

Two miRNAs were significantly associated with at least one of the alexithymia scores (hsa-miR-324-3p, hsa-miR-33a-5p) and three miRNAs additionally revealed a strong association pattern to alexithymia (hsa-miR-106b-5p, hsa-miR-484, hsa-miR-25-3p). None of these miRNAs was significantly associated with depressive symptoms in our sample. Literature research showed that all of the miRNAs have been found in association with several neuropsychiatric phenotypes.

LIMITATIONS

Main limitations are the lack of a replication sample as well as the limited number of miRNAs analyzed.

CONCLUSIONS

This is the first analysis investigating the association between miRNAs and alexithymia. Results indicate that miRNAs are not specific for one psychiatric disorder but may influence biological mechanisms that are involved in various psychiatric conditions which might be relevant for future treatment options and improve the biological understanding of psychiatric conditions.

Influence of Catechol-O-Methyltransferase Gene Polymorphism on the Correlation between Alexithymia and Hypervigilance to Pain

The psychological characteristic of having difficulty expressing emotions, known as alexithymia, is associated with hypervigilance to pain and is considered one of the risk factors for chronic pain. The correlation between alexithymia and hypervigilance to pain can be observed even in healthy individuals. However, the factors influencing this correlation remain unknown. We explored the dopamine system, which is known to be involved in emotion and pain. The dopamine-degrading enzyme catechol-O-methyltransferase (COMT) has a genetic polymorphism known to influence dopamine metabolism in the prefrontal cortex. COMT polymorphism reportedly affects various aspects of pain and increases pain sensitivity in Met allele carriers. Therefore, we investigated whether the correlation between alexithymia and hypervigilance to pain is influenced by COMT polymorphism in healthy individuals. The results revealed a significant positive correlation between the "difficulty describing feelings" of the 20-item Toronto Alexithymia Scale and the "attention to changes in pain" of the pain vigilance and awareness questionnaire in COMT Met carriers but not in Val/Val individuals. This finding suggests that the correlation between alexithymia and hypervigilance to pain is influenced by COMT polymorphism.

Evaluation of alexithymia in individuals with chronic pain in a Mexican population: Alexithymia in a Mexican population

INTRODUCTION

Alexithymia is the difficulty in identifying and describing feelings. Several studies have suggested that chronic pain can be linked to alexithymia. The aims of this study were to determine the presence of alexithymia in a sample of Mexican individuals who attended public health services, to assess if alexithymia is higher in medically ill individuals with pain than in those without pain, and to determine which alexithymia dimensions are more affected by the presence of pain.

METHODS

Demographic and clinical features were evaluated in 250 Mexican outpatients of the General Hospital of Comalcalco, Tabasco. Pain was evaluated using the Visual Analogue Scale for Pain Assessment (VAS-P) and alexithymia was evaluated using the Toronto Alexithymia Scale (TAS-20).

RESULTS

38.8% of the sample was identified with probable/definite alexithymia and up to 61.2% of individuals were currently experiencing pain. Individuals with pain exhibited higher scores in the TAS-20 dimensions: difficulty describing feelings (p = 0.02), difficulty identifying feelings (p < 0.001) and higher total TAS-20 score (p < 0.001). Also, Probable/definite alexithymia was more frequently reported in individuals with pain (49% vs. 21.6%, p < 0.001).

CONCLUSIONS

Our results show that a large proportion of individuals who attend public health services in a Mexican population present pain. We also identified that pain could be associated with alexithymia, in particular with a difficulty in describing and identifying feelings. An early identification and treatment of alexithymia could help in reducing the clinical burden of chronic pain in Mexican outpatients.

Genetic and epigenetic architecture of Obsessive-Compulsive Disorder: In search of possible diagnostic and prognostic biomarkers

Obsessive-Compulsive Disorder (OCD) is a prevalent and severe clinical condition whose hallmarks are excessive, unwanted thoughts (obsessions) and repetitive behaviors (compulsions). The onset of symptoms generally occurs during pre-adult life and typically affects subjects in different aspects of their life's, compromising social and professional relationships. Although robust evidence suggests a genetic component in the etiopathogenesis of OCD, the causes of the disorder are still not completely understood. It is thus of relevance to take into account how genes interact with environmental risk factors, thought to be mediated by epigenetic mechanisms. We here provide an overview of genetic and epigenetic mechanisms of OCD, focusing on the modulation of key central nervous system genes, in the attempt to suggest possible disease biomarkers.

Prenatal androgen exposure causes a sexually dimorphic transgenerational increase in offspring susceptibility to anxiety disorders

If and how obesity and elevated androgens in women with polycystic ovary syndrome (PCOS) affect their offspring's psychiatric health is unclear. Using data from Swedish population health registers, we showed that daughters of mothers with PCOS have a 78% increased risk of being diagnosed with anxiety disorders. We next generated a PCOS-like mouse (F₀) model induced by androgen exposure during late gestation, with or without diet-induced maternal obesity, and showed that the first generation (F₁) female offspring develop anxiety-like behavior, which is transgenerationally transmitted through the female germline into the third generation of female offspring (F₃) in the androgenized lineage. In contrast, following the male germline, F₃ male offspring (mF₃) displayed anxiety-like behavior in the androgenized and the obese lineages. Using a targeted approach to search for molecular targets within the amygdala, we identified five differentially expressed genes involved in anxiety-like behavior in F₃ females in the androgenized lineage and eight genes in the obese lineage. In mF₃ male offspring, three genes were dysregulated in the obese lineage but none in the androgenized lineage. Finally, we performed in vitro fertilization (IVF) using a PCOS mouse model of continuous androgen exposure. We showed that the IVF generated F₁ and F₂ offspring in the female germline did not develop anxiety-like behavior, while the F₂ male offspring (mF₂) in the male germline did. Our findings provide evidence that elevated maternal androgens in PCOS and maternal obesity may underlie the risk of a transgenerational transmission of anxiety disorders in children of women with PCOS.

5-HTTLPR and COMT Val158Met are not associated with alexithymia: New evidence and meta-analyses

BACKGROUNDS

Alexithymia refers to the difficulties in identifying and describing one's own emotions, lacking of imagination, and an externally oriented thinking style. Studies up to date have examined the associations of 5-HTTLPR and COMT Val158Met polymorphisms with alexithymia. However, the previous findings were mixed.

METHODS

We replicated the associations by scoring on alexithymia with the 20-item Toronto Alexithymia Scale and genotyping the polymorphisms of 5-HTTLPR and COMT Val158Met in a large population of college students (N = 1698). Moreover, we also meta-analyzed the associations with five samples (N = 7517) for the 5-HTTLPR and with five samples (N = 2186) for the COMT Val158Met.

RESULTS

Neither the replicated study nor the meta-analyses indicated the 5-HTTLPR and COMT Val158Met were associated with alexithymia.

CONCLUSIONS

The findings suggest that the 5-HTTLPR and COMT Val158Met polymorphisms are not associated with alexithymia. However, genetic-environmental studies with different ethnicity and psychopathology should be carried in future.

Alexithymia and Psychopathology in Patients Suffering From Inflammatory Bowel Disease: Arising Differences and Correlations to Tailoring Therapeutic Strategies

Comorbidity with anxiety or depression is common in patients with Inflammatory Bowel Disease (IBD) as Crohn Disease (CD) and Ulcerative Colitis (UC). Data suggest that the cognitive construct of alexithymia has high prevalence in people suffering from anxiety and mood disorders and even in people with IBD. Most studies have investigated mainly anxiety and depression, considering IBD population as a homogeneous group of patients. Little evidence shows the impact of alexithymia on the course of IBD. We evaluated a broad spectrum of psychopathological symptoms and alexithymia levels in a group of outpatients affected by IBD in clinical remission, comparing CD and UC and investigating the relationship with clinical and socio-demographic variables. One hundred and seventy IBD outpatients were screened by using the Hospital Anxiety Depression Scale (HADS), the Self-report Symptom Inventory-90-Revised (SCL-90-R) and the Toronto Alexithymia Scale (TAS-20). A high prevalence of anxious and depressive symptoms (42.35 and 25.8% respectively) together with alexithymia (31.76%) was confirmed. CD patients experienced high levels of depression (HADS Depression 35.2% p = 0.034; SCL-90-R mean 1.39 p < 0.001), somatisation (SCL-90-R mean 1.04 p < 0.001), obsessive-compulsive symptoms (SCL-90-R mean 1.2 p < 0.001), and global severity (SCL-90-R mean 1.15 p < 0.001). There is no statistical difference in the prevalence of alexithymia in both subpopulations. The levels of alexithymia are correlated to the levels of anxiety (HADS Anxiety rs = 0.516 p < 0.001), depression (HADS Depression rs = 0.556 p < 0.001; SCL-90-R rs = 0.274 p = 0.001), somatisation (SCL-90-R rs = 0.229 p = 0.005), obsessive-compulsive symptoms (SCL-90-R rs = 0.362 p < 0.001), and global severity (SCL-90-R rs = 0.265 p = 0.001). Furthermore, alexithymia is associated with a delay of diagnosis of IBD, poly-therapies and greater IBD extension. Older age, female gender, greater IBD extension, surgery, and delay of diagnosis seem to be related to a high prevalence of psychopathological symptoms such as anxiety, depression, somatisation, and obsessive-compulsive symptoms. Psychopathological symptoms and high levels of alexithymia are frequent in IBD patients and seem to be related to a high risk of poor clinical outcome. CD patients could be considered at higher risk of mental comorbidity. A more comprehensive psychiatric assessment, including alexithymia, and an integrated treatment of underlying conditions, must be taken into account in order to improve the global prognosis of the disease.