Genetic and environmental influences on obsessive-compulsive behaviour across development: a longitudinal twin study

Associations Between Suicidality and Interoception in Obsessive-Compulsive Disorder

Background

Individuals with obsessive-compulsive disorder (OCD) are at increased risk for suicide. One potential risk factor is interoceptive sensibility (IS), which is one's subjective experience of bodily sensations. The current study examined the relationship between IS and current suicidal ideation and lifetime history of suicide attempt, controlling for relevant covariates.

Methods

Participants (N = 145) were a clinical sample of individuals with OCD from the New York City area. A clinical rater administered a diagnostic interview and an OCD severity assessment, and participants completed questionnaires about demographics, IS, and suicidality.

Results

Current suicidal ideation was associated with reduced trusting of the body, and lifetime history of suicide attempt was related to greater general awareness of sensation. These associations remained significant after controlling for covariates.

Conclusions

These results suggest that specific facets of IS may be associated with specific domains of suicidality. Decreased body trusting may represent a feeling of disconnection from the body that facilitates desire for death. Increased noticing of bodily sensations may lead to greater mental pain, which could interact with deficits in emotion regulation to increase risk for suicide attempt. Further research on the relationships between IS and suicidality in OCD is warranted.

The impact of childhood trauma on perceived stress and personality in patients with obsessive-compulsive disorder: A cross-sectional network analysis

OBJECTIVE

Little is known about the role of childhood experiences in the development of obsessive-compulsive disorder (OCD). However, the influence of childhood experiences on personality, behavior, and perceived stress may vary between OCD patients and healthy individuals. The objective of this study was to use network analysis to explore the relationship between childhood trauma, personality, perceived stress, and symptom dimensions, thus finding the difference between patients' and healthy people's network.

METHODS

488 patients with OCD and 210 healthy volunteers were recruited. All of them were assessed with the Obsessive-Compulsive Inventory - Revised (OCI-R), the Perceived Stress Scale-10, the NEO Five-Factor Inventory and the Early Trauma Inventory Self-Report Short Form. Network analysis was conducted and the centrality indices were calculated. Network comparison test was performed.

RESULTS

In patients' network, the Obsession and the Ordering behavior were the most important nodes among the OCI-R. The perceived stress showed the strongest strength centrality of all nodes and positive correlation with the Obsession and Neuroticism. Network comparison test results indicated a statistically significant difference between network structure, and post-hoc analysis found five edges significantly differed between patients and healthy controls, mainly on Obsession and Washing behaviors.

CONCLUSIONS

Emotional abuse was considered significant in both networks due to its higher strength centrality. Meanwhile, perceived stress was found to be more significant in the patient network and exhibited stronger associations with obsession. The obsessive thoughts and washing behavior were different among patients and healthy controls, which brought new understanding to the pathopsychological mechanisms of OCD.

The genetic epidemiology of obsessive-compulsive disorder: a systematic review and meta-analysis

The first systematic review and meta-analysis of obsessive-compulsive disorder (OCD) genetic epidemiology was published approximately 20 years ago. Considering the relevance of all the studies published since 2001, the current study aimed to update the state-of-art knowledge on the field. All published data concerning the genetic epidemiology of OCD from the CENTRAL, MEDLINE, EMBASE, BVS, and OpenGrey databases were searched by two independent researchers until September 30, 2021. To be included, the articles had to fulfill the following criteria: OCD diagnosis provided by standardized and validated instruments; or medical records; inclusion of a control group for comparison and case-control, cohort or twin study designs. The analysis units were the first-degree relatives (FDRs) of OCD or control probands and the co-twins in twin pairs. The outcomes of interest were the familial recurrence rates of OCD and the correlations of OCS in monozygotic compared with dizygotic twins. Nineteen family, twenty-nine twin, and six population-based studies were included. The main findings were that OCD is a prevalent and highly familial disorder, especially among the relatives of children and adolescent probands, that OCD has a phenotypic heritability of around 50%; and that the higher OCS correlations between MZ twins were mainly due to additive genetic or to non-shared environmental components.

Preschool-onset OCD: A review of literature and clinical experience

Obsessive-compulsive disorder (OCD) has been described in preschool children as young as 2-3 years old. A preschool age onset of OCD has unique diagnostic and therapeutic challenges. In this article, the authors review published literature on preschool onset OCD and present data on preschool-onset OCD (age of onset ≤ 5 years) from clinical records at a tertiary care child and adolescent psychiatry center in India. Literature suggests that OCD that starts this early is phenomenologically similar to OCD in older individuals; however, it has very high rates of comorbidity and a family history of OCD. There is a paucity of data on course, treatment, and long-term outcome in this group. At their center, the authors found a 3% prevalence of preschool-onset OCD, with a male predominance (69%) and fairly high comorbidity rates (62%). Qualitative review highlighted delay in treatment seeking, poor follow-up rates, frequent use of pharmacological treatment, and a high remission rate in those treated adequately.

Concurrent and prospective associations of obsessive-compulsive symptoms with suicidality in young adults: A genetically-informative study

BACKGROUND

Obsessive-compulsive disorder (OCD) has been linked with elevated risk of suicidality. However, most previous studies have been cross-sectional, and little is known about the aetiology of the association between obsessive-compulsive symptoms (OCS) and suicidality in young adults.

METHODS

Participants were members of the Child and Adolescent Twin Study in Sweden, at ages 18 (n = 9,162) and 24 (n = 3,466). Twins completed self-report measures, including assessment of OCS, suicidal ideation, and suicidal attempts. Logistic regression models tested concurrent and prospective associations of total OCS and OCS dimensions with suicidality, with and without adjustment for depression and anxiety symptoms. Genetic models tested the extent to which the main phenotypic associations were accounted for by genetic and environmental influences.

RESULTS

Total OCS were significantly associated with concurrent reports of suicidality at age 18 and 24, even when controlling for depressive and anxiety symptoms. Taboo obsessions (e.g., sexual and aggressive thoughts) were more robustly associated with suicidality than other OCS dimensions, and prospectively predicted suicidality symptoms over time, even when controlling for baseline suicide attempts. Genetic factors accounted for most of the concurrent and longitudinal covariance between OCS and suicidality, with substantial non-shared environmental influences.

LIMITATIONS

We relied on self-report measures and did not include diagnostic assessment of OCD.

CONCLUSIONS

OCS, particularly taboo obsessions, are associated with significantly elevated risk of suicidality in late adolescence and early adulthood. This relationship is explained by a combination of common genetic liability and non-shared environmental effects, suggesting that effective OCS treatment might reduce suicidality risk in this group.

Identification of Gene Loci That Overlap Between Mental Disorders and Poor Prognosis of Cancers

Background: Co-morbid psychiatric disorders are common in patients with cancers, which make the treatment more difficult. Studying the connection between mental disease-related genes and the prognosis of cancers may potentially lead to novel therapeutic methods. Method: All mental disorders genes were selected from published articles. The correlations between the expression of these genes and the prognosis of different cancers were analyzed by starBase v2.0 and TIMER. The molecular functions, reactome pathways, and interactions among diverse genes were explored via the STRING tool. Results: 239 genes were identified for further survival analysis, 5 of which were overlapping genes across at least five cancer types, including RHEBL1, PDE4B, ANKRD55, EPHB2, and GIMAP7. 146 high-expression and 157 low-expression genes were found to be correlated with the unfavorable prognosis of diverse cancer types. Tight links existed among various mental disease genes. Besides, risk genes were mostly related to the dismal outcome of low-grade glioma (LGG) and kidney renal clear cell carcinoma (KIRC) patients. Gene Ontology (GO) and reactome pathway analysis revealed that most genes involved in various critical molecular functions and primarily related to metabolism, signal transduction, and hemostasis. Conclusions: To explore co-expression genes between mental illnesses and cancers may aid in finding preventive strategies and therapeutic methods for high-risk populations and patients with one or more diseases.

Towards a Clinically Valid Mechanistic Assessment of Exposure and Response Prevention: Preliminary Utility of an Exposure Learning Tool for Children with OCD

Despite advances in understanding mechanisms underlying fear processes, there remains a significant gap between insights produced via laboratory assessment and concrete tools for harnessing these insights in clinical practice. In addressing this gap, researchers would ideally introduce tools that are feasible for patients in clinical practice, easily disseminated to practitioners, and clinically useful. We present pilot data on the Exposure Experience Questionnaire (EEQ), a brief measure designed to assess exposure learning mechanisms. Ten children (ages 8-15) with a primary diagnosis of obsessive-compulsive disorder (OCD) underwent exposure and response prevention in which they completed weekly exposures in clinic and at home. During each exposure, children completed an exposure practice form which included the EEQ. Results suggest the preliminary feasibility and internal consistency of this measure, with comparable utility in clinic and home settings. The EEQ was associated in the expected direction with slope of OCD symptoms, such that greater exposure learning in both clinic and homework exposures predicted improved outcome. Although limited by small sample size, these data support the continued research on the feasibility and utility of the EEQ and suggest that quantifying learning processes following exposure may be a useful addition to mechanistic research in OCD.

Abnormal Regional Homogeneity in Patients With Obsessive-Compulsive Disorder and Their Unaffected Siblings: A Resting-State fMRI Study

Objective: Previous studies suggest that abnormal brain structure and function may be neuroimaging endophenotypes of obsessive-compulsive disorder (OCD). Comparing the intrinsic brain activity of OCD patients and their unaffected siblings will help to further understand the susceptibility to, and pathological mechanisms of, OCD. We used a case-control study design aiming to establish whether the abnormal regional homogeneity (ReHo) found in OCD patients also exists in their unaffected siblings. Method: Fifteen unmedicated OCD patients, 15 of their unaffected siblings, and 30 healthy controls (HCs) received resting-state functional magnetic resonance imaging (r-s fMRI) scanning and clinical evaluation. We used the ReHo method to analyze the inter-regional synchronized activity of all participants. One-way analysis of covariance with post hoc tests was used to compare the ReHo maps across groups. A Pearson correlation analysis was conducted to assess the correlations between clinical characteristics and abnormal ReHo in OCD patients. Results: Relative to HCs, OCD patients and their unaffected siblings showed overlapping higher ReHo values in the right dorsolateral prefrontal cortex (DLPFC). Patients with OCD showed increased ReHo in left middle frontal gyrus (MFG) relative to both their unaffected siblings and HCs. In addition to the right DLPFC and left MFG, OCD patients, compared with HCs, also showed abnormal ReHo in other regions, including higher ReHo in the right superior parietal cortex and lower ReHo in the left inferior parietal cortex, right parahippocampal region, left thalamus, and right inferior temporal cortex. Compared with HCs, the unaffected siblings of patients with OCD had significantly higher ReHo in the right inferior parietal cortex, right MFG, and right supplementary motor area. There was no association between clinical symptoms and abnormal ReHo values in OCD patients. Conclusions: This study found overlapping higher ReHo values in the right DLPFC of OCD patients and their unaffected siblings. Our results suggest that the higher ReHo in the right DLPFC may be a potential neuroimaging endophenotype, which may reflect an increased genetic risk of OCD.

Prevalence and heritability of body dysmorphic symptoms in adolescents and young adults: a population-based nationwide twin study

BACKGROUND

Body dysmorphic disorder (BDD) usually begins during adolescence but little is known about the prevalence, etiology, and patterns of comorbidity in this age group. We investigated the prevalence of BDD symptoms in adolescents and young adults. We also report on the relative importance of genetic and environmental influences on BDD symptoms, and the risk for co-existing psychopathology.

METHODS

Prevalence of BDD symptoms was determined by a validated cut-off on the Dysmorphic Concerns Questionnaire (DCQ) in three population-based twin cohorts at ages 15 (n = 6968), 18 (n = 3738), and 20-28 (n = 4671). Heritability analysis was performed using univariate model-fitting for the DCQ. The risk for co-existing psychopathology was expressed as odds ratios (OR).

RESULTS

The prevalence of clinically significant BDD symptoms was estimated to be between 1 and 2% in the different cohorts, with a significantly higher prevalence in females (1.3-3.3%) than in males (0.2-0.6%). The heritability of body dysmorphic concerns was estimated to be 49% (95% CI 38-54%) at age 15, 39% (95% CI 30-46) at age 18, and 37% (95% CI 29-42) at ages 20-28, with the remaining variance being due to non-shared environment. ORs for co-existing neuropsychiatric and alcohol-related problems ranged from 2.3 to 13.2.

CONCLUSIONS

Clinically significant BDD symptoms are relatively common in adolescence and young adulthood, particularly in females. The low occurrence of BDD symptoms in adolescent boys may indicate sex differences in age of onset and/or etiological mechanisms. BDD symptoms are moderately heritable in young people and associated with an increased risk for co-existing neuropsychiatric and alcohol-related problems.

Heritability of hoarding symptoms across adolescence and young adulthood: A longitudinal twin study

Background

Twin studies of hoarding symptoms indicate low to moderate heritability during adolescence and considerably higher heritability in older samples, suggesting dynamic developmental etiological effects. The aim of the current study was to estimate the relative contribution of additive genetic and environmental effects to hoarding symptoms during adolescence and young adulthood and to estimate the sources of stability and change of hoarding symptoms during adolescence.

Methods

Univariate model-fitting was conducted in three cohorts of twins aged 15 (n = 7,905), 18 (n = 2,495) and 20–28 (n = 6,218). Longitudinal analyses were conducted in a subsample of twins for which data on hoarding symptoms was available at both age 15 and 18 (n = 1,701).

Results

Heritability estimates for hoarding symptoms at ages 15, 18 and 20–28 were 41% (95% confidence interval [CI]: 36–45%), 31% (95% CI: 22–39%) and 29% (95% CI: 24–34%) respectively. Quantitative sex-differences emerged in twins aged 15 at which point the heritability in boys was 33% (95% CI: 22–41%) and 17% (95% CI: 0–36%) in girls. Shared environmental effects played a negligible role across all samples with the exception of girls aged 15 where they accounted for a significant proportion of the variance (22%; 95% CI 6–36%). The longitudinal bivariate analyses revealed a significant phenotypic correlation of hoarding symptoms between ages 15 and 18 (0.40; 95% CI: 0.36–0.44) and a strong but imperfect genetic correlation (0.75; 95% CI: 0.57–0.94). The bivariate heritability was estimated to 65% (95% CI: 50–79%).

Conclusions

Hoarding symptoms are heritable from adolescence throughout young adulthood, although heritability appears to slightly decrease over time. Shared environmental effects contribute to hoarding symptoms only in girls at age 15. The stability of hoarding symptoms between ages 15 and 18 is largely explained by genetic factors, while non-shared environmental factors primarily have a time-specific effect. The findings indicate that dynamic developmental etiological effects may be operating across the life span.

Aetiological influences on stability and change in emotional and behavioural problems across development: a systematic review

Emotional and behavioural problems in childhood and adolescence can be chronic and are predictive of future psychiatric problems. Understanding what factors drive the development and maintenance of these problems is therefore crucial. Longitudinal behavioural genetic studies using twin, sibling or adoption data can be used to explore the developmental aetiology of stability and change in childhood and adolescent psychopathology. We present a systematic review of longitudinal, behavioural genetic analyses of emotional and behavioural problems between ages 0 to 18 years. We identified 58 studies, of which 19 examined emotional problems, 30 examined behavioural problems, and 9 examined both. In the majority of studies, stability in emotional and behavioural problems was primarily genetically influenced. Stable environmental factors were also widely found, although these typically played a smaller role. Both genetic and environmental factors were involved in change across development. We discuss the findings in the context of the wider developmental literature and make recommendations for future research.

Traumatic and Adverse Attachment Childhood Experiences are not Characteristic of OCD but of Depression in Adolescents

We investigated whether adverse attachment experience might contribute to the development of obsessive-compulsive disorder (OCD). We interviewed 100 adolescents, 25 each with primary OCD, depressive disorder (DD), OCD plus DD and general population controls (CTRs) using the adult attachment interview to assess attachment experiences (AEs), including traumatic and adverse AE (TAE). Adolescents with OCD, OCD+DD and DD had little evidence of secure base/safe haven parental behaviour and their childhood attachment needs judged to be rejected as compared to the controls. Overprotection was not characteristic of OCD, and parents using the child for their own needs (elevated levels of involving/role reversal) occurred only in DD, with low levels in OCD, OCD+DD and CTR. Traumatic experiences, often multiple, and/or attachment related were reported significantly more often in the DD group, and was less common in OCD+DD, CTR and particularly in the OCD group. In OCD, little TAE was reported and adverse AE were less serious and seem unlikely to contribute directly to OCD aetiology. In DD and to some degree in OCD+DD serious AE/TAE may have some etiological significance for the depressive states.

From Thought to Action: How the Interplay Between Neuroscience and Phenomenology Changed Our Understanding of Obsessive-Compulsive Disorder

The understanding of obsessive-compulsive disorder (OCD) has evolved with the knowledge of behavior, the brain, and their relationship. Modern views of OCD as a neuropsychiatric disorder originated from early lesion studies, with more recent models incorporating detailed neuropsychological findings, such as perseveration in set-shifting tasks, and findings of altered brain structure and function, namely of orbitofrontal corticostriatal circuits and their limbic connections. Interestingly, as neurobiological models of OCD evolved from cortical and cognitive to sub-cortical and behavioral, the focus of OCD phenomenology also moved from thought control and contents to new concepts rooted in animal models of action control. Most recently, the proposed analogy between habitual action control and compulsive behavior has led to the hypothesis that individuals suffering from OCD may be predisposed to rely excessively on habitual rather than on goal-directed behavioral strategies. Alternatively, compulsions have been proposed to result either from hyper-valuation of certain actions and/or their outcomes, or from excessive uncertainty in the monitoring of action performance, both leading to perseveration in prepotent actions such as washing or checking. In short, the last decades have witnessed a formidable renovation in the pathophysiology, phenomenology, and even semantics, of OCD. Nevertheless, such progress is challenged by several caveats, not least psychopathological oversimplification and overgeneralization of animal to human extrapolations. Here we present an historical overview of the understanding of OCD, highlighting converging studies and trends in neuroscience, psychiatry and neuropsychology, and how they influenced current perspectives on the nosology and phenomenology of this disorder.