Obsessive-compulsive and related disorders.

Obsessive-compulsive and related disorders (OCRDs), sometimes referred to as obsessive-compulsive spectrum disorders, cause significant impairment and share similar features across several domains, including clinical course, risk factors, and response to treatment. Generally, individuals meeting criteria for one or more OCRDs present with symptoms focused on preoccupations and repetitive behaviors. Sex differences emerge in the clinical presentation of OCRDs, and the associated. Literature emphasizes the importance of considering sex when investigating causal factors, prognosis, and outcomes of OCRDs. Understanding sex-specific phenotypes can help clinicians and healthcare providers to screen for and recognize relevant symptoms, and to create a more tailored approach for care of males and females. In this chapter, we review sex differences in obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), hoarding disorder, trichotillomania (hair-pulling disorder), and excoriation (skin-picking) disorder. Here, we provide an updated review on the sex differences in the prevalence, symptomatology, illness course and prognosis, comorbidity, risk factors, and treatment outcomes associated with OCRDs, and highlight gaps in the current literature on sex differences in these disorders.

The association of HTR2A polymorphisms with obsessive-compulsive disorder and its subtypes: A meta-analysis.

BACKGROUND: Genetic risk factors that contribute to obsessive-compulsive disorder (OCD) have yet to be elucidated. Historically, serotonergic dysfunction has been implicated. Evidence from the literature points towards the serotonin receptor 2A gene (HTR2A) as a primary candidate. Our meta-analysis investigated whether polymorphisms in HTR2A are associated with OCD or its subtypes, based on sex and age of onset. METHODS: Studies employing case-control or family-based designs were systematically searched, and those meeting eligibility underwent quality assessment, resulting in 18 studies. A random-effects meta-analysis using standard inverse-variance weighting to compute odds ratio (OR) was conducted. To examine sensitivity, results were also obtained using a more conservative statistical method. RESULTS: Three HTR2A variants were identified: T102C, G-1438A, and C516T. T102C and G-1438A were analyzed together due to strong linkage disequilibrium, where the 102T allele co-occurs with -1438A allele. Results reported as OR [95%CI] showed that the T/A allele were significantly associated with OCD, 1.14 [1.01, 1.29]. After stratification, results remained significant for females, 1.20 [1.00, 1.45], and early-onset OCD, 1.27 [1.02, 1.58], but not males, 1.06 [0.91, 1.23]. No associations were found for late-onset OCD, 0.98 [0.70, 1.37], or C516T, 1.22 [0.14, 10.37], but conclusions cannot be drawn from two studies. LIMITATIONS: Associations no longer reached significance with the conservative statistical approach. HTR2A alone cannot explain OCD complexity and limited samples reporting genetic data according to subtypes. CONCLUSIONS: These results suggest a possible association of HTR2A polymorphisms with OCD, but further investigations considering sex and age of onset with larger samples is needed.

Effect of Gonadal Hormones on Neurotransmitters Implicated in the Pathophysiology of Obsessive-Compulsive Disorder: A Critical Review.

Obsessive-compulsive disorder (OCD) is a relatively common neuropsychiatric disorder affecting between 1.6 and 3.2% of the population. A number of studies have previously reported increased incidence of OCD, or exacerbation of preexisting symptoms in females during reproductive events. Since these periods are known to involve fluctuating levels of gonadal hormones, these steroids have been suggested to be involved in modulating the course of the disorder. However, to date, only a few studies have measured hormone levels and obsessive-compulsive (OC) symptoms concurrently; thus, direct evidence for this relationship is limited. In turn, investigations into neurotransmission in OC individuals have been more extensive, and have implicated the serotonergic, dopaminergic, and glutamatergic neurotransmitter systems in OCD pathology. There is evidence suggesting that reproductive hormones estrogens and progesterone can modulate neurotransmission in the aforementioned signaling pathways by regulating the expression of receptors and channels, as well as the synthesis and release of the neurotransmitter itself. Overall, estrogen and progesterone appear to enhance serotonin signaling, which has been associated with improved OC symptoms. The effect of the gonadal hormones in dopaminergic and glutamatergic signaling is much more variable, highlighting the need for further research in this field. The existing evidence shows that gonadal hormones can have profound impacts on neurotransmission in the brain, leading to the conclusion that the hormonal fluctuations during reproductive events are a plausible factor contributing to the change in OCD course during these times.

The need for inclusion of sex and age of onset variables in genetic association studies of obsessive-compulsive disorder: Overview.

Obsessive-compulsive disorder (OCD) is a heterogeneous mental disorder that significantly impairs an individual's functioning. The candidate gene approach has proven to be a useful tool in investigating potential risk genes for OCD, but genetic studies have been largely inconclusive. Etiologically distinct forms of obsessive-compulsive disorder based on sex and age of onset have been identified, yet many genetic studies fail to examine the association by these subtypes. Due to the sexually dimorphic nature of the disorder, positive associations have been found with OCD in males only, suggesting the potential for identifying risk genes that contribute to OCD in women, such as perinatal OCD. This review includes a brief overview of the disorder and its subtypes, with a current update on candidate genes that may contribute to OCD using single nucleotide polymorphisms (SNPs) and genome wide association studies (GWAS).