Obsessive Compulsive Disorder

Abstract

OCD is the fourth most common neuropsychiatric disorder with lifetime prevalence estimates of 0.4-3.5%. Family and twin studies suggest a strong genetic component, and molecular genetic studies are being carried out to identify genes contributing risk to OCD. It is postulated as a frontal-striatal disorder and functional neuroimaging studies provide a strong support for the dysfunction of cortico-striatal-thalamic-cortical neurocircuit. OCD can be secondary to a variety of medical conditions that range from deteriorative neurological illness, to head injury, and to autoimmune disorders. Few reports and no controlled studies exist in the treatment of acquired/secondary OCD. Both CBT and pharmacotherapy are effective fi rst-line treatment modalities for OCD. Brain stimulation and/or psychosurgery have been tried with varying success in treatment of refractory OCD. Environmental, genetic, and clinical factors interact in a complex fashion in the individual patient. This chapter will examine OCD from the medical perspective.Keywords Obsessive compulsive disorder · Cortical-striatal-thalamo-cortical circuit · Genetics · Neuroimaging · Autoimmune · Treatment IntroductionAs defi ned in DSM-5, obsessive compulsive disorder (OCD) is characterized by obsessions (recurrent, unwanted, and distressing thoughts, images, or impulses) and/or compulsions (complex, repetitive, rule-governed behaviors that the patient feels driven to perform). Patients usually try to actively dismiss obsessions or neutralize them by seeking reassurance, avoiding situational triggers, or engaging in compulsions. Obsessions and compulsions are maladaptive, and lead to impaired functioning. They typically center on four themes: contamination, sexual/aggressive/checking, and ordering and symmetry. Common compulsions include excessive cleaning, checking behaviors, ordering and arranging rituals, counting, and repeating routine activities. Compulsions usually involve observable behaviors (e.g., hand-washing) but may also consist of covert mental rituals (e.g., counting, or ritualized performance of mental math). Symptom themes can vary over the course of the illness but those without a personal or family history of tics are more likely to have more frequent contamination themes. In the DSM-5, hoarding has been categorized as a distinct disorder, and is no longer considered a specifi c form of OCD. The addition of a separate diagnosis is supported by extensive research suggesting that, although the two disorders can co-occur, patients with symptoms of hoarding have a number of signifi cant phenomenological differences than those with OCD, including distinct cognitive processes, reinforcement patterns, and response to treatments commonly used to address symptoms of OCD ( 1 ).The proposed lifetime prevalence of OCD in the pediatric and adult population ranges from 0.4 to 3.5% in national and international epidemiological samples ( 2 -7 ). Approximately half of all OCD patients fi rst present in childhood, before age 15 ( 8 ) with biphasic symptom p...

Impact of Early Life Stress on Neurobiological Vulnerability to Obsessive-Compulsive Disorder: Early Life Stress & Neurobiological OCD Risk

“…Childhood-onset OCD appears to be especially vulnerable to the effects of stress, though the precise nature of this relationship remains unknown. Nevertheless, the impact of stress on OCD cannot be underestimated, with studies suggesting a link between early life stress or trauma and the emergence of psychiatric symptoms [38, 39]. Furthermore, acute brain trauma, while less common, can cast a long shadow over OCD pathogenesis, complicating the complex web of causality.…”

“This Is a Disease” and “Disease Has No Sin”: Discourse Constructions of Individuals With Obsessive–Compulsive Disorder With Regard to Being Diagnosed

“…This included various symptoms such as hair pulling, skin picking, and hoarding (APA, 2013). Despite the biomedical explanation suggesting that obsessive thoughts may be caused by chemical imbalances in the brain or a genetic predisposition (Dhuri & Parkar, 2016;Nakao et al, 2014;Norman et al, 2021), today, cognitivebehavioral and medical explanations have come to dominate the public discourse surrounding OCD (Rachman, 1997;Salkovskis, 1985Salkovskis, , 1989. From this perspective, obsessions are defined as individuals' appraisal of their distressing thoughts as dangerous, leading them to attempt to control such thoughts (Hacıömeroglu, 2008;McKay et al, 2004).…”

“…Unwanted thoughts and repetitive behavior, which are currently defined as distressing experiences that a person cannot stop thinking about and/or acting out, despite being aware of their unusual nature, can be extremely painful for those who experience them (APA, 2013; National Institute of Mental Health, 2019). Despite their high prevalence, affecting approximately 2%–3% of the general population, these experiences often go unreported, up to a rate of around 20%, due to shame and guilt that individuals feel for having these so-called “bizarre” experiences (APA, 2013; Bellia et al, 2021; Fineberg et al, 2013; Murphy et al, 2016).…”