**3. Current available treatment options for OCD**

is either unrealistic or excessive. Obsessions and/or compulsions must take up at least 1 h a day, and though it may relieve their anxiety, it should not be pleasurable to the patient. In addition to the time component, the obsessions-compulsions should cause significant impairment in social or occupational functioning. The OCD symptoms should not be due to a substance or another disorder. Specifiers for OCD in the DSM 5 include the degree of insight (good, fair, poor, absent,

The 12-month prevalence of OCD in the United States is 1.2%, with similar prevalence internationally (1.1–1.8%). Females are affected at a slightly higher rate than males in adulthood; although males are more commonly affected in childhood. The mean age at onset of OCD is 19.5 years and 25% of cases start by 14 years old. Onset after 35 years is unusual but does occur. Males have an earlier age of onset than females; nearly 25% of males have onset before the age of 10. The onset of symptoms is typically gradual; however, acute onset has also been reported [1]. If OCD is untreated, the course is usually chronic, often with waxing and waning symptoms. Some have an episodic course and a minority has a deteriorating course. Without treatment, remission rates in adults are low (i.e. 20%). Onset in childhood or adolescence can lead to a lifetime of OCD. However, 40% of individuals with childhood or adolescent onset of OCD may experience remission by early adulthood. The course of OCD is often complicated by the co-occurrence of other disorders. Compulsions are more easily diagnosed in children than obsessions, because compulsions are observable. However, most children have both [1].

Greater internalizing symptoms, higher negative emotionality, and behavioral inhibition in childhood are possible temperamental risk factors. Physical and sexual abuse in childhood and other stressful or traumatic events have been associated with an increased risk for developing OCD. Some children develop the sudden onset of OCD symptoms after streptococcal infection, and subsequently it is not distinguishable from OCD for the duration of their lives. In others, it has more motor symptoms and is amenable to antibiotic treatment if it is treated immediately.

Most OCD patients (76%) have a lifetime history of another anxiety disorder. Specifically, 63% have lifetime history of mood disorder, 41% have major depressive disorder, 23–32% has comorbid obsessive-compulsive personality disorder, 29% have lifetime history of tic disorder, and 12% have schizophrenia. Additional common diagnoses include bipolar, anorexia,

OCD may be the most heritable psychiatric condition, with a monozygotic twin concordance rate of 0.52 and a dizygotic concordance rate of 0.21, with overall heritability for OCD estimated

delusional beliefs) and tic related [1].

90 Transcranial Magnetic Stimulation in Neuropsychiatry

**2. Epidemiology**

**2.1. Prognostic factors**

**2.2. Comorbidities**

**2.3. Heritability**

bulimia and Tourette's [1].

At the present time**,** exposure and response prevention should probably be the first line treatment for non-comorbid OCD. Pharmacologic interventions with significant evidence for efficacy, specifically with 8–12 weeks of medication results with greater than 30% improvement for 40–60% of OCD patients include several selective serotonin reuptake inhibitors: Fluoxetine, Paroxetine, Fluvoxamine and Sertraline in the USA; Citalopram and Escitalopram in Europe; and the tricyclic, Clomipramine.

Neurosurgery has shown promising outcomes where 58–67% of patients showed marked improvement in numerous studies even for patients who have refractory OCD (failed three medications and had 6 months of exposure and response prevention). The primary ablation anatomical targets are the fiber tracts that connect the cortex to thalamic nuclei, the anterior limb of the internal capsule and the cingulate gyrus. Nevertheless, neurosurgical procedures also yield reports of transient and persistent adverse effects [4].

Deep brain stimulation (DBS) has several advantages over ablation. Surgeons using DBS can potentially achieve a clinical effect without producing an irreversible lesion. The efficacy of ablative lesions appears to be similar to DBS.
