OCD is primarily associated with dysregulation of the serotonergic system, particularly involving the serotonin transporter (SERT) and serotonin receptors.

SSRIs are the first-line pharmacological treatment for OCD due to their efficacy and relatively favorable side effect profile.

Fluoxetine (Prozac) is often the initial SSRI of choice for OCD due to its long half-life, low side effect profile, and demonstrated efficacy.

SSRIs work by blocking the reuptake of serotonin in the synaptic cleft, leading to increased synaptic serotonin levels and enhanced serotonergic signaling.

Sexual dysfunction, including decreased libido and erectile dysfunction, is a common side effect of SSRIs.

Long-term treatment with SSRIs for at least 12-18 months is generally recommended for OCD to achieve optimal outcomes.

Atypical antipsychotics, such as risperidone and olanzapine, are often used in combination with SSRIs to enhance efficacy in treatment-resistant OCD.

Atypical antipsychotics work by blocking dopamine D2 receptors, which may help reduce compulsive behaviors and improve OCD symptoms.

Weight gain is a common side effect of atypical antipsychotics, particularly olanzapine and clozapine.

Benzodiazepines are typically used for short-term relief of anxiety symptoms in OCD, but they are not recommended for long-term use due to their potential for dependence and abuse.

Benzodiazepines have been associated with an increased risk of suicidal ideation and behavior, particularly in patients with a history of depression or suicidal thoughts.

Benzodiazepines should be discontinued gradually over several weeks to minimize the risk of withdrawal symptoms, such as rebound anxiety, insomnia, and seizures.

Long-term benzodiazepine use can lead to the development of tolerance, increased risk of cardiovascular disease, and impaired cognitive function.

The primary goal of pharmacotherapy in OCD is to reduce the severity of compulsions and obsessions, thereby improving the patient's quality of life and preventing relapse.

Pharmacotherapy for OCD may be limited by the potential for side effects, limited long-term efficacy, and the risk of medication dependence.