A 22 years old woman presents with complaints of intense urge to shower. She spends hours showering and finds it difficult to get out of shower. She is also following same order of actions while bathing, scrubbing every body part 3 times in the same order. She is aware that this is abnormal but she becomes very anxious if she tries to break this pattern. She works as receptionist and is frequently late to her job because of this habit. She gets along well with friends at work. The drug of choice for treating her condition is:

**Core Concept**
The patient's symptoms describe a pattern of repetitive behavior, intense anxiety when attempting to break the pattern, and a significant impact on daily functioning. This presentation is characteristic of a Obsessive-Compulsive Disorder (OCD), a neurodevelopmental disorder involving intrusive thoughts (obsessions) and repetitive behaviors (compulsions).

**Why the Correct Answer is Right**
The patient's symptoms of excessive showering and following a rigid routine are classic examples of compulsions. The underlying mechanism involves an imbalance in the brain's neurotransmitter systems, particularly serotonin and dopamine. The drug of choice for treating OCD is a selective serotonin reuptake inhibitor (SSRI), which increases the levels of serotonin in the synaptic cleft, thereby reducing the frequency and severity of obsessive thoughts and compulsive behaviors.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because while benzodiazepines may provide temporary relief from anxiety, they are not the first-line treatment for OCD and can lead to dependence and withdrawal symptoms.
* **Option B:** This option is incorrect because antipsychotics, although sometimes used off-label for treating OCD, are not the preferred first-line treatment due to their potential side effects and the availability of more effective and safer options like SSRIs.
* **Option C:** This option is incorrect because mood stabilizers, primarily used in treating bipolar disorder, are not typically used as a first-line treatment for OCD.

**Clinical Pearl / High-Yield Fact**
SSRIs are the preferred first-line treatment for OCD due to their efficacy and relatively favorable side effect profile. It's essential for clinicians to educate patients about the potential benefits and risks of these medications and monitor their response closely.

**Correct Answer:** C. Fluoxetine

✓ Correct Answer: B. Fluvoxamine