A 19-year-old man comes to the office due to overwhelming "stress." The patient recently started working as a busboy in a restaurant and is afraid that he will be fired because he is often late. He says, "I live close to work, but the drive takes me a long time-I have to make a lot of stops." Every time the patient drives over a bump in the road, he is convinced that he has accidentally run over someone and immediately pulls over to check underneath the car. Even at work, he is unable to focus and must frequently check the news to see if any hit-and-run accidents have been reported. The patient has no previous psychiatric history, suicide attempts, or violent behavior; family history is notable for schizophrenia in a maternal uncle. The first-line pharmacotherapy for this patient's current condition primarily affects which of the following neurotransmitters?

Question

A 19-year-old man comes to the office due to overwhelming "stress."  The patient recently started working as a busboy in a restaurant and is afraid that he will be fired because he is often late.  He says, "I live close to work, but the drive takes me a long time-I have to make a lot of stops."  Every time the patient drives over a bump in the road, he is convinced that he has accidentally run over someone and immediately pulls over to check underneath the car.  Even at work, he is unable to focus and must frequently check the news to see if any hit-and-run accidents have been reported.  The patient has no previous psychiatric history, suicide attempts, or violent behavior; family history is notable for schizophrenia in a maternal uncle.  The first-line pharmacotherapy for this patient's current condition primarily affects which of the following neurotransmitters?

Quizplus · Accepted Answer

11ec25c8_d0fe_a9df_bc81_d735d22926ef_MD0003_00 This patient's behavior is highly suggestive of obsessive-compulsive disorder (OCD). OCD is characterized by the presence of persistent intrusive thoughts/urges/images and/or compulsive acts performed in response to obsessions. Common themes involve fears of contamination, aggressive and sexual impulses, symmetry obsessions, and fears of harm. Images of horrific scenes (eg, running over a person) or violent urges (eg, to stab someone) can occur. Related compulsions include cleaning rituals, checking behaviors (eg, this patient checking underneath his car and then the news), and mental acts performed in response to the obsession (eg, counting, repeating words silently, praying). Patients with OCD often perform multiple time-consuming rituals and recognize the irrational nature of their behavior but feel unable to stop and are likely to suffer significant distress and functional impairment. Although multiple neurotransmitters and regulatory mechanisms are thought to contribute to the clinical expression of OCD, serotonin is the primary pharmacological target. First-line treatment is a selective serotonin reuptake inhibitor antidepressant (eg, fluoxetine, fluvoxamine, paroxetine, citalopram, escitalopram, sertraline). The serotonergic tricyclic antidepressant clomipramine is generally used second line because it is less well tolerated. (Choice A) Dopamine is the primary pharmacological target of antipsychotic medications used in the treatment of psychotic disorders. Antipsychotic monotherapy is not a first-line treatment for OCD. Antipsychotics may be used as adjunctive medications in patients with inadequate response to a serotonergic antidepressant. (Choice B) Gamma-aminobutyric acid is the major inhibitory neurotransmitter in the CNS and is the primary target of benzodiazepines. (Choice C) Glutamate is the major excitatory neurotransmitter in the CNS and is thought to play a role in many psychiatric disorders. However, the efficacy of medications targeting glutamate receptors in OCD has not been established. (Choice D) Norepinephrine is a catecholamine involved in mood, anxiety, alertness, learning, and memory. Although drugs that affect both serotonin and norepinephrine have been used in OCD (eg, serotonin-norepinephrine reuptake inhibitors), the role of serotonin is primary. Educational objective: Serotonergic antidepressants (eg, selective serotonin reuptake inhibitors) are the first-line medication treatment for obsessive-compulsive disorder. References: Obsessive-compulsive disorder. (http://www.ncbi.nlm.nih.gov/pubmed/24576790) Pharmacological treatment of obsessive-compulsive disorder. (http://www.ncbi.nlm.nih.gov/pubmed/25150568)

A 19-Year-Old Man Comes to the Office Due to Overwhelming