Correct Answer: C

Rationale: Methylphenidate is a central nervous system stimulant often prescribed to manage symptoms of ADHD. It works by increasing the activity of certain neurotransmitters in the brain, helping to improve focus, attention, and impulse control in individuals with ADHD. Haloperidol, Sertraline, and Clozapine are not typically used as first-line treatments for ADHD. Haloperidol is an antipsychotic used in conditions like schizophrenia, Sertraline is an antidepressant primarily for mood disorders, and Clozapine is an atypical antipsychotic for treatment-resistant schizophrenia.

Correct Answer: C

Rationale: Methylphenidate is a central nervous system stimulant commonly used in the treatment of ADHD. It helps improve focus, attention, and impulse control in individuals with ADHD. Haloperidol and clozapine are antipsychotic medications typically used for other conditions such as schizophrenia, while fluoxetine is a selective serotonin reuptake inhibitor commonly used to treat depression and anxiety disorders. Therefore, the correct answer is Methylphenidate (Choice C).

Correct Answer: B

Rationale: Prazosin is a medication often prescribed to manage nightmares in patients with PTSD. It works by blocking the action of adrenaline on specific receptors, which helps in reducing the intensity and frequency of nightmares. While flashbacks, hypervigilance, and depression are also common symptoms of PTSD, prazosin is specifically indicated for nightmares associated with the disorder. Flashbacks are typically addressed through therapies like cognitive-behavioral therapy, hypervigilance may be managed through counseling and coping strategies, and depression may necessitate antidepressant medications or therapy tailored for depression.

Correct Answer: C

Rationale: Paroxetine is a selective serotonin reuptake inhibitor (SSRI) commonly prescribed for obsessive-compulsive disorder due to its efficacy in managing OCD symptoms. While different SSRIs may be used based on individual patient response and tolerability, Paroxetine stands out as a well-established option for treating OCD. Fluoxetine (Choice A) is another SSRI commonly used for OCD, but Paroxetine is more commonly associated with this indication. Citalopram (Choice B) and Escitalopram (Choice D) are also SSRIs but are not typically the first choice for treating OCD.

Correct Answer: B

Rationale: Flat affect and social withdrawal are characteristic of negative symptoms in schizophrenia. Negative symptoms involve disruptions to normal emotions and behaviors, such as reduced emotional expression (flat affect) and social withdrawal. These symptoms reflect a decrease or absence of normal functions. Positive symptoms, on the other hand, involve the presence of abnormal behaviors or experiences, such as hallucinations and delusions, which are added to a person's experiences. Cognitive symptoms relate to difficulties with thinking, memory, and processing information, impacting cognition. Mood symptoms involve disturbances in mood regulation, which is distinct from the flat affect seen in negative symptoms.