This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
Which of the following antismoking drugs can lead to suicidal ideation? 
Select and explain. 
A. Baclofen, B. Rimonobant, C. Varenicline, D. Naltrexone
C: Varenicline
Answer: C: Varenicline 
Explanation: Vareniciline is a partial agonist at α4 β2 substype of nicotine receptor used to treat tobbacco addiction.
Side effects include suicidal ideation, nausea, headache & insomnia.