1. What are the main classes of antidepressants and how do they work? Provide an example of a drug for each class. Answer: The main classes of antidepressants are selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs), and atypical antidepressants. They work by increasing the availability of neurotransmitters such as serotonin, norepinephrine, and dopamine in the brain, which are involved in mood regulation. Examples of drugs for each class are fluoxetine (SSRI), venlafaxine (SNRI), amitriptyline (TCA), phenelzine (MAOI), and bupropion (atypical). 2. What are the common side effects and contraindications of antipsychotics? How can they be managed? Answer: The common side effects of antipsychotics include extrapyramidal symptoms (EPS), such as dystonia, akathisia, parkinsonism, and tardive dyskinesia; metabolic syndrome, such as weight gain, diabetes, and dyslipidemia; sedation, orthostatic hypotension, anticholinergic effects, such as dry mouth, blurred vision, constipation, and urinary retention; and neuroleptic malignant syndrome (NMS), which is a rare but life-threatening condition characterized by fever, muscle rigidity, altered mental status, and autonomic instability. The contraindications of antipsychotics include hypersensitivity to the drug, severe cardiovascular or cerebrovascular disease, blood dyscrasias, liver or kidney impairment, and history of seizures. The management of side effects and contraindications depends on the type and severity of the adverse reaction. Some general strategies are dose adjustment, switching to a different drug or class, adding an adjunctive medication, monitoring vital signs and laboratory tests, providing education and counseling, and implementing lifestyle modifications. 3. What are the indications and mechanisms of action of mood stabilizers? Name two examples of mood stabilizers and their therapeutic ranges. Answer: The indications of mood stabilizers are bipolar disorder, cyclothymia, schizoaffective disorder, and other conditions that involve mood swings or instability. The mechanisms of action of mood stabilizers are not fully understood, but they may involve modulating the activity of neurotransmitters, ion channels, second messengers, and gene expression in the brain. Two examples of mood stabilizers are lithium and valproic acid. The therapeutic range of lithium is 0.6 to 1.2 mEq/L and the therapeutic range of valproic acid is 50 to 125 mcg/mL. 4. What are the benefits and risks of benzodiazepines in the treatment of anxiety disorders? How can benzodiazepine dependence and withdrawal be prevented or treated?