The past three months and is not relieved by sleep

A 25-year-old woman presents to her primary care physician because she has been feeling fatigued. She states the fatigue has been getting progressively worse for the past three months and is not relieved by sleep, although she has been averaging 12-16 hours of sleep per night. She also complains of difficulty concentrating at work, poor appetite, a 4.5-kg (10-lb) weight loss, and reduced interest in socializing with her friends. Physical examination is normal. Laboratory tests reveal a negative Monospot test, normal liver function, and normal thyroid function. Serum iron, ferritin, total ironbinding capacity, vitamin B12, and folate are all within normal limits. The patient is diagnosed with a major depressive episode and given a prescription for an antidepressant. Nortriptyline acts by which of the following mechanisms?

(A) Depleting the adrenergic nerve terminal of norepinephrine
(B) Inhibiting serotonin reuptake and acting as a partial serotonin agonist
© Inhibiting the presynaptic enzyme responsible for the breakdown of dopamine, norepinephrine, and serotonin
(D) Inhibiting the reuptake mechanism responsible for terminating the action of both norepinephrine and serotonin
(E) Inhibiting the reuptake mechanism responsible for terminating the action of serotonin only

Ans:(D) Inhibiting the reuptake mechanism responsible for terminating the action of both norepinephrine and serotonin