Medication will not change who you are as a person. Antidepressants assist people in experiencing the full range of emotions without feeling overwhelmed. This may seem like a personality change, but it is more accurately a sign that you are recovering your ability to react to people and situations in a non-depressed way. My friend is being treated for depression, and her doctor did not suggest medication for her. Depression takes different forms in different people, so that two people who have depression can have completely different symptoms.
Antidepressant medication is for depression where specific types of symptoms are present.
Similarly, an antidepressant that helped a friend or family member may not work for you. Your doctor will continuously assess the effects of your treatment, but typically, people take antidepressants for 8 to 12 months or longer.