Sometimes we can figure out the best antidepressant to start by asking the right questions. Before I choose an antidepressant for my patient, I think about these 6 questions. We can frequently narrow down the choices so we know which antidepressant to try first.

If you are considering starting an antidepressant, make sure to read my last post on common side effects of antidepressants, how long the side effects will last, and tips for how to deal with side effects. My next post talks about what to expect for a treatment response from antidepressants (ie the important question of "When will I feel better?")

What is the best antidepressant?

I explain to people all the time that one antidepressant isn't necessarily "better" or more effective than another antidepressant. The best antidepressant is the one that will work for you!

But how do we figure that out?

Just because a new antidepressant has commercials full of happy people that say they have responded wonderfully to the medicine doesn't mean that it is better than a medicine that has been around for 20 years.

Unfortunately, we don't usually know for sure which medicine will be the best antidepressant for you. There isn't a blood test or brain scan that tells me a particular drug will work wonderfully for you.

Some people hope to get that information from genetic testing but genetic testing doesn't actually tell us which antidepressant you will respond to. Genetic testing tells us how efficiently you will process the medicine in your body but not what will work. I'm sure down the road genetic testing will be able to give us this information but, unfortunately, we are not at that point yet.

"Which antidepressant is right for me?"

Although we have no guarantees a particular medication will work, we are usually able to narrow the choices. We can better answer "Which antidepressant is right for me?" if we go through each of the following 6 questions.

These 6 questions to ask to get closer to your answer:

1. Have you taken an antidepressant in the past and done well?

I'm shocked by how often I see people who have a history of doing well on a medication but aren't restarted on that same medicine later when symptoms return.

I think sometimes people are started on new medications because:

1. A thorough medication history wasn't taken.
2. Someone (doctor or patient) falls for the promise of happiness shown in the commercials of new shiny medications.
3. The patient wants to take something that has free samples available.
4. Although the medication worked really well, the person had side effects. Hopefully, a different medication will work as well but without the same side effects (btw this would be a great reason for trying something new!).

Whatever the reason, if you have done well on a medication in the past there ought to be a very good justification as to why a different medication is being chosen!

2. Is there a family history of success on a particular medication?

Another important indication of the best antidepressant to choose is if there is a family history of success on an antidepressant. If your mom and sister both take a particular medication and have a good response, I can't see any reason not to start you on the same antidepressant. The genetics are similar your family and people often respond well to medications that others in their family use.

Know your families mental health history!

Sometimes it's hard to talk to family about their mental health history but it's important information to know. Ideally, before you go see a doctor for an assessment ask your family if anyone has any psychiatric history, has taken any psychiatric medications, and what their response was.

If it turns out someone in the family has done well on a medication for a similar condition this can save you a lot of time trying other medications that may not be effective.

3. Generic vs Brand name: 

Newer isn't always better and it's a heck of a lot more expensive! For the most part, people do fine on generic medication and I recommend using them. Most people do not notice any difference between them.

That being said, there is a certain amount of allowed variability in the amount of active ingredient in a generic medication as compared to brand. This can be significant for someone that is barely taking an effective dose to control their symptoms. If the generic has 5% lower levels of active ingredient someone may experience a return of symptoms. If the generic has 5% higher levels they may feel better. Or if someone is prone to side effects, the side effects may increase if the active ingredient is higher.

One reason to choose brand is for people with allergies to inactive ingredients (fillers) that the active medication is mixed with. Generic medications do not need to have the same inactive ingredients as the brand medications so these fillers will vary between different companies. Since a pharmacy may frequently switch the generic company they get a medication from (whoever is offering the best price wins) it can be hard to keep track of which generic is OK to take. For these people, taking brand name may be worth it.

4. What symptoms are we trying to treat?

Some antidepressants work better for certain symptoms. Do you have:

• Anxiety?
• Obsessive Compulsive Disorder?
• Depression?

Defining which symptoms predominate for you will help us with choosing an antidepressant to start. Some antidepressants are better for depression than for anxiety. If you are mainly anxious, I wouldn't put certain medications as first-line options unless there is a compelling reason (like a family history of response).

5. What side effects are we trying to avoid?

• Fearful of sexual side effects?
• Weight gain?
• Did you have a terrible experience with withdrawal side effects on a different antidepressant?

Which antidepressant we start may depend on the side effects we are trying to avoid.

For example, Wellbutrin/bupropion doesn't have the same risk of sexual side effects as other medications. When choosing an antidepressant for someone with depression who is worried about sexual side effects Wellbutrin may be a great medication to start first (as long as the person doesn't have a seizure disorder).

6. Are there any drug interactions?

Certain medications affect the clearance of other medications by either speeding clearance up or slowing it down. Let's use an example: medication A speeds up the clearance of medication B. If you have been successfully taking medication B and I give you medication A, the levels of medication B will go down. When medication B levels go down you may no longer be at an adequate dose to control your symptoms (because your body is clearing it quicker).

The reverse happens if a medication slows the clearance of another medication. With this, medication B now builds up in the body and the person is at higher risk for side effects. Increased levels can be dangerous with certain medications.

A "real life" example of this is with Prozac and Tamoxifen. Tamoxifen is a medication used for certain types of breast cancer. Tamoxifen reduces the risk of their breast cancer coming back. If Prozac (an antidepressant) is added to Tamoxifen it causes the body to clear Tamoxifen quicker. The levels of Tamoxifen will be reduced so the medication may be less effective at minimizing the risk of breast cancer recurrence. Obviously, drug interactions can have serious consequences and we have to use care when choosing an antidepressant that can have interactions.

Choosing an antidepressant: So which antidepressant is right for me?

Make sure to go through each of these 6 questions when trying to make the decision about which antidepressant to start. It may still end up being a frustrating process of trial and error, but we have more of a chance of getting it right the first time if we ask the right questions.

Don't forget: Depression and anxiety are treatable conditions! Antidepressants are only one part of the treatment equation. There are other great ways to help yourself feel better and sometimes doing a bit of all of these will get you better faster. Add in these other symptom management techniques that I review in the following posts:

• 11 Effective Interventions for Depression
• Treating Depression with Exercise
• 5 Ways to Stop a Panic Attack
• Do what you are afraid of: Stop letting anxiety control you

Visit the mental health bookstore for a list of books I recommend for anxiety and depression (and many other mental health topics).

A version of this article first appeared here.