Camilla Lyons, MD, MPH, a psychiatrist and member of the Alma mental health co-practice community, says that if you "develop new or worsened mental health symptoms," it's a definitive sign your antidepressant isn't working. This could occur for any number of reasons: For example, as Psychology Today reported, many people who have bipolar disorder are often misdiagnosed with depression, and, while Healthline says mental health professionals may choose to prescribe antidepressants to people with bipolar disorder, they can also have adverse side effects, like potentially triggering a manic episode.

"While some psychiatric medications are associated with rare but serious side effects, you should always consult with a physician before making any changes to your medications," Lyons says, adding that, "When in doubt, you can always visit your nearest emergency room in the event that you cannot reach your doctor."

From your quality of sleep, to what you dream about, antidepressants can impact many aspects of sleep. Goulston says that "persistent sleepiness or sluggishness that may cause you to drink excess caffeine to stay awake" is one indication your antidepressant isn't a good fit. Oppositely, he says that if your medication is causing "persistent insomnia," it may also be a sign your antidepressant isn't right for you.

It's important to keep in mind that, according to VeryWell, research has shown it can take anywhere from eight to 12 weeks to feel the full benefits of an antidepressant. In more severe cases, it could take up to six months. However, West explains, "Antidepressants may not be working if your mood remains depressed, [or] you find yourself not functioning at your usual level. These are changes you may personally notice yourself, or in some cases, you might not be as aware, but someone close to you who you spend time with might observe."

Antidepressants won't work overnight like magic. Yet, it's a good idea to try to schedule an appointment with your prescriber if you find your symptoms haven't began to improve as you near that eight-week mark.

When you first begin an antidepressant, the Mayo Clinic reports it's normal to experience side effects from the medication, with nausea, diarrhea, decreased libido, fatigue, dry mouth, weight changes, dizziness, irritability, and insomnia among the most common symptoms. Yet, Lyons says if these side effects become "intolerable," or don't seem to go away once you've been on a steady dosage of the antidepressant, it may be time to consult with your physician if you should make a medication switch. Though many medications have side effects, you may want to consider talking to your doctor if you feel they are interfering daily activities.

Goulston says that you may want to speak to your prescriber about switching your mental health medication if you find you're less depressed, but also less motivated. As Harvard Health reported in 2016, it's not uncommon for folks on psychiatric medications to experience a "blunting" effect that seems to almost dulls their emotions. In fact, a 2018 study found that antidepressants can induce apathy, indifference, and a lack of interest in some people within six weeks of starting a medication.

"If you are feeling 'back to yourself,' and those close to you agree, the treatment you are engaged in is likely working," says West. However, if your mental health issues still seem to be interfering in your daily activities, work, or relationships, you still might need to adjust your dosage or switch your psychiatric medication.

West says that, in some cases, your doctor may make other treatment recommendations if you don't have success with traditional mental health medications. "Research has found 5.5 million depression sufferers do not find relief from antidepressant medications, and that is when a specialist may be needed," he explains.

All-in-all, Goulston says being your own advocate and speaking up if you experience any of these signs is one of the most important things you can do throughout this process. Try not to feel discouraged if an antidepressant doesn't work for you — it's very typical to have to try multiple medications before finding one that's effective for you. With the help of your psychiatrist, you can get to a place where you feel confident about your mental health treatment.

If you or someone you know is seeking help for mental health concerns, visit the National Alliance on Mental Health (NAMI) website, or call 1-800-950-NAMI(6264). For confidential treatment referrals, visit the Substance Abuse and Mental Health Services Administration (SAMHSA) website, or call the National Helpline at 1-800-662-HELP(4357). In an emergency, contact the National Suicide Prevention Lifeline at 1-800-273-TALK(8255) or call 911.