13. "You can choose to be happy!"
Many people who do not have depression or a history of mental illness believe that happiness is a choice, and anyone not making that choice simply has to will themselves out of their sadness. Of course, this may work for many people who do not have depression, and their intention is simply to share the advice that has worked for them in the past; however, this approach is unlikely to be effective for those with the condition, so it is important not to expect it to be a viable approach.
Telling someone with depression that they can choose to be happy often feels like a slap in the face, as they have spent years of their lives trying to be happy.
Alternative: Instead of telling someone that they can choose to be happy, acknowledge that that might not be the case for them. Recognize that they may feel absolutely powerless in their condition, but suggest actual ways for them to regain control, such as seeing a therapist, psychiatrist, or beginning medication.