Everyone does yoga for different reasons - exercise, flexibility, meditation, posture, community, etc. But yoga can also be useful for your mental health, especially if you've experienced trauma or have other mental health concerns.
Talk therapy is obviously a great option for treatment, which focuses on your thinking patterns and reactions to stress. However, we also hold a lot of stress in our bodies. Right now I want you to lower your shoulders. You probably didn't even realize that you were holding them tight close to your ears, which causes tension and even pain.
Trauma-informed yoga helps you notice what's going on in your body and learn how your brain and body works together. It helps you to identify triggers and figure out ways to cope with them, allowing you to calm yourself down before things get out of control.
As a great example of how you can use yoga and other body-focused activities to address mental health concerns such as anxiety or PTSD, Julie from Yoga for Healing recommends this self-holding exercise as something you can do at home.