It can be a very difficult situation to watch a loved one go through mental health issues. I've watched family members go through it, and friends and it is overwhelming. Although, each of their issues can be different, in no way should you ignore it.
Here are a few ways to help a loved one cope with mental health by American Psychiatric Association:
Know the warning signs - For example, withdrawal from social interaction, unusual problems functioning at school, work, or social activities, or dramatic changes in sleep and appetite are possible signs.
Confront the issue head-on - (keep it confidential) One of the hardest and most important steps may be just starting the conversation. You do not have to be an expert or to have the answers. Express your concern and willingness to listen and be there for the person. Don't be afraid to talk about it. Reassure them that you care about them and are there for them.
Educate yourself - The more you understand about conditions, symptoms, possible treatments, and what to expect, the better you will be able to support your loved one.
Seek solutions to the barriers - For example, make it easier for the individual by researching potential therapists, hours, locations, and insurance-related issues. If you think they might be barriers, address possible issues with transportation, childcare, strategies for communicating with an employer, etc.
Take care of yourself - (it can be overwhelming) While you're focusing on helping your loved one, it's also important to take care of yourself – physically and emotionally. Reach out for help for yourself if you need it. Recognize and acknowledge the limits of what you can give.
Have realistic expectations - It is important to have realistic expectations. Recovery is generally not a straightforward process, there will likely be improvements and setbacks along the way. With the permission of your family member, you can work with their treatment team to help provide support.
Research & Resources - Find out local resources, books, organizations, and communities.