People spend most of their day time at work and most of their time working for their Boss. On average, people spend between 7 and 9 hours a day working, during working days (from an office or remotely).
And it's not bad to think that whatever happens at work will have an impact on a person's mental health, well-being and wellness. That means they can be positive or negative impact from ones working place.
And since people work with teams and bosses, it's also evident that the "boss" can have both a positive or negative impact on the people they lead.
And it is very possible to conclude that those that lead people can impact on the mental health of the people they are leading more than doctors or therapists and as much as their spouses or partners. It's shocking, but not surprising, that the adage "people don't leave companies, they leave bad bosses" is actually true.
A leader, impact on people's mental health like this: a boss can break you, or  lift you up. A boss can destroy your mental health, or care for it . A boss can destroy your experience at work or make your experience remarkable.
A bad boss is someone whom you will not like to work with and also want to forget as soon as you can, while a good boss is someone you will never forget and someone you will always like to work with forever if possible.
I have worked with a good bosses and I will like to share some of my experience with my boss
My boss cares for me as a human, not just as a worker. His behavior towards me shows that he cares in every possible way, not only about productivity and performance. I remember coming to the office one day and I developed feverish condition which my boss noticed and asked Me to go and get medicine which he paid for it and gave me a leave from work without cutting off my salary.
My boss has a positive influence and impact on me that extends way far beyond my working experience with him. That influence has stayed with me for a very long time, even till now.
I still remember the most amazing things my boss did for me, I started working with him as an undergraduate, he made sure I further my education and he paid my tuition fee for my first year as an encouragement for me to further my education even though I was not his relative. My boss believed in me and that  championed my growth and development, how he guided me and helped me added to my growth.
The little part of my best exists today because my  boss believed in me, supported and encouraged me.
My Boss makes me feel safe at work and that helps my mental health to be stable.
My boss shows appreciation, gratitude and recognition for the efforts and results I put towards work and it's progress.
My boss gives me credit when credit is due, and provides meaningful and kind feedback when necessary.
My boss knows that am not (just) an employee, but a human, and treats me accordingly.
In conclusion a good boss can create long lasting impact that becomes their legacy and you will want to always treasure in your heart and mind.