There are multiple factors that affect mental health.
Every person's journey with their mental and emotional well-being is different so i believe it's tough to generalise any number of factors that can lead to mental health issues.
Some may be more affected by loss, some may be affected by overbearing attention.
The only thing is that we must be understanding of each others' issues. We must becareful not to bring toxic positivity into anyone's life nor infuse negativity into difficult spaces.
The way we talk to children, answer their questions and talk to each other when children are around impacts them the most. Kids notice and copy our words, actions and behaviour.