Addiction -learned or acquired?

What causes addiction (in particular to substances)? That feeling of needing to escape from the reality? I’m sure part of it is something that comes from your past or growing up. I’m not sure how much influence genetics have. Or if it’s primarily upbringing and parenting? The reason why I’m asking is because I want to give my children a good life, raise them to be strong individuals and make smart decisions. I don’t want to see them struggle like some people in my family and my SO’s family. So much pressure and I don’t want to fuck it up.