Will childhood depression be caused by verbal abuse?

It certainly could: Contribute to it.

Verbal abuse impacts: On a child's self image and self esteem and ability to trust others. This impacts on how they develop relationships and how well they do in school. If verbal abuse is rampant at home the child may not want to have friends visit, so they may have less friends. Depression is one possible outcome, but other psychological disorders, anxiety, eating disorders or anorexia or others could develop.

Often is: As an autopsy pathologist, I've run into this too often. Society is finally waking up to the impact of bullying in school and on social media, and will perhaps eventually realize that verbal abuse by parents is far more common and devastating. In times like ours, liability fears drive treatment, the child ends up getting medicated and the real problem may never be addressable

Depression - trauma: If there is no evidence of a family hx of depression and you experienced prolonged and severe verbal abuse, it is possible to have developed a negative self-esteem from the abuse which can lead to pessimism about self, the world, and the future. As a result then depression can occur.