15 yr old starting with depression . mom has severe health anxiety , paternal grandmother committed suicide , dad has some anxiety as well. is it a given that teenager will have life long mental health issues as a result ? just started prozac?

Depression can certainly be genetic & thus can be inherited & likely as a dominant feature so there is 50:50 chance of parent sufferring from depression can pass it to any one of their chidren. Inheritance of anxiety is another matter, living with someone with anxiety is sufficient to makw another anxious. Very important to self recognize depression and get help, can be dangerous not to get help.

Genetic proclivity can enhance susceptibility to an emotional disorder. Life-long mental illness is NOT a given, and an adolescent can learn compensatory measures, such as meditation, exercise, principles of cognitive-behavioral therapy, and hopefully avoid the use of antidepressant medications, as a lifestyle.