You could maybe check out the book "Feelings Buried Alive Never Die" by Karol K. Truman. It has a section where she talks about what we experience in the womb and our childhood, can affect us for the rest of our lives. (Like if our mother was under alot of stress or had a bad relationship with our father ect. Also, I believe that there is something on this site that talks about that...how we not only deal with what is going on in OUR life, but we also deal with (on a subconscience level) what our ancestors have dealt with and maybe never resoloved.) Anything traumatic ect. has "energy", until it is resoloved.
So, to answer your question, YES, I believe that it is genetic to a certain extent. But don't forget that WE can change our genetics...anytime you better yourself physically, mentally ect. you are actually changing your genetics, and that will be passed to your children. Example: If you cleanse, eat healthy, choose to think healthy and postitive, those strengths will go into your genes. Thats why you do have certain strengths and "weaknesses" within family lineages.
Have you done any cleanses? If you haven't, I would look into them. Just about anything you would want to know about is on Curezone!!! I also, know that certain essential oils are very mentally uplifting, like frankinscense sandalwood,
lavender, orange ect.
Do you take cod liver oil, wheat germ oil and flax oil?? I can't remember which one it is, but one of them corrects the "imbalance" in the brain that causes depression. You might want to look into that too.
Just some thoughts. Hope this helps.