In my clinical experience, I have seen that depression is usually caused by a child born with a sensitive temperament who experiences
significant environmental stressors.
Not exact matches
An
environmental risk factor might be
significant family stress during the pregnancy, maybe she was laid off and there are some financial
stressors, maybe there was a great transition during her pregnancy like they moved, etc..
Moreover, causal situations may be different for different individuals - while one person may develop schizophrenia due to a strong family history of mental illness, someone else with much less genetic vulnerability may also develop the disease due to a
significant pre-natal or
environmental stressor during their lives.