Answer:
Studies show that mood disorders have a strong genetic and biological basis
Explanation:
Depressive disorder refers to a state where a person exaggerates the feeling of sadness and it affects his or her daily functioning. There are various causes for the disorder which include altered neurotransmitter or neuroendocrine functions, psychological or biological problems, etc.
In the above case, X'zavia is worried that her depressive disorder would not pass to her children as researches show as it has a strong genetic basis.