The most recent research evidence suggests that the relationship between the brain (structure, function, neurotransmitters) and psychosocial factors (socialization, rearing, life events) is best described as

A. far too complex to ever understand how one system influences the other.
B. an interaction where the brain affects psychosocial factors and vice versa.
C. a system where behavior and psychosocial factors impact the brain but not the other way around.
D. a system where the brain directly influences behavior and psychosocial factors but not the other way around.

There is a bi-directional relationship between the brain and the psycho-social factors. The effect of anxiety, depression, and stress on immune system responses in both animals and humans. It has been observed that depression and stress are associated with a rise in the level of circulating pro-inflammatory cytokines. Brain injuries play an important role in giving rise to psycho-social factors for eg. trauma.