Alternatively, Dr Richard Wise, psychologist at Windana Drug and Alcohol Recovery, believes the relationship between work and drinking may be bi-directional.
Results from several longitudinal studies among adults suggest that the association between depression and headache may be bi-directional [9 11].
Previous researchers have hypothesized that the relation between migraine and psychiatric disorder may be bi-directional given that migraine patients have a more than threefold risk of developing depression and the presence of depression is also associated with a greater risk of developing a migraine [21, 24].
It is still under debate whether the pain might be considered the cause or the consequence of psychological symptoms[9], and results from longitudinal studies among adults suggest that the association between depression and migraine may be bi-directional[10 12] bi-directional[10 12]genetic factors[13].
Therefore it is possible that even within a single tissue there may be bi-directional regulation of certain pathways in different regions of the organ.
The true relationship may be bi-directional.
The relationship between smoking, alcohol use, physical inactivity and frailty may be bi-directional, in that frailty itself may result in avoidance of smoking, alcohol and physical inactivity.
It is worth mentioning that these associations may be bi-directional: while insight may influence therapeutic relationship, therapeutic relationship may also influence insight.
Therefore, the effect of DNA methylation on gene expression may be bi-directional, nonetheless, higher methylation tends to repress gene expression.
However, the flow may be bi-directional in the presence of another congenital cardiac abnormality, such as a bicuspid pulmonary valve [ 37].
