Top down central nervous system (CNS) influences
on the immune system and bottom up immune system in
fluences on the CNS take part in a complex feedforward
and feedback loop which may be responsible for initiating
events and perpetuating circumstances in the course of
neuropsychiatric as well as immune system diseases. In
this paper the authors examine the neuroendocrine
neuroimmune stress response system, the concept of au
toimmunoregulation, and recent studies of immune and
pharmacological dysregulation in neuropsychiatric and
psychosomatic illnesses. The authors review the recent
English-language literature on these subjects. Support
for the hypothesis that macrophages play an important role
in neurodevelopment and in the pathophysiology of vari
ous neuropsychiatric conditions is found. The interplay
between neurologic and immune systems may help to un
cover the pathophysiologies of certain neuropsychiatric
systems. This may provide new strategies for pharmaco
logic anti-inflammatory treatments. The monocyte/
macrophage, which crosses the blood-brain barrier is an
essential candidate cell in the study of psychoneuroim
munology.