Mind-Brain Dynamics in the Pathophysiology of Psychiatric Disorders

Abstract

Short of a comprehensive understanding of psychiatric disorders, two parallel but phenomenologically different schools of thinking continue to guide treatment: the psychological school and the biological school. Yet both of these schools of thinking have major shortcomings. The psychological school does not explain how psychopathology is related to neuropathology, and the biological school does not explain how neuropathology is related to psychopathology. However, a new hypothesis contends that the mind and the brain influence each other. "Mind" in this sense does not refer to a psychic manifestation of complex neurological activity but rather an independent entity that has the ability to think, emote, and access memory either in connection with neurological activity or independent of it. An important consequence of this is that mental stress could hyperactivate the brain, and hyperactivity in the brain could cause mental stress, thus creating a vicious cycle of mutual overstimulation between the mind and the brain. According to the multi-circuit neuronal hyperexcitability (MCNH) hypothesis of psychiatric disorders, psychiatric symptoms develop when normal thoughts and emotions become abnormally amplified, prolonged, or distorted by pathological hyperactivity in the related circuits in the brain. Although this pathological hyperactivity can sometimes be initiated by the brain alone, it is almost always initiated by a superimposition of mental and emotional stress upon an underlying hyperexcitability of the neurological system. This article will discuss how the interactions between the mind and the brain influence: 1) the development of psychiatric symptoms; 2) the nature of the psychiatric symptoms; and 3) the severity of the psychiatric symptoms. It will also discuss the possible means by which the cognitive-emotional system interacts with the neurological system and speculate about where, based on brain architecture and detailed clinical observations, that interaction occurs. Acquiring a better understanding of mind-brain dynamics could help solve the mystery of mental illness and allow clinicians to treat mental and neuropsychiatric disorders with greater precision and with greater success.