Shared characteristics in the clinical expression and pharmacological responses of mental disorders and their possible collective significance

An Emerging Natural History in the Development, Mechanisms and Worldwide Prevalence of Major Mental Disorders

Conciliating recent findings from molecular genetics, evolutionary biology, and clinical observations together point to new understandings regarding the mechanism, development and the persistent worldwide prevalence of major mental disorders (MMDs), which should be considered the result of an evolutionary downside trade off. Temperamental/trait variability, by facilitating choices for individual and group responses, confers robustness flexibility and resilience crucial to success of our species. Extreme temperamental variants, originating evolutionarily from the asocial aspect of human nature, also constitute the premorbid personality of the disorders. The latter create vulnerable individuals out of whom some will develop MMDs but at much higher rate to that of the general population. Significantly, similar temperamental "lopsidedness" enables many of these vulnerable individuals, if intelligent, tenacious, and curious, to be creative and contribute to our survival while some may also develop MMDs. All have a common neural-developmental origin and share characteristics in their clinical expression and pharmacological responses also expressed as mixed syndromes or alternating ones over time. Over-pruning of synaptic neurons may be considered the trigger of such occurrences or conversely, the failure to prevent them in spite of it. The symptoms of the major mental disorders are made up of antithetical substitutes as an expression of a disturbed over-all synchronizing property of brain function for all higher faculties previously unconsidered in their modeling. The concomitant presence of psychosis is a generic common occurrence.

Considering the major mental disorders as clinical expressions of periodic pathological oscillations of the overall operating mode of brain function

The consideration of the collective significance of the shared characteristics and overlaps in the clinical expression and pharmacological responses of the major mental disorders (namely, schizophrenia, bipolar disorders, obsessive compulsive disorder, anxieties/phobias, borderline syndrome and possibly others) supports the following: (1) These disorders have a common, initial neurodevelopmental origin. (2) They occur probabilistically on some of "at-risk" individuals whose pre-existing, extreme, temperamental/structural variance confers vulnerability for such occurrence. (3) Lastly, each of these syndromes can be considered as a clinical expression of oscillations (i.e., a switch to a pathologically ordered phase) of the overall, common operating mode of brain function. This mode based on a particular-for-our-brain, emergent quality of complexity, normally ensures the synchrony, coordination, subtlety and robust flexibility in the expression of the components of each of the various higher faculties of the brain, namely, the faculty of: (1) mood modulation; (2) coordination of feelings, thoughts and the responses to the external world; and (3) keeping constrain and limited but appropriate input of primitive drives. The conclusions in this paper have important ramifications in rethinking the current nosological procrustean flawed classification and the neurodevelopmental origin of the major mental disorders as well as the biases shown in selecting subjects for research. It also opens opportunities in the future development of novel, effective, economical and harmless therapies that will restore and maintain the normal phase of the operating mode of brain function. For example, the patient can wear an appropriate electronic device that sends a particular type of signal to the brain which will affect remission and prevent relapses without harm. We can thus avoid the use of pharmacological agents which have limited effectiveness, severe, long-term side-effects and financial burden to the patient.