ABSTRACT
Recently, conciliating findings from molecular genetics, evolutionary biology, along with empirical clinical evidence regarding the major mental disorders (MMDs) namely bipolar affective disorder (BPAD), schizophrenia, obsessive compulsive disorder (OCD), the anxieties with depression, autism and attention deficit/hyperactivity disorder (ADHD) all point to a common neural-developmental origin. Genetic loci associated with schizophrenia do not directly lead to the disorder; instead, they code for the expression of lopsided, temperamental, variants in individuals that originate mainly from one part of our human nature which applies also, to the rest of the MMDs. These individuals contribute to the flexibility, robustness, and creative input of our species, concomitantly, they incur vulnerability to the development of a MMD as an evolutionary trade off. MMDs initially, are expressed as periodic epiphenomena on the underlying temperamental extreme variants of brain function. Their expressions tend to become permanent. Underlying, aberrant traits remain unaltered. Their clinical expressions are characterized by “either-or”, antithetical substitutes, in addition to co-occurring psychosis. The latter is a common occurrence to other assaults on brain function. Characteristic, “ether-or” symptoms are the result of a disturbed, overall, coordinating property of brain function, normally responsive to the smooth, synchronizing expression of all higher mental faculties. Clinical findings point to the need of modifying the current schema in order to better reflect their collective significance in order to help guide research to a new, more promising direction in elucidating their triggers, development, and mechanisms whereby opening a new horizon for therapy and treatment.