Psychiatry - O. K. Napryeyenko 2001

Propaedeutics of Psychiatry
General Information on the Etiology and Pathogenesis of Mental Disorders

From the perspective of practical utility, mental illnesses are classified according to their origin into exogenous and endogenous. Exogenous disorders result from the pathological impact of various external (relative to Brain tissue) physical, chemical, and psychotraumatic factors on brain activity. These include harmful infectious-allergic, metabolic, intoxication, thermal, mechanical cerebrotraumatic, radiation, and other Physical and Chemical influences, as well as those caused by unfavorable social circumstances, particularly those triggering intrapsychic conflicts. Most researchers categorize psychotraumatic mental disorders into a third independent group known as "psychogenias".

While the primary causes of exogenous disorders are well understood, the Etiology of endogenous mental illnesses (such as Schizophrenia, manic-depressive or bipolar psychosis, so-called idiopathic or genuine Epilepsy, and certain late-life psychoses) remains largely unresolved. These diseases develop under METABOLISM/18.html">The Influence of hereditary, constitutional, age-related, and other bodily characteristics that dictate specific biochemical, immune, and other alterations, ultimately leading to primary pathological disorders of mental activity. According to the generally accepted view, external factors can only influence the onset and subsequent course of endogenous diseases rather than serve as their ROOT cause.

However, some authors consider it inappropriate to single out a distinct group of endogenous mental disorders, as they link The Emergence of these conditions to the consequences of exogenous influences embedded in the genetic matrix for future generations. In other words, the aforementioned diseases in a specific patient are caused by certain exogenous (or environmental) influences on their close or distant relatives, which were inherited by the patient.

Thus, The Theory of the etiology of mental illness is still far from perfect. Furthermore, as with the rest of pathology, the cause-and-effect relationships of the many factors influencing mental activity remain the least understood.

An encounter with any potentially pathogenic agent does not mean the fatal inevitability of mental illness. Whether a disorder develops depends on a combination of various factors, which can be categorized as follows: constitutional-typological (genetic and innate qualities, features, morphological and functional constitution, individual characteristics of biochemical, immune, autonomic, and other processes); somatic (acquired features of metabolic processes determined by the state of Internal Organs and systems, and ecology); and psychosocial (the specific nature of interpersonal relationships of the patient within their micro- and macro-environment, including occupational and familial ties).

By analyzing the interplay between constitutional-typological, somatogenic, and psychosocial factors in each specific case, one can better understand why, for example, during a flu epidemic, one patient's mental reaction is limited to an adequate individual response within the limits of mental reserves, another experiences a short-term pathological mental reaction, a third develops a persistent neurosis-like or neurotic state, or manifests an overt mental disorder. Consequently, methodologically, the onset of a mental illness cannot be strictly attributed to any single factor, no matter how powerful. It is more accurate to speak of the interaction between a specific factor and an individual's mechanisms of biological, psychological, and social adaptation. Therefore, mental illness is the result of an individual's inadequate integrated adjustment to biopsychosocial influences. At the same time, every mental illness has a primary cause without which the disease cannot develop; for instance, post-traumatic encephalopathy will not occur without a traumatic brain injury.

It is important to note the high significance of all three aforementioned groups of factors leading to mental disorders, while emphasizing that none of them individually possesses absolute pathogenicity. For example, while highlighting the substantial role of heredity in The Development of conditions like schizophrenia and manic-depressive psychosis, one must remember that even if one identical twin has either condition, the risk for the other twin is quite high, yet it does not reach 100%. Therefore, we should speak of heredity not in terms of endogenous mental pathology, but rather of a predisposition to it. The same applies to the influence of innate personality traits, morphological constitution, typical vegetative features, and so forth.

The realization of a hereditary predisposition is heavily influenced by additional detrimental factors. Most researchers point out that the onset of schizophrenia and its relapses are triggered in nearly two thirds of cases by psychological or physical trauma, somatic illness, intoxication, and the like. Psychogenias (neuroses, reactive psychoses), alcohol delirium, and other states of altered consciousness most frequently arise against the backdrop of somatic health issues.

THE ORIGIN OF certain mental illnesses is directly age-related. For instance, oligophrenia is caused by intellectual disability that develops in early childhood or results from congenital underdevelopment of the brain. Pyknoleptic seizures in children cease around Puberty. Presenile and senile psychoses emerge in later life. During critical age periods (puberty and Climacteric), mental disorders such as neuroses and psychopathologies are more likely to debut or become decompensated.

Gender also plays a certain role. For example, affective mental disorders occur more frequently in women than in men. Women show a higher prevalence of conditions such as Pica, Alzheimer's disease, involutional, hypertensive, and climacteric psychoses. Naturally, they also experience mental disorders resulting from hormonal and other shifts during Pregnancy or childbirth. Conversely, men predominate among those suffering from atherosclerotic, intoxicative, and syphilitic psychoses, alcoholism and alcohol-related psychoses, as well as neuropsychiatric disorders caused by TRAUMATIC BRAIN INJURIES.

A whole range of psychosocial and exogenous factors leading to mental abnormalities are directly related to the patient's professional activity. These occupational hazards include mental and physical overload, emotional strain, intoxication, hypothermia and overheating, high vibration levels, radiation pollution, noise, Hypoxia, hypodynamia, and Various Forms of deprivation. Each of these adverse influences has rather typical psychopathological consequences. For example, psychosocial situations accompanied by excessive mental stress more frequently lead to neurotic disorders, whereas pronounced deficits in sensory and Other types of stimulation predominantly cause psychotic-spectrum abnormalities.

It is also worth noting seasonal fluctuations in mental activity. Certain psychopathological conditions, particularly endogenous psychoses with a phasic course, exhibit exacerbations during the autumn and spring periods. Furthermore, the adverse impact of intense meteorological shifts should be noted, as patients with vascular, cerebrotraumatic, and other organic brain disorders are highly sensitive to them.

Situations leading to so-called deschronuroses have a negative impact on the neuropsychiatric state. This refers to disruptions in biological rhythms—such as daytime wakefulness and nighttime Sleep, a mismatch between mental and physical workloads and the individual's character type ("night owl" vs. "early bird"), artificially induced Menstrual cycle irregularities, etc.

Pathogenesis (The Mechanism of disease development) of mental illnesses is determined by the interaction, during the prenatal and postnatal periods, between the genetically determined factors of the individual's Organism and adverse psychosocial, physical, and chemical influences on their personality, brain, and extracerebral somatic sphere. Biochemical, electrophysiological, immune, morphological, systemic, and personal changes arising from this interaction—which can be investigated using modern Methods—are accompanied by characteristic pathophysiological disorders. In turn, these changes obey specific spatiotemporal patterns, ultimately determining the stereotyped nature of pathological neuropsychiatric manifestations, their dynamics, and Specificity.

Thus, pathogenesis, and consequently the form of a mental disorder, are determined by specific individual reactions to a multitude of exogenous and endogenous situations formed in The process of ontogeny and phylogeny. It must be emphasized that the neuropsychiatric sphere of each specific person responds to diverse pathogenic influences with an individual-specific limitation and a stereotyped complex of reactions.

At the same time, the same harmful influence in different people, depending on the body's individual compensatory capabilities and A number of other circumstances, can trigger diverse psychopathological complexes. For instance, alcohol abuse is accompanied by psychotic states that differ noticeably from one another. Worth mentioning here are alcohol delirium, acute and chronic alcohol hallucinosis, acute and chronic alcohol paranoid, Korsakoff's polyneuropathic psychosis, alcohol pseudoparalysis, and Wernicke-Korsakoff encephalopathy. Similarly, a single infectious disease may lead to febrile delirium, ammentia, epileptiform syndrome, symptomatic mania, and, at later stages, Korsakoff's Amnestic Syndrome, post-infectious encephalopathy, etc.

Examples of monoetiological monopathogenetic diseases should also be cited. Thus, genetically determined Metabolic Disorders play a leading role in the origin of Phenylpyruvic Oligophrenia. As a second example, cytological studies have revealed a specific chromosomal abnormality underlying the pathogenesis of Down syndrome.

At the same time, different etiological factors can "trigger" identical pathogenetic mechanisms that form the exact same psychopathological syndrome. As previously mentioned, a delirious state occurs, for example, in patients with alcoholism and during febrile infectious illnesses. It is also observed following traumatic brain injury, intoxication with various substances, and in somatic diseases (somatogenic psychosis). A convincing illustration of such psychopathological states arising from different causes is epilepsy, which belongs to polyetiological monopathogenetic diseases.

However, the stability of individual psychopathological reactivity is relative. The Qualitative and quantitative characteristics of pathological symptoms depend on many circumstances, particularly a person's age. For instance, in children—due to the morphological immaturity of the Central Nervous system and the resulting inadequacy of Abstract-logical, cognitive processes—ideational, primarily delusional, abnormalities are atypical. For this reason, pathological psychomotor phenomena (convulsions, agitation, stupor) as well as emotional ones (emotional lability, excessive fragility, fear, aggression) are observed quite frequently in them. As the child transitions into adolescence, youth, and adult developmental periods, elements of delusion may first appear, followed by delusional disorders, and finally—persistent delusional states.

The Study of the etiology of a mental disorder in each case is a mandatory prerequisite for the rational formulation of so-called etiological therapy, the goal of which is the sanitization of the patient's external and internal environment. Uncovering pathogenesis facilitates the Selection of the strategy, tactics, and methods of pathogenetic Treatment aimed at disrupting the internal pathological links that determine individual symptoms and syndromokinesis.

Knowledge of the etiological factors and pathogenetic mechanisms of a mental illness, alongside the analysis of clinical psychopathological and somatoneurological signs, forms the basis for the Classification of the disorder and, consequently, for prognosis and addressing the social objectives of psychiatric care.

Review Questions

1. Define THE CONCEPT OF "endogenous mental disorders" and provide examples.

2. Characterize exogenous Mental Illnesses and provide examples.

3. What are psychotraumatic mental disorders?

4. The Role of constitutional-typological, somatogenic, and psychosocial factors in the onset of mental disorders.

5. MODERN CONCEPTS OF the pathogenetic mechanisms of mental disorders.