TOXINFECTIOUS PSYCHOSES. — Mental syndromes that arise in the course of general diseases and infectious diseases not particularly localized in the nervous system, attributable to the action of autotoxins (renal insufficiency, hepatic insufficiency, deficiency states, endocrinopathies, etc.) and bacterial toxins (febrile diseases in general).
Thus delimited, the t. p. correspond to Bonhoeffer’s “symptomatic psychoses” and do not include the “toxiphrenias,” or psychoses caused by exogenous intoxications (alcohol, narcotics, occupational intoxications: phosphorus, lead, etc.), which resemble them in certain pathogenetic and clinical aspects. Symptomatic psychoses and toxiphrenias have a common causal basis (toxic etiology in the broad sense) extrinsic to the individual constitution; hence the designation exogenous psychoses (or acquired psychoses, according to Bleuler), to distinguish them from endogenous psychoses (that is, those intimately linked to constitutional factors). Yet in the morbid picture produced by a toxin, the undeniable, though variously evaluated, influence of endogenous factors can always be discerned, and for this reason not all authors agree in accepting such a definition. This interference is inferred from the small number of cases in which a symptomatic psychosis occurs, compared with the high percentage in which the general disease that produced it occurs; furthermore, from the diversity of the psychic pictures that the same cause may produce and from the variety of morbid agents that may trigger the same psychic syndrome. In other words, a given traumatic, toxic, or infectious cause, under equal conditions (that is, intensity, duration, etc.), produces a psychosis only in certain individuals (who therefore appear constitutionally predisposed), and the symptoms displayed by one individual may differ greatly from those displayed by another, while the same symptoms may occur as a result of entirely distinct morbid causes: this would signify that the development and clinical manifestations of a symptomatic psychosis are extensively conditioned by individual factors (constitutional predisposition). Thus, a slight elevation of temperature triggers violent delirium in some, whereas many tolerate high temperatures without displaying any symptoms; acute alcoholic intoxication (drunkenness) may manifest itself in very different ways (euphoria, depression, excitement, torpor), while alcoholic delirium, uremic delirium, and a typical delirium may sometimes be indistinguishable. The influence of a constitutional predisposition is even more evident from the observation, in some individuals, of the same psychic picture recurring several times during their lives as a result of different morbid agents. At times, a familial “reactive” predisposition can be recognized, in the sense that the onset of symptomatic psychoses is observed in several members of a family; these psychoses may also assume a similar appearance.
The role of endogenous and exogenous factors has given rise to the most diverse interpretations and classifications of t. p. and constitutes one of the central problems of psychiatry. Some authors admit an acquired predisposition arising during life as a result of previous diseases that would have prepared the ground for the symptomatic psychosis, but this is not admissible in all cases.
Bonhoeffer explains the lack of a relationship between cause and effect (that is, between the morbid agent and the symptom) through his “theory of the exogenous reaction”; intoxications or infections would give rise to metabolic toxins (Kraepelin’s “metatoxin”) not specific to the initial morbid episode, toxins that would represent the direct causes of the “syndromes,” or elective types, of the exogenous reaction. The psychic pictures thus designated are therefore not pathognomonic of any particular morbid form, but are common to the entire group of exogenous psychoses and very different from those observed in endogenous psychoses (that is, those linked to constitutional factors). According to Bonhoeffer, the elective types of exogenous reaction are: clouding of consciousness, acute delirium, amentia, hallucinosis, amnesic twilight states, etc. According to others, however, the influence of endogenous factors on the development and clinical manifestations of symptomatic psychoses is sufficiently important to invalidate the classification of psychoses according to exogenous and endogenous causes, and some (Kleist) propose a classification according to the type of symptoms.
Stertz attempted to resolve the problem by proposing a classification based simultaneously on causal and symptomatic elements; in the psychic symptomatology produced by exogenous causes, he recognizes fundamental (or obligatory) symptoms and accessory (or optional) symptoms. While the former would be directly caused by the morbid agent, the latter would derive from a pathological constitutional predisposition made manifest by the action of the morbid agent. It should be noted that Stertz’s fundamental or obligatory symptoms are the same as those Bonhoeffer describes as elective in the exogenous reaction and which, according to Kleist’s “symptomatic” classification, would be “heteronymous” symptoms. Stertz’s optional symptoms, on the other hand, are those that characterize endogenous psychoses and which, according to Kleist’s symptomatic classification, would be “homonymous” symptoms.
The most frequent and important symptoms of t. p. are disturbance of consciousness, delirium, and psychomotor alteration. These symptoms may appear in various degrees and combinations, thus giving rise to the various syndromes (stuporous, delirious, amential, etc.) described by authors as typical of these disorders. Disturbance of consciousness is usually the cardinal symptom: the patient appears “confused,” lacking attentional concentration and the capacity for criticism, and completely disoriented; associations are slowed and incorrect, and delusional convictions are formed, nourished by illusions and hallucinations. Delirium is fragmentary and variable, usually terrifying in content (frightening visions, bestial screams, etc.), and produces a profound alteration of psychomotor mechanisms, which may manifest itself as an increase in motor drive, extending to extremely violent agitation, or as a slowing down progressing to complete arrest. These are the symptoms that predominate in the syndromes described as “elective of the exogenous reaction” by Bonhoeffer.
The prognosis is usually linked to that of the general disease, and in the majority of cases the disappearance of the psychic symptomatology follows the recovery from that disease. Sometimes, however, psychopathic forms (post-psychotic states) of greater or lesser duration remain. Treatment must be directed essentially against the general disease.