[Experience of a research Ethics Committee and the challenges of the new Chilean legislation on research in human beings]. / Experiencia del Comité de Ética de Investigación en Seres Humanos de la Facultad de Medicina de la Universidad de Chile y los desafíos que impone la nueva legislación chilena en la investigación médica.

The welfare of research participants must be guaranteed by international ethical standards. This article communicates the procedures of the Research Ethics Committee of the School of Medicine, University of Chile (CEISH). The new Chilean legislation on research in human beings is also discussed. Law 20.120: "On scientific research in human beings, its genome and forbidding human cloning" establishes the ethical principles that must be accomplished in every research involving human beings. Article 28 of the Law 20.584 "Regulation of the rights and duties of health care users", forbids the participation of handicapped people who cannot express their will in scientific research. Article 13 states that people not related directly with patient care cannot have access to his clinical records (with the exception of people with notarial authorization by the patient). CEISH proposes that, in case of people with intellectual deficiency, the decision to approve a scientific research should be analyzed on an individual basis. If the person is capable of expressing his or her will or has stated his or her consent beforehand, the research can be authorized. If the person cannot express his or her will, the scientific research cannot take place. In prospective studies, a consent from the patient and an authorization of the health authority should be required to access clinical records. In retrospective studies, consent should be obtained from the patient when personal information is going to be used. If the information is nameless, the consent can be disregarded.

Avances en la clínica de las adicciones: el rol del aprendizaje y la dopamina / Update in the clinic of addictions: learning and dopamine

There are two parallel explanatory models for addictions. One is the homeostatic model, that explains tolerance and the abstinence syndrome. Tolerance and abstinence are reversible phenomena that mask sensitization. These appear more commonly with the continued use of drugs, and are based in the up-regulation of cyclic AMP. The other is the plasticity model, that explains sensitization and compulsive use of drugs or addiction. Addiction is probably irreversible, underlies tolerance, appears more frequently with intermittent use of drugs, and is based in learning and memory mechanisms. Both are boldly linked to environmental and behavioral elements. In the plasticity model, dopamine (DA) has an outstanding role. Its phasic discharge is a temporal reward prediction error marker. It is the prediction error that generates learning. All the addictive drugs provoke a very strong increase of phasic DA discharge in some cerebral nuclei by direct or indirect paths. This increase is interpreted by cerebral circuits as prediction errors that generate learning behaviors. Pavlovian and operating type learning is involved. It is clinically observed as the prominence of environmental cues that are related to drug consumption, and the appearance of behaviors directed to the search and use of drugs, that are mainly involuntary and triggered by these cues. Pleasure (primary reinforcement) plays a role in this model, only in the initial stages of addiction. Understanding this double parallel model allows to design therapeutic interventions directed towards a conscious control of involuntary, environmental and affective cues that trigger drug search and use.

Modelos neurocognitivos en la esquizofrenia: rol del córtex prefrontal / Neurocognitive models of schizophrenia: the prefrontal cortex role

Los modelos neurocognitivos han dado lugar a un importante avance en la comprensión de diversos desórdenes mentales tales como la esquizofrenia (EQZ). En ese contexto, la disfunción del córtex prefrontal (CPF) es un hallazgo central para explicar su sintomatología. Se ha observado que los niveles anormales de activación de la CPF, así como disfunciones en la conectividad con otras estructuras cerebrales, juegan un importante rol en la delimitación de la enfermedad. Material y Métodos: A través de una revisión teórica, empírica y clínica se describirán cinco aproximaciones neurocognitivas de la esquizofrenia. Conclusiones: Aunque la etiología de la EQZ es probablemente múltiple, un desorden de la interconectividad neuronal, y especialmente de la CPF explican un amplio espectro de su sintomatología.

Introduction: Neurocognitive models gave place to an important improvement in our understanding of several mental disorders such as schizophrenia. In this context, Prefrontal cortex (PFC) dysfunction is an essential variable for its symptomatology account. It has been observed that abnormal level of PFC activation, as well as connectivity dysfunctions with other cerebral structures, play a central role in the delimitation of the disease. Materials and Methods: Through a theoretical, empirical, and clinical review, five neurocognitive approach of schizophrenia will be described. Conclusion: Although schizophrenia etiology is probably multiple, neural interconnectivity disorders and specially those related to PFC, explain a broad range of its symptoms.

Trastornos de ansiedad en pacientes hospitalizados en Medicina Interna / Anxiety disorders among patients hospitalized in a medical ward

Background: Anxiety symptoms and anxiety disorders are common among medical patients, however few studies differentiate both and consider the psychiatric comorbidity of anxiety disorders among such patients. Aim: To evaluate the presence of anxiety disorders among patients admitted to a medical ward. Patients and methods: Random selection of 406 patients (mean age 56 years, 203 female), hospitalized in a medical ward of a public hospital, mainly for cardiovascular, genitourinary and digestive diseases. All were assessed using an structured interview for DSM-III-R. Results: Twenty six percent of women and 13% of men had anxiety disorders. Fifteen percent of women and 6% of men had specific phobias, 7% of women and 4% of men had generalized anxiety, 5% of women and 0.5% of men had agoraphobia, 3% of women and 0.5% of men had social phobia, 1% of men and 0.5% of women had panic disorders and 0.5% of women had a post traumatic stress. Specific phobias and social phobias started during childhood. Anxiety and agoraphobia started during adulthood. Among patients with anxiety disorders, 43% of women and 34% of men did not have other psychiatric ailment, 34% of women and 19% of men had an associated depression and 34% of men had disorders due to use of alcohol. Conclusions: A high proportion of patients hospitalized in medical wards have anxiety disorders, that once identified it may help to treat the medical ailments.

Prevalencia de trastornos psiquiátricos por uso de alcohol y otras sustancias en hombres y mujeres hospitalizados en medicina interna de un hospital de Santiago de Chile / Prevalence of substance abuse among patients hospitalized in an internal medicine service from Santiago de Chile

Background: Studies done in Chile and abroad report a high frequency of substance abuse among patients hospitalized in general medical services. Aim: To report the frequency of substance abuse in a sample of patients hospitalized in a public hospital of Santiago. Material and methods: A structured psychiatric interview for the Third Revised Version of The Diagnostic and Statistical Manual (DSM-III-R) was applied to 203 males, aged 58.5 years and 203 females, aged 52,9 years, hospitalized in an internal medicine Service of a public hospital. All subjects had a low educational and income level. Results: The discharge diagnoses of studied patients were digestive diseases in 32 percent, circulatory diseases in 19 percent, cancer, diabetes mellitus and genitourinary diseases in 11 percent respectively and mental or behavioral diseases in 5 percent. Thirty eight percent of males and 6 percent of females qualified for alcohol dependency or abuse in some moment of their lives. The figures for benzodiazepine dependency were 1 percent among males and 6 percent among females. The figures for cannabis, cocaine or stimulant abuse were 1.5 percent for males and 1 percent for females. Other conditions of the axis 1 of DSM-IIIR were diagnosed in 47 percent of males and 65 percent of females with substance abuse. Conclusions: Substance abuse underlies medical conditions in a high proportion of patients admitted to medical services in general hospitals

Prevalencia de trastornos psiquiátricos en hombres y mujeres hospitalizados en un servicio de medicina interna de un hospital de Santiago de Chile / Prevalence of psychiatric disorders among subjects hospitalized in a medicine ward of a general hospital

Background: Mental disorders may interfere, aggravate or mimic medical conditions. Aim: To study the prevalence of psychiatric disorders among patients hospitalized in a medical ward of a general hospital. Patients and methods: A structured interview for DSM-III, devised for "non patients", was applied to 203 men and 203 women, aged 11 to 90 years old, hospitalized in an internal medicine service of a public hospital. Thirty four psychiatric conditions that can be discriminated with the instrument and others that complied with DSM-III criteria, were investigated. Results: There was a 60 percent prevalence of mental disorders among men (alcohol dependency in 26 percent, delirium or dementia in 10.8 percent, anxiety disorders in 10.4 percent, major depression in 7.8 percent and adaptation disorders in 3 percent). Among women, the prevalence of mental disorders was 65 percent (major depression in 23.2 percent, anxiety disorders in 14.3 percent, adaptation disorders in 8.4 percent, dementia in 5.6 percent, delirium in 3 percent and alcohol dependency in 2.5 percent). Most conditions were of moderate or mild intensity. Two or more conditions coexisted in 40 percent of cases. Only in 8 percent of these subjects, a psychiatric consultation was requested. Conclusions: There is a high frequency of psychiatric disorders among medical patients. These must be adequately diagnosed and treated

La conducta suicida en mujeres: un estudio prospectivo / Study of female suicide attempters: a 5 years follow up

Background: A previous suicide attempt is one of the strongest predictors of future suicidal behavior. Aim: To explore the evolution of suicidal tendencies in women who attempted suicide 5 to 7 years earlier. Patients and methods: Ninety two women aged 37 ñ 9 years old, that attempted suicide between 1989 and 1991 were followed and reassessed in 1997. Results: In the study period two women committed suicide and 30 attempted suicide. Forty three percent of new self harm behaviors occurred during the first year after the first suicide attempt and the harming method was similar. Conclusions: In this study, 34percent of women with previous suicide attempts, repeated this behavior, using similar methods

Estudio clínico-descriptivo del síndrome de Cotard / Clinical-descriptive study of Cotard's syndrome

Con motivo de la presentación de un caso de un niño con un violento síndrome de hiperpirexia ficticia se hace una exposición diagnóstica diferenciativa de los diversos síndromes de autoinducción voluntaria o síndromes de ficción y se aislan de ellos los cuadros clínicos de histerismo y de simulación simple. Se comenta también el concepto moderno del síndrome de Münchhausen y el sentido terapéutico actual de todos estos procesos