ABSTRACT
Evidence from recent studies about the epidemiology of panic disorder (PD) indicates that it is present in 4.7% of general population. In Mexico City, 2.9% of females and 1.9% of males are affected by this disease. Due to the incidence cited above, it is considered an important mental health problem that has impacted social, labor and familiar areas. On the other hand, PD is frequently present in comorbidity with other disorders like major depression, social phobia and generalized anxiety disorder. Moreover, in some cases, it may lead to a suicide risk. PD is characterized by recurrent, unexpected panic attacks, and is commonly associated with agoraphobia. A panic attack is defined as a discrete period of fear or discomfort that includes physical, cognitive and behavioral symptoms. Physical symptoms comprise short breath, palpitations, sweating, dizziness, gastrointestinal discomfort, and chest pain. Cognitive symptoms are associated with catastrophic interpretation of bodily sensations; behavioral symptoms are mainly avoidant of different places, situations and actions that patient had associated with fear of loss of control. In the past few years there has been a growing interest in the neuropsychology of anxiety disorders. Neuropsychological evaluation is relevant because it implies an objective assessment of the cognitive and behavioral abilities and weaknesses that make possible the prediction of the course of the disorder and the effects of treatment modalities. One of the most important contributions of neuropsychological evaluation is the identification of stable patterns of cognitive profiles of a specific disorder considered as neurocognitive endophenotypes. Some recent studies have demonstrated the relationship between neuropsychological alterations and anxiety; nevertheless, most of them were observed in obsessive-compulsive disorder patients. On the other hand, studies examining neuropsychological functioning in PD patients are scarce and report conflicting results. The main objective of the present study was to evaluate whether PD patients with and without agoraphobia, who attended the National Institute of Psychiatry <
De acuerdo a Kessler, el 4.7% de la población general presenta Trastorno de Pánico (TP) a lo largo de la vida, específicamente en la Ciudad de México el TP tiene una prevalencia en la vida de 1.1% en los hombres y de 2.5% en las mujeres, por lo que se considera un problema de gran relevancia. Aunado a esto, uno de los grandes problemas de este padecimiento es el alto índice de comorbilidad que presenta con otros trastornos psiquiátricos como la depresión mayor, la fobia social, el trastorno por ansiedad generalizada y el abuso de sustancias. De acuerdo con el DSM-IV-TR, el TP se caracteriza por la aparición de crisis de angustia inesperadas y recurrentes, inquietud persistente por la posibilidad de tener más crisis, preocupación por las implicaciones de las mismas o sus consecuencias y/o un cambio significativo del comportamiento relacionado con ellas. La evaluación neuropsicológica es relevante, ya que a través de ésta es posible obtener una valoración objetiva que permite conocer las habilidades y déficits cognoscitivos y conductuales de los pacientes con trastornos psiquiátricos para hacer una predicción sobre el curso de la enfermedad, elegir el tipo de tratamiento de forma objetiva, identificar patrones estables de déficits neuropsicológicos así como establecer estrategias que mejoren el pronóstico del trastorno. Diversos estudios han demostrado recientemente la relación entre algunas alteraciones neuropsicológicas y la ansiedad; sin embargo, la mayoría de éstos se han centrado en el trastorno obsesivo-compulsivo. Aunado a esto, los resultados encontrados en investigaciones que han evaluado las funciones cognitivas en el TP, no han sido consistentes. El objetivo del presente estudio fue determinar si existen déficits neuropsicológicos en pacientes diagnosticados con TP con o sin agorafobia que acudieron al servicio de preconsulta del Instituto Nacional de Psiquiatría Ramón de la Fuente, en comparación con sujetos control en los dominios de atención, memoria y funciones ejecutivas. Se seleccionaron dos grupos: uno de 24 sujetos diagnosticados con TP, de acuerdo al DSM-IV-TR, sin tratamiento farmacológico y/o psicoterapéutico previo; y otro de 24 sujetos sanos comparados formando pares por sexo, edad y escolaridad con el primero. Se les aplicó una batería neuropsicológica (Neuropsi Atención y Memoria) que evalúa orientación, atención y concentración, memoria de trabajo, memoria verbal y visual, y funciones ejecutivas y motoras. El Neuropsi Atención y Memoria cuenta con normas obtenidas en la población mexicana, considerando la edad y la escolaridad. Las diferencias en el desempeño cognitivo entre el grupo control y el grupo con TP fueron analizadas por medio de un Análisis de Varianza (con p<0.05). Los resultados mostraron que los sujetos con TP puntuaron significativamente más bajo que los controles en el puntaje total de atención y memoria, en el puntaje del total de atención y funciones ejecutivas, y el total de memoria. El análisis de las subpruebas específicas reveló déficits en la memoria verbal, la memoria visoespacial inmediata y la evocada, y en diversas funciones ejecutivas: formación de categorías, fluidez verbal semántica y fonológica, y fluidez no verbal. Los hallazgos encontrados en este estudio apoyan la noción de que la ansiedad (específicamente el TP) afecta la memoria verbal y la visoespacial así como las funciones ejecutivas. Los pacientes con TP mostraron alteraciones significativas en tareas que requieren de la capacidad de cambiar de foco de atención, flexibilidad en los procesos cognitivos, capacidad de inhibir respuestas inadecuadas, memoria a corto plazo y memoria de trabajo.
ABSTRACT
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Abstract: Panic disorder is a complex phenomenon according to its biochemical and psychosocial etiology. Therapeutic interventions of panic disorder are aimed to promote effectiveness through the combined use of medication and behavioral cognitive therapy. Anxiety is a normal human response. Moderate levels of anxiety are well accepted because they act as an aid to improve performance, and high levels of anxiety are experienced as normal if they are consistent with the demands of the situation. Persons with anxiety disorders complain of experiencing anxiety too often but they seek help also to overcome fears they recognize as irrational and intrusive. From a psychological point of view, behavioral cognitive techniques -such as hyperventilation control, exposure, and cognitive therapy- and structured problem solving have been successful in the treatment of the symptoms associated to anxiety. It is worth to emphasize that graded exposure is perhaps the most powerful technique assisting patients to overcome fearful situations. Cognitions are also important because it has been found that panic attacks occur when people process information in the external environment, as well as internal somatic stimuli, as though they were threatening experiences. In other words, they feel they have no control over their sensations. Panic attacks prevalence in Mexico City is 1.1% in men and 2.5% in women. It is more frequent among 25-to 34- year old single men and married women, with an average scholarity between 7 and 9 years. From a biological point of view, it is suggested that the etiology of panic attacks involves the participation of the serotonergic and adrenergic neurotransmitter systems, as well as the GABA/ benzodiacepine. Studies based on the noradrenergic theory had lead to conclude that panicking patients have more sensitive brainstem carbon dioxide receptors than normal control subjects. At the same time, other lines of work indicate that serotonergic transmission may also play an important role in the genesis of panic attacks. It has been found that patients with panic disorder may have a lower tolerance threshold to methoclorophenylpiperazine response than control subjects because of hypertensive serotonergic receptors. The accumulated laboratory evidence seems to support the idea that panic attacks begin with the stimulation of irritable foci in one of three brainstem areas: the medullary chemoreceptors, the noradrenergic pontine locus coeruleus, or the serotonergic midbrain dorsal raphe. On the other hand, biofeedback is a psychophysiological intervention that allows in the first place for the external control of some of the physical symptoms involved in this disorder, which is later transferred to internal control of psychophysiological cognitions and behaviors that enable the patient to prevent symptom's occurrence. Based on the principles of the General Systems Theory, biofeedback utilizes the concepts of self regulation and disregulation to describe the conditions under wich normally integrated self-regulatory systems may become imbalanced with regard to their positive and negative feedback loops. Technically, all that a person needs to do is to attend to the signals feedback and not to "try" to control them; the effects of a positive feedback loop should occur automatically, without conscious awareness, as long as the person processes the stimuli. Biofeedback has been effectively used in the treatment of essential hypertension, migraine headaches, Raynaud's disease, tension headaches, temporomandibular joint syndrome, asthma, primary dysmenorrhea, peptic ulcers, fecal incontinence, and conditioning of electroencephalographic rhythms, among other problems. The present study reports data from 32 panic disorder outpatients from the National Psychiatry Institute, Mexico City. They were randomly assigned to: Control Group (N = 14): daily doses of 75 milligrams of imipramine. The participants of this group were required to assist to the psychology department in order to obtain a baseline (pre-test and post-test) with the biofeedback equipment. In addition, every two weeks they visited a psychiatrist who verified that there were no collateral effects from the medicament. Experimental Group (N = 18): besides daily doses of imipramine, and visits to the psychiatrist, these patients went through eight multimodal biofeedback and behavioral cognitive techniques which were assisted with relaxation training sessions. All biofeedback sessions lasted 30 minutes divided in six five-minute trails. The first and final trials served to stabilize the biological responses, and the four middle trials were used to give biofeedback and reinforcement to the response being trained in addition to the verbal explanation of the changes occurring on the screen of the computer. All patients were assessed with the Anxiety Sensitivity Index, and with Beck's Anxiety and Depression Inventories. Results showed that patients in the experimental group reported significant lower scores in the anxiety sensitivity index than the control group. Post-test differences showed that the electromiographic and electrodermic activity from the experimental group was lower than the one from the control group. Diaphragmatic respiration training and progressive muscular relaxation and imagery proved to be effective in reducing the symptoms associated to panic attacks. The overall final result is that all patients improved clinically. They verbally reported that the intensity, frequency and evitative behaviors derived from panic attacks had almost disappeared. However, the cognitive factor of anxiety sensitivity changed significanty only in the experimental group. These findings support the hypothesis that clinical improvement results from a symptom "reattribution" which gives them cognitive skills to cope with stressing stimuli. Further studies should reassess the effectiveness of the combined treatment (imipramine and behavioral cognitive techniques). It is also recommended to expand the study to generalized anxiety disorder and to adjust the experimental design in order to incorporate a second phase with neurofeedback as independent variable. Equally important is to investigate the mechanisms of the hypnotic ability and its impact on the clinical improvement of anxiety disorders.