Atypical antipsychotics normalize low-gamma evoked oscillations in patients with schizophrenia.

The symptoms of schizophrenia might be mediated by a cortical network disconnection which may disrupt the cortical oscillatory activity. Steady-state responses are an easy and consistent way to explore cortical oscillatory activity. A chirp-modulated tone (increasing the frequency of the modulation in a linear manner) allows a fast measure of the steady-state response to different modulation rates. With this approach, we studied the auditory steady-state responses in two groups of patients with schizophrenia (drug-naive and treated with atypical antipsychotic drugs), in order to assess the differences in their responses with respect to healthy subjects, and study any potential effect of medication. Drug-naive patients had reduced amplitude and inter-trial phase coherence of the response in the 30-50Hz range, and reduced amplitude of the response in the 90-100Hz range, when compared to controls. In the treated patients group, the response in the 30-50Hz range was normalized to values similar to the control group, but the reduction in amplitude in the 90-100Hz range remained as in the drug-naive group. These results suggest that gamma activity impairment in schizophrenia is a complex phenomenon that affects a wide band of frequencies and may be influenced by antipsychotic treatment.

Geniuses of medical science: Friendly, open and responsible, not mad.

Recent studies based on biography analysis provide support for the notion that the prevalence of mental illness in the creative geniuses of art, literature and science is higher than it is in more ordinary folk. However, this relationship between madness and genius, which was also addressed by the classical philosophers, has been generalized to all branches of professional endeavour. Whilst it may hold true for illustrious personalities of the fine arts, we found that the relationship proves inappropriate to the biographies of ten individuals renowned in history for their innovative contributions to medical science. Furthermore, examination of these ten biographies invites the hypothesis that certain personality traits - especially, agreeableness, conscientiousness and openness to new experience - can act to enhance creativity and protect against mental illness.

Parámetros de inmunidad natural como marcadores biológicos de la depresión / Parameters of natural immunity as biological markers of depression

IntroducciÓn: Durante la depresión se producen cambios en la respuesta inmunitaria natural. Conocer mejor estas alteraciones en el laboratorio podría ayudarnos como complemento en el diagnóstico clínico de la depresión. El objetivo fue seleccionar qué parámetros inmunitarios pueden ser más útiles como marcadores biológicos de la depresión. Sujetos y método: Hemos estudiado distintos parámetros inmunitarios de 42 pacientes deprimidos durante la fase aguda y después de la respuesta al tratamiento, y los comparamos con un grupo de 20 controles sanos. Los parámetros estudiados fueron: recuento de monocitos y de células natural killer (NK), expresión de moléculas de superficie monocitaria HLA-II, CD14, y CD16, producción de citocinas monocitarias (IL-1ß, IL-6, y TNF-alfa), actividad oxidativa e índice de fagocitosis monocitarios, y actividad citotóxica de células NK. Resultados: En los pacientes deprimidos se produjo un aumento de monocitos CD16+, células NK, capacidad oxidativa monocitaria y producción de las citocinas estudiadas (IL-1ß, IL-6 y TNF-alfa), y un descenso de la expresión de HLA-II y del índice de fagocitosis monocitario. De estos parámetros, el índice de fagocitosis (especificidad del 90%; valor predictivo negativo del 99%) y, en menor medida, la producción de TNF-alfa (especificidad del 85%; valor predictivo negativo del 98,9%) fueron los que más podrían ayudar en el diagnóstico clínico de la depresión. Conclusiones: Los resultados indican que el índice de fagocitosis y la producción de TNF-alfa podrían ser marcadores biológicos útiles en la depresión, tanto para el diagnóstico como para el seguimiento evolutivo

Introduction: Immune function is altered in adult patients with depression. Laboratory assessment of these alterations could aid clinical diagnosis of depression. Objectives: To assess which immune parameters are the most reliable biological markers of depression. Subjects and method: We studied immune function in 42 depressed patients during the acute depressive phase and after treatment response, and compared it to that of 20 healthy controls. The following immune parameters were evaluated: monocyte and natural killer (NK) cell count; monocyte surface molecule expression (HLA-II, CD14, and CD16); monocyte cytokine proinflammatory production (interleukin [IL]-1ß, IL-6, and tumor necrosis factor [TNF]-alpha); respiratory burst capacity and monocyte phagocytic index; and NK cytotoxic activity. Results: Depressed patients showed an increase of CD16+ monocytes, NK cell count, respiratory burst activity, and monocyte cytokine production (IL-1ß, IL-6, and TNF-alpha). Depressed patients also showed a decrease in HLA-II molecule expression and phagocytic index. The monocyte phagocytic index (specificity = 90%, and negative predictive value = 99%), and to a lesser extent, TNF-alpha production (specificity = 90%, and negative predictive value = 99%) could be the most reliable immune parameters in the clinical diagnosis of depression. Conclusions: Our results suggest that the monocyte phagocytic index and TNF-alpha production are reliable biological markers of depression

Dysfunctional supplementary motor area implication during attention and time estimation tasks in schizophrenia: a PET-O15 water study.

Results of this PET-O15 water activation study confirm the implication of supplementary motor areas during time estimation tasks. They also show that the cortical-subcortical network associated with temporal processing is impaired in schizophrenia. Following recent proposals of time dynamic networks, this impairment may consist in a dysfunctional imbalance of early failure of supplementary motor activation during temporal processing.

Lymphocyte subsets and lymphokine production in patients with melancholic versus nonmelancholic depression.

Several studies have reported immune changes during depression, but the results have not been fully consistent. Some of these changes could be related to the presence of melancholic features. A total of 42 depressed patients (melancholic [MEL] and nonmelancholic [non-MEL]) and 20 healthy controls participated in the study. We detected a higher CD4+ lymphocyte subset in MEL patients than in controls during the depressive state, which disappeared after clinical remission. We also found an increase in interleukin-2 (IL-2) production both in MEL and non-MEL patients, but these values did not differ from control values after clinical remission. Some of these changes may be related to the melancholic characteristics of depression.