Survey on schizophrenia treatment in Mexico: perception and antipsychotic prescription patterns

BACKGROUND: Since the introduction of antipsychotics, especially the so called atypicals, the treatment of schizophrenia has shown important improvements. At the present time, it is preferred to label clozapine and other antipsychotics sharing similar profiles as second-generation antipsychotics (SGAs). These medications have been proposed by some experts as a first line treatment for schizophrenia. It is critical to have reliable data about antipsychotic prescription in Mexico and to create management guidelines based on expert meetings and not only on studies carried out by the pharmaceutical industry. Only this approach will help to make the right decisions for the treatment of schizophrenia. METHODS: A translated version of Rabinowitz's survey was used to evaluate antipsychotic prescription preferences and patterns in Mexican psychiatrists. The survey questionnaire was sent by mail to 200 psychiatrists from public institutions and private practice in Mexico City and Guadalajara, Mexico. RESULTS: Recommendations for antipsychotics daily doses at different stages of the treatment of schizophrenia varied widely. Haloperidol was considered as the first choice for the treatment of positive symptoms. On the contrary, risperidone was the first option for negative symptoms. For a patient with a high susceptibility for developing extrapyramidal symptoms (EPS), risperidone was the first choice. It was also considered that SGAs had advantages over typical antipsychotics in the management of negative symptoms, cognitive impairment and fewer EPS. Besides, there was a clear tendency for prescribing typical antipsychotics at higher doses than recommended and inadequate doses for the atypical ones. CONCLUSIONS: Some of the obstacles for the prescription of SGAs include their high cost, deficient knowledge about their indications and dosage, the perception of their being less efficient for the treatment of positive symptoms and the resistance of some Mexican physicians to change their prescription pattern. It is necessary to reach a consensus, in order to establish and standardize the treatment of schizophrenia, based on the information reported in clinical trials and prevailing economic conditions in Mexico

Low muscarinic receptor binding in prefrontal cortex from subjects with schizophrenia: a study of Brodmann\u27s areas 8, 9, 10, and 46 and the effects of neuroleptic drug treatment

Objective: Aberrant cholinergic inputs and synaptic neurotransmission in the prefrontal cortex induce cognitive impairment, which is a central feature of schizophrenia. Postsynaptic excitatory muscarinic cholinergic M1 and M4 receptors are the major cholinoceptive targets in the prefrontal cortex and hence may be involved in the pathology and/or pharmacotherapeutics of schizophrenia. Method: Using quantitative autoradiography, the authors analyzed the binding of the M1/M4 receptor selective antagonist [3H]pirenzepine in prefrontal cortex (Brodmann\u27s areas 8, 9, 10, and 46) from schizophrenia patients who had (N=6) or had not (N=11) been treated with the anticholinergic agent benztropine mesylate and from normal comparison subjects (N=20). Moreover, preliminary studies of [3H]pirenzepine binding in rat frontal cortex following administration of antipsychotic drugs or benztropine mesylate were performed. Results: Relative to those of comparison subjects, the mean levels of [3H]pirenzepine binding were significantly lower in Brodmann\u27s areas 9 and 46 of the schizophrenia patients not treated with benztropine mesylate (18% lower in Brodmann\u27s area 9 and 21% lower in Brodmann\u27s area 46) and in all four examined regions of the patients who had received benztropine (51%-64% lower). Antipsychotic or anticholinergic drugs tended to increase or have no effect on the density of [3H]pirenzepine-labeled receptors in rat frontal cortex. Conclusions: Because M1 and M4 receptors are critical to the functions of prefrontal cortical acetylcholine, the present findings suggest a functional impairment in cholinergic neurotransmission in schizophrenia and the possibility that muscarinic receptors are involved in the pharmacotherapeutics of the disorder

No change in the density of the serotonin1A receptor, the serotonin4 receptor or the serotonin transporter in the dorsolateral prefrontal cortex from subjects with schizophrenia

Changes in serotonin receptors and the serotonin transporter have been reported in the dorsolateral prefrontal cortex from subjects with schizophrenia, an area of the brain thought to be important in the pathology of the illness. To further our understanding on how such changes could play a role in the pathology of the illness, in situ radioligand binding with autoradiography was used to measure the density of the serotonin1A receptor, the serotonin4 receptor and the serotonin transporter in the dorsolateral prefrontal cortex, obtained at autopsy, from 10 schizophrenic and 10 control subjects. The binding of [3H]8-OH-DPAT to serotonin1A receptor, [3H]GR113808 to the 5HT4 receptor and [3H]citalopram to serotonin transporter was not altered in subjects with schizophrenia. Significantly, only in tissue from the control subjects was there a relationship between age and the density of the serotonin4 receptor in Brodmann\u27s areas 8 (r = 0.71, P = 0.02) and 10 (r = -0.67, P = 0.03). Importantly, this confounding factor did not influence the comparison of the density of serotonin4 receptor in the tissue from the schizophrenic and control subjects. This study has failed to show a difference in the density of serotonin1A receptor, the serotonin4 receptor or the serotonin transporter in the dorsolateral prefrontal cortex (Brodmann\u27s areas 8, 9 and 10) from subjects with schizophrenia. These data suggest that not all serotonergic markers are altered in the dorsolateral prefrontal cortex from schizophrenic subjects

Decreased muscarinic receptor binding in subjects with schizophrenia: A study of the human hippocampal formation

Background: Acetylcholine is important to hippocampal function, including the processes of learning and memory. Patients with schizophrenia show impaired learning and memory and hippocampal dysfunction. Thus, acetylcholinergic systems may be primarily or secondarily disrupted in the hippocampal formation of schizophrenic patients. The present study tested the hypothesis that [3H]pirenzepine-labeled muscarinic cholinergic receptor levels are altered in the hippocampal formation of patients with schizophrenia. Methods: We have used quantitative autoradiography to measure [3H]pirenzepine binding to M1 and M4 receptors in the hippocampal formation from 15 schizophrenic and 18 nonschizophrenic subjects. Results: The mean density of [3H]pirenzepine binding was reduced in all regions studied, including the dentate gyrus, subdivisions of Ammon\u27s Horn (CA1-CA4), subiculum, and the parahippocampal gyrus, of the schizophrenic cohort. Moreover, unlike controls, there was no significant variation between the mean levels of [3H]pirenzepine binding across the subregions of the hippocampal formation from schizophrenic subjects. Conclusions: These findings provide support for a possible involvement of the muscarinic cholinergic system in the pathology and/or treatment of schizophrenia

Serotonin2A receptors are reduced in the planum temporale from subjects with schizophrenia

[3H] ketanserin binding to 5HT2A receptors was measured in the left planum temporale (sensory speech cortex) from schizophrenic and non-schizophrenic (control) subjects using both particulate membranes and tissue sections. There was a significant decrease in the affinity of [3H] ketanserin binding to particulate membranes from schizophrenic subjects who were treated with phenothiazines up to death. Adding 2 nM chlorpromazine to brain tissue from control subjects caused a similar decrease in the affinity of [3H] ketanserin binding to particulate membranes. This suggests that the decrease in affinity observed in the phenothiazine-treated subjects was due to residual drugs. In addition, there was a significant decrease in the density of [3H] ketanserin binding in both particulate membranes and tissue sections from schizophrenic subjects which did not appear to be due to residual antipsychotic drugs. Analysis of the laminar distribution of 5HT2A receptors showed that this decrease was greatest in cortical layer III. The decrease in the density of 5HT2A receptors was significant whether schizophrenic subjects were receiving phenothiazines or haloperidol at the time of death, and there was no correlation between the last recorded dose of antipsychotic drug and 5HT2A receptor density. These data suggest that a decrease in the density of 5HT2A receptors in the planum temporale may be associated with the pathology of schizophrenia

A New phenomenological survey of auditory hallucinations : evidence for subtypes and implications for theory and practice

A comprehensive understanding of the phenomenology of auditory hallucinations (AHs) is essential for developing accurate models of their causes. Yet, only 1 detailed study of the phenomenology of AHs with a sample size of N ≥ 100 has been published. The potential for overreliance on these findings, coupled with a lack of phenomenological research into many aspects of AHs relevant to contemporary neurocognitive models and the proposed (but largely untested) existence of AH subtypes, necessitates further research in this area. We undertook the most comprehensive phenomenological study of AHs to date in a psychiatric population (N = 199; 81% people diagnosed with schizophrenia), using a structured interview schedule. Previous phenomenological findings were only partially replicated. New findings included that 39% of participants reported that their voices seemed in some way to be replays of memories of previous conversations they had experienced; 45% reported that the general theme or content of what the voices said was always the same; and 55% said new voices had the same content/theme as previous voices. Cluster analysis, by variable, suggested the existence of 4 AH subtypes. We propose that there are likely to be different neurocognitive processes underpinning these experiences, necessitating revised AH models.11 page(s