Papers by Nicolás Ramírez
European Neuropsychopharmacology, 2002
European Neuropsychopharmacology, 1999
Psychiatry Research, 2003
The 5-HT2A receptor binding parameters using [3H]ketanserine and its intracellular signal inosito... more The 5-HT2A receptor binding parameters using [3H]ketanserine and its intracellular signal inositol 1,4,5 trisphosphate (IP3) concentrations were determined in platelets from schizophrenic patients so as to assess differences with respect to a control group and to a standardized antipsychotic drug treatment. Seventy-five antipsychotic-free patients with a DSM-IV diagnosis of paranoid schizophrenia were included in the study. Blood samples were collected before the onset of antipsychotic treatment (baseline values) and after 3 weeks of treatment. Antipsychotic-free schizophrenic patients showed significantly increased basal 5-HT2A densities in comparison to the control group, together with a significantly increase (23%) in the 5-HT2A binding density in those patients treated with risperidone. These changes could be attributed to an up-regulation of 5-HT2A receptors caused by previous treatment with antipsychotic drugs, which is consistent with the chronic effect of 5-HT2A antagonists to up-regulate the number of binding sites. With regard to second messenger IP3 concentrations, basal concentrations in schizophrenic patients were not significantly different from control values, nor was there any significant difference between basal vs. posttreatment values. These results are possibly related to failure of second messenger systems of 'translating' extracellular messages generated presynaptically into effective neurotransmitter signals in schizophrenic patients.
Schizophrenia Research, 2004
European Psychiatry, 2003
A single case of a patient suffering from a first psychotic episode and the differential diagnose... more A single case of a patient suffering from a first psychotic episode and the differential diagnoses between affective and psychosis is performed throughout the combined use of peripheral serotonergic markers and clinical psychopathological scales during a 6-months follow-up. The results suggest the need of performing further studies combining biological and clinical markers of psychiatric disorders.
European Neuropsychopharmacology, 2003
Psychiatry Research, 2007
The purpose of this study was to determine whether platelet serotonin-2A (5-HT 2A ) binding sites... more The purpose of this study was to determine whether platelet serotonin-2A (5-HT 2A ) binding sites and inositol 1,4,5 trisphosphate (IP3) concentrations before treatment can identify olanzapine-responsive patients. The study included 21 never medicated, first-episode schizophrenia patients (antipsychotic-naïve) and 21 patients with a DSM-IV-TR diagnosis of paranoid schizophrenia who had not received depot antipsychotic treatment in the previous 6 months or oral antipsychotic or antidepressant treatment in the previous 2 months (antipsychotic-free). In the antipsychotic-naïve group, olanzapine responders had a significantly lower number of 5-HT 2A receptors and lower IP3 concentrations at baseline than non-responders. The combination of baseline 5-HT 2A and IP3 values significantly predicted an improvement in negative symptomatology after 6 weeks of treatment with olanzapine. In the antipsychotic-free group, responders had significantly higher positive and lower negative symptomatology at baseline, together with a reduced number of 5-HT 2A receptors. However, basal 5-HT 2A receptors or IP3 concentrations did not significantly predict positive, negative or general clinical response. The reported results suggest that platelet 5-HT 2A binding might be a trait marker that could help to identify those patients likely to show greater improvement in negative symptomatology after olanzapine treatment.
European Neuropsychopharmacology, 2004
European Neuropsychopharmacology, 2001
Psychiatry Research, 2010
Human Psychopharmacology-clinical and Experimental, 2007
ObjectiveA post-hoc analysis of the data from a randomised clinical trial involving prescription ... more ObjectiveA post-hoc analysis of the data from a randomised clinical trial involving prescription of antipsychotic treatment to never treated first-onset psychotic patients was used to compare the weight change after 6-week olanzapine treatment (standard tablets vs. orally disintegrating formulation).A post-hoc analysis of the data from a randomised clinical trial involving prescription of antipsychotic treatment to never treated first-onset psychotic patients was used to compare the weight change after 6-week olanzapine treatment (standard tablets vs. orally disintegrating formulation).MethodIn the subgroup of 38 patients randomised to olanzapine, standard olanzapine tablets were non-randomly and consecutively prescribed to the first 19 patients, with the orally disintegrating formulation being prescribed to the following 19 patients.In the subgroup of 38 patients randomised to olanzapine, standard olanzapine tablets were non-randomly and consecutively prescribed to the first 19 patients, with the orally disintegrating formulation being prescribed to the following 19 patients.ResultsAfter 6-week treatment with olanzapine, a significant higher increase in weight was noted in those patients on standard tablets (mean weight increase 6.3 ± 1.9 Kg) as compared to those on orally disintegrating olanzapine (mean weight increase 3.3 ± 3.2 Kg) (F = 7.7; p = 0.009). BMI increase was also significantly higher in the olanzapine tablet group (mean increase of 2.1 Kg/m2 as compared with 1.1 Kg/m2 in the orally disintegrating group) (F = 4.7; p = 0.036). Substantial weight gain (SWG) (≥7% increase from baseline weight) was noted in 84.2% (n = 16) of the olanzapine tablet patients and in 31.6% (n = 6) of the orally disintegrating olanzapine patients, with the olanzapine tablet group showing a significant increase in the mean percentage of weight gain (F = 4.0; p = 0.014).After 6-week treatment with olanzapine, a significant higher increase in weight was noted in those patients on standard tablets (mean weight increase 6.3 ± 1.9 Kg) as compared to those on orally disintegrating olanzapine (mean weight increase 3.3 ± 3.2 Kg) (F = 7.7; p = 0.009). BMI increase was also significantly higher in the olanzapine tablet group (mean increase of 2.1 Kg/m2 as compared with 1.1 Kg/m2 in the orally disintegrating group) (F = 4.7; p = 0.036). Substantial weight gain (SWG) (≥7% increase from baseline weight) was noted in 84.2% (n = 16) of the olanzapine tablet patients and in 31.6% (n = 6) of the orally disintegrating olanzapine patients, with the olanzapine tablet group showing a significant increase in the mean percentage of weight gain (F = 4.0; p = 0.014).ConclusionsPartial sublingual absorption occurring with orally disintegrating olanzapine may bypass gastrointestinal metabolisation and hence lead to differences in metabolite versus parent compound ratios. However, the need arises to replicate the present study with a longer follow-up. Copyright © 2007 John Wiley & Sons, Ltd.Partial sublingual absorption occurring with orally disintegrating olanzapine may bypass gastrointestinal metabolisation and hence lead to differences in metabolite versus parent compound ratios. However, the need arises to replicate the present study with a longer follow-up. Copyright © 2007 John Wiley & Sons, Ltd.
Schizophrenia Research, 2008
One-hundred patients with a first episode of psychosis, antipsychotic-naïve, were randomized to h... more One-hundred patients with a first episode of psychosis, antipsychotic-naïve, were randomized to haloperidol, olanzapine, risperidone, quetiapine or ziprasidone. Patients were evaluated at baseline, at weeks 6 and 12 and at 3-month intervals. The SCID was used for diagnostic purposes. Symptom levels were measured by the PANSS and the CDSS. Global functioning was measured by the GAF. Premorbid functioning was measured by the PAS. Drug and alcohol abuse was measured by urine test. A brain SPECT was performed at baseline and at 6 weeks. Neuropsychological assessment was performed at 6 weeks and at 12 months. Blood collection for genetic, metabolic and neurochemical analysis was performed at baseline and at every evaluation. Results: Mean age of the patients was 25±7 years, 70% men, 84% single, 83% with primary or secondary school level. The final diagnosis was schizophrenia (47%), schizophreniform disorder (19%) or Psychotic Disorder not specified (13%). Most patients were using alcohol (78%), cannabis (51%), designer drugs (30%) or cocaine (20%). Patients without drug consumption presented the first psychotic episode 9 years later than patients with active drug consumption (ANOVA=7.1; p=0.000). A logistic regression analysis (χ 2 =24.8; df=8; p=0.002) revealed that 8 factors (age, sex, DUP, schizophrenia, premorbid adjustment, alcohol, cannabis, and cocaine use) were associated with the level of remission. Conclusions: Low baseline 5-HT2A binding density significantly predicted clinical response to olanzapine. Olanzapine and risperidone showed the highest retention rates (time in treatment) (Kaplan-Meyer intention-to-treat analysis).
European Psychiatry, 2007
Theorists have proposed that depression is associated with abnormalities in the behavioral activa... more Theorists have proposed that depression is associated with abnormalities in the behavioral activation (BAS) and behavioral inhibition (BIS) systems. In particular, depressed individuals are hypothesized to exhibit deficient BAS and overactive BIS functioning. Self-reported levels of BAS and BIS were examined in 62 depressed participants and 27 nondepressed controls. Clinical functioning was assessed at intake and at 8-month follow-up. Relative to nondepressed controls, depressed participants reported lower BAS levels and higher BIS levels. Within the depressed group, lower BAS levels were associated with greater concurrent depression severity and predicted worse 8-month outcome. Levels of both BIS and BAS showed considerable stability over time and clinical state. Overall, results suggest that BAS dysregulation exacerbates the presentation and course of depressive illness.
Current Psychiatry Reviews, 2006
Abstract: Depressive symptoms in schizophrenia patients are not usually the primary therapeutic g... more Abstract: Depressive symptoms in schizophrenia patients are not usually the primary therapeutic goal, as the psychiatric evaluation of the schizophrenia is generally based in the assessment of the positive and negative syndrome. However, di-rect approach of the pure depressive ...
Acta Psychiatrica Scandinavica, 2009
Objective: The study aimed to establish clinical predictors of non-affective acute remitting psy... more Objective: The study aimed to establish clinical predictors of non-affective acute remitting psychosis (NARP) and assess whether these patients showed a distinct serotonergic profile.Method: First-episode never treated psychotic patients diagnosed of paranoid schizophrenia (n = 35; 21 men and 14 women) or NARP (n = 28; 15 men and 13 women) were included.Results: NARP patients showed significantly lower negative symptomatology, better premorbid adjustment, shorter duration of untreated psychosis, more depressive symptomatology and a lower number of 5-HT2A receptors than the paranoid schizophrenia patients. In the logistic regression, the four variables associated with the presence of NARP were: low number of 5-HT2A receptors; good premorbid adjustment; low score in the item ‘hallucinatory behaviour’ and reduced duration of untreated psychosis.Conclusion: Our findings support the view that NARP is a highly distinctive condition different from either affective psychosis or other non-affective psychosis such as schizophrenia, and highlight the need for its validation.
Schizophrenia Research, 2004
European Neuropsychopharmacology, 2003
Gerente de la Fundación Cobao ac N. de Ed. Las citas que aparecen en la presente guía -transcrita... more Gerente de la Fundación Cobao ac N. de Ed. Las citas que aparecen en la presente guía -transcritas de fuentes impresas o de páginas digitales-, no fueron intervenidas ni modificadas, ya que son textuales.
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Papers by Nicolás Ramírez