Background: Some studies suggest individuals with schizophrenia have an increased risk of diabetes prior to antipsychotic use. Small sample sizes and the potential for confounding by hypercortisolaemia have decreased confidence in those results.Aims: To examine diabetes-related factors in newly diagnosed, antipsychotic-naive people with non-affective psychosis.Method: Participants with psychosis (the psychosis group;n= 50) and matched controls (the control group;n= 50) were given a 2 h oral glucose tolerance test. Fasting concentrations were also determined for adiponectin, interleukin-6 and C-reactive protein.Results: Compared with the control group, the psychosis group had significant increases in 2 h glucose and interleukin-6 concentrations, and in the prevalence of abnormal glucose tolerance (16% of psychosis groupv.0% of control group). Adiponectin and C-reactive protein concentrations did not differ significantly between the two groups. These findings could not be attributed to differences in cortisol concentrations, smoking, gender, neighbourhood of residence, body mass index, aerobic conditioning, ethnicity, socioeconomic status or age.Conclusions: Individuals with non-affective psychosis appear to have an increased prevalence of abnormal glucose tolerance prior to antipsychotic treatment, as well as abnormalities in a related inflammatory molecule. These underlying problems may contribute to the metabolic side-effects of antipsychotic medications.
Schizophrenia disorder remains an unsolved puzzle. However, the integration of recent findings from genetics, molecular biology, neuroimaging, animal models and translational clinical research offers evidence that the synaptic overpruning hypothesis of schizophrenia needs to be reassessed. During a critical period of neurodevelopment and owing to an imbalance of excitatory glutamatergic pyramidal neurons and inhibitory GABAergic interneurons, a regionally-located glutamate storm might occur, triggering excessive dendritic pruning with the activation of local dendritic apoptosis machinery. The apoptotic loss of dendritic spines would be aggravated by microglia activation through a recently described signaling system from complement abnormalities and proteins of the MHC, thus implicating the immune system in schizophrenia. Overpruning of dendritic spines coupled with aberrant synaptic plasticity, an essential function for learning and memory, would lead to brain misconnections and synaptic inefficiency underlying the primary negative symptoms and cognitive deficits of schizophrenia. This driving hypothesis has relevant therapeutic implications, including the importance of pharmacological interventions during the prodromal phase or the transition to psychosis, targeting apoptosis, microglia cells or the glutamate storm. Future research on apoptosis and brain integrity should combine brain imaging, CSF biomarkers, animal models and cell biology.
1 May 2005 in International Clinical Psychopharmacology
The maintained antipsychotic efficacy of risperidone long-acting injectable (RLAI) was investigated in patients with schizophrenia or other psychoses who were transitioned directly from their previous antipsychotic medication. Patients symptomatically stable, but considered to require a treatment change, received 25 mg of RLAI (increased to 37.5 or 50 mg, if necessary) every 2 weeks for 6 months. Assessments included Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Severity (CGI-S), Global Assessment of Functioning (GAF), SF-36 Health-Related Quality of Life Questionnaire and Extrapyramidal Symptoms Rating Scale (ESRS). Of 1876 patients enrolled, 74% completed the 6-month study. The most frequent reasons for treatment change were non-compliance (38%), insufficient efficacy (33%) and side-effects (26%). There was a significant reduction from baseline to endpoint in mean total PANSS score and in the scores on all PANSS subscales and symptom factors (P<0.001). CGI-S improved significantly, as did mean GAF score, all factors on the SF-36 and patient satisfaction with treatment. Scores on ESRS showed significant, sustained improvements throughout the study period. Direct initiation of RLAI was effective and well tolerated. RLAI provides an advancement in the treatment options available for a wide range of patients requiring long-term antipsychotic therapy.
Recent studies suggest that in addition to factors such as treatment side effects, suicide, and poor health habits, people with schizophrenia may have an increased risk of diabetes prior to antipsychotic treatment. Diabetes is associated with an increased pulse pressure (PP) and a shortened telomere. We tested the hypothesis that prior to antipsychotic treatment, schizophrenia and related disorders are associated with a shortened telomere, as well as an increased PP. Telomere content (which is highly correlated with telomere length) and PP were measured in newly diagnosed, antipsychotic-naive patients with schizophrenia and related disorders on first clinical contact and in matched control subjects. Both groups were also administered an oral glucose tolerance test. Compared with control subjects, the patients with psychosis had decreased telomere content and an increased PP. As previously reported, they also had increased glucose concentrations at 2 hours. These differences could not be attributed to differences in age, ethnicity, smoking, gender, body mass index, neighborhood of residence, socioeconomic status, aerobic conditioning, or an increased cortisol concentration in the psychotic subjects. These results suggest that prior to antipsychotic use, nonaffective psychosis is associated with reduced telomere content and increased PP, indices that have been linked to an increased risk of diabetes and hypertension.