Effects of risperidone on glucose metabolism in Chinese patients with schizophrenia: A prospective study

BackgroundWhile most of the second generation antipsychotic agents are associated with abnormal glucose metabolism, previous studies have shown that risperidone has relatively little effect upon blood glucose levels. This study aimed to explore the effect of risperidone on the glucose-regulating mechanism of patients with schizophrenia by using the oral glucose tolerance test (OGTT), measuring insulin and C-peptide levels.MethodsThirty inpatients with schizophrenia taking risperidone were studied. All the patients were given a simplified OGTT at baseline and six weeks after treatment. Plasma glucose, insulin, and C-peptide concentrations were measured at fasting, then 1 and 2 h after OGTT respectively. Other data, including demographic characteristics and plasma drug concentrations, were also recorded.Results(1) There was no significant increase in the proportion of patients demonstrating abnormal plasma glucose levels compared with baseline (p = 1.000, McNemar test); (2) risperidone was associated with elevated insulin concentrations (p = 0.013), C-peptide levels (p = 0.020), insulin/glucose ratio (p = 0.020) and BMI (p < 0.01); (3) no sex differences in glucose-related measures were observed.ConclusionRisperidone treatment may be associated with alterations in glucose-regulating mechanisms in patients with schizophrenia.     

Insulin resistance and metabolic profile in antipsychotic naïve schizophrenia patients

Objectives

Several studies have suggested insulin resistance related to dyslipidemia and body weight in drug treated schizophrenia patients. Although, insulin resistance or impaired glucose tolerance is also reported in antipsychotic naïve schizophrenia patients, their relationship with dyslipidemic changes and body weight is not well established. The present study was undertaken to examine insulin resistance in antipsychotic naïve schizophrenia patients of this region and to evaluate any association between lipid parameters and body weight with their insulin resistance, if any.

Method

Plasma glucose, total serum cholesterol and its LDL, HDL fractions, and serum insulin levels were measured from fasting blood samples of newly diagnosed, antipsychotic naïve schizophrenia patients (n = 30) and matched control group (n = 25) in a hospital based case control study. Homoeostatic model assessment (HOMA) was done to evaluate insulin resistance.

Results

Means of plasma glucose, total serum cholesterol and its LDL, HDL fractions did not vary significantly (p > 0.05) between cases and control. Insulin resistance was significantly increased (p < 0.05) in drug naïve cases. Multiple linear regression analyses did not show any association (p > 0.05) between insulin resistance and lipid parameters.

Conclusions

Newly diagnosed schizophrenia patients were more prone to insulin resistance in our study population. This was not associated with any dyslipidemic changes as the lipid parameters were not elevated in them compared to the healthy controls. It was not dyslipidemia, but some other common genetic or risk factors that might be responsible for the increased insulin resistance in antipsychotic naïve schizophrenia patients in our study population.     

A randomized, placebo-controlled trial of risperidone augmentation for patients with difficult-to-treat unipolar, non-psychotic major depression

Objective

Patients (30-50%) with non-psychotic major depression will not respond despite an adequate trial of antidepressant medication. This study evaluated risperidone as an augmenting agent for patients who failed or only partially responded to an adequate trial of an antidepressant medication.

Method

Ninety-seven patients with unipolar non-psychotic major depression who were not responsive to antidepressant monotherapy were randomized to risperidone (0.5-3 mg/day) or placebo augmentation in a four-week, double-blind, placebo controlled treatment trial. The primary outcome measure was remission defined by a score of ?10 on the Montgomery-Asberg Depression Rating Scale (MADRS). Secondary outcomes measures were the Hamilton Rating Scale for Depression, the Clinician Global Impression of Severity scale and the overall satisfaction item of the Quality of Life and Enjoyment Questionnaire.

Results

Subjects in both treatment groups improved significantly over time. The odds of remitting were significantly better for patients in the risperidone vs. placebo arm (OR = 3.33, p = .011). At the end of 4 weeks of treatment 52% of the risperidone augmentation group remitted (MADRS ? 10) compared to 24% of the placebo augmentation group (CMH(1) = 6.48, p = .011), but the two groups were converging. Patients in the risperidone group also reported significantly more improvement in quality-of-life than patients in the placebo group. There were no between-group differences in the number of adverse events reported, however, weight gain was significantly higher in the group receiving risperidone.

Conclusion

Augmentation of an antidepressant with risperidone for patients with difficult-to-treat depression leads to more rapid response and a higher remission rate and better quality-of-life.     

Subjective awareness of tardive dyskinesia and insight in schizophrenia

Background

Lack of awareness of tardive dyskinesia (TD) and poor insight into mental illness are common in schizophrenia, raising the possibility that these phenomena are manifestations of a common underlying dysfunction.

Methods

We investigated relationships between low awareness of TD and poor insight into mental illness in 130 patients with schizophrenia and TD. We also examined selected demographic and clinical correlates of these two phenomena.

Results

Sixty-six (51%) patients had no or low awareness of TD and 94 (72%) had at least mild impairment of insight into their mental illness. Low awareness of TD was not significantly correlated with greater impairment of insight into mental illness. Regression analyses indicated that the Positive and Negative Syndrome Scale (PANSS) disorganised factor (β = 0.72, t = 11.88, p < 0.01) accounted for 52% of the variance in insight into mental illness (adjusted R² = 0.55) (F[2, 127] = 81.00, p < 0.01) and the Extrapyramidal Symptom Rating Scale (ESRS) dyskinesia subscale score (β = 0.47, t = 6.80, p < 0.01), PANSS disorganised factor (β = −0.26, t = −3.73, p < 0.01), and ESRS parkinsonism subscale score (β = 0.31, t = 4.55, p < 0.01) together accounted for 37% of the variance in awareness of TD (adjusted R² = 0.37) (F[3, 126] = 26.87, p < 0.01).

Conclusion

The two phenomena appear to be dissociated, and may be domain-specific.     

Interictal alterations of cytokines and leukocytes in patients with active epilepsy

Background

Involvement of the innate immune system in the pathogenesis of epilepsies has been suggested but possible interactions between the immune system and human epilepsy remain unclear. We analyzed the interictal immuno-phenotype of leukocyte subsets and proinflammatory cytokine profiles in epileptic patients and correlated them with the epilepsy syndrome.

Methods

101 patients with active focal or generalized epilepsy were prospectively included and compared to 36 healthy controls. Immuno-phenotype of leukocyte subsets and cytokines IL-1β, IL-6 and tnfα were measured in peripheral blood. Multivariate analyses were performed to test group differences.

Results

As compared to controls, the patients showed an elevated percentage of monocytes (18.06 ± 7.08% vs. 12.68 ± 4.55%, p < 0.001), NK cells (14.88 ± 7.08% vs. 11.43 ± 5.41%, p = 0.019) and IL-6 concentration (3.33 ± 3.11 pg/ml vs. 1.5 ± 1.36 pg/ml, p = 0.002). This remained true when focal epilepsies or generalized epilepsies were compared separately to controls but only focal epilepsies showed additionally a decrease in B lymphocyts (8.16 ± 3.76% vs. 11.54 ± 4.2%, p < 0.001). Treatment with lamotrigine was associated with a higher percentage of B lymphocytes and valproate with an increased percentage of CD4⁺ T lymphocytes. Therapy with levetiracetam showed a trend towards decreased CD8⁺ T cell counts. No significant differences were seen between focal and generalized epilepsies and between temporal and extratemporal lobe epilepsies.

Conclusion

Patients with active epilepsy revealed interictal alterations of the immune system which varied among specific syndromes and were influenced by antiepileptic drug treatment.     

Gender differences in the effects of peroxisome proliferator-activated receptor γ2 gene polymorphisms on metabolic adversity in patients with schizophrenia or schizoaffective disorder

Objective

Metabolic syndrome (MS) is a major health problem in schizophrenic patients. Peroxisome proliferator-activated receptor γ2 (PPARγ2) is one of the candidate genes responsible for the liability to metabolic problems. In this study, we investigated the effect of the PPARγ2 gene Pro12Ala and C161T polymorphisms on metabolic adversities in patients with schizophrenia or schizoaffective disorder.

Methods

Metabolic profiles and PPARγ2 gene polymorphisms were determined in 600 patients (309 men and 291 women) with a clinical diagnosis of schizophrenia or schizoaffective disorder. Metabolic indices and components of MS were compared between patients with different Pro12Ala or C161T genotypes.

Results

In the whole population, the allele frequency of 12Ala and 161T was 4.4% and 24.7% respectively. Both polymorphisms had no significant effect on obesity or metabolic-related traits. However, following gender stratification of the data, we found female 12Ala allele carriers were at greater risk of developing abdominal obesity (OR = 4.0, 95% CI = 1.1-14.2, p = 0.04) and hypertension (OR = 2.9, 95% CI = 1.2-7.4, p = 0.02) than female 12Ala allele non-carriers. Male 161T allele carriers had lower insulin levels (p = 0.02) and lower high-density lipoprotein cholesterol (HDL-C) (p = 0.05) levels than male 161T allele non-carriers. Moreover, female 161T allele carriers had higher body weight (p = 0.04), waist circumference (p = 0.05), and systolic blood pressure (p = 0.01), and were at greater risk of developing hypertension (OR = 2.0, 95% CI = 1.1-3.5, p = 0.02). Haplotype analyses showed that PPARγ2 gene polymorphisms were significantly associated with HDL-C level in men and blood pressure in women.

Conclusions

We did not find an association of PPARγ2 gene polymorphisms with MS or obesity in our schizophrenia sample. But further analyses by gender stratification revealed gender-specific differences in the effect of different PPARγ2 genotypes on certain metabolic adversities in these patients.     

Effects of haloperidol and risperidone on cerebrohemodynamics in drug-naive schizophrenic patients

Background

Use of antipsychotics may be associated with cerebrovascular adverse events in psychotic patients. In this study, the effects of haloperidol and risperidone on the cerebral hemodynamics and the possible relationships between antipsychotics and cerebrovascular risks tendency were evaluated by Transcranial Doppler ultrasonography (TCD).

Methods

Twenty drug-na?¨ve schizophrenic patients and 20 normal control subjects were included. The patients were divided into haloperidol- and risperidone-treated groups and received treatment for 8 weeks double-blindly. The subjects’ cerebral blood flow mean velocities (MV) and pulsatility index (PI) were measured weekly by TCD. The Positive and Negative Syndrome Scale for schizophrenia (PANSS) was used to assess the patients’ psychopathological symptoms.

Results

Increased MV and decreased PI were found significantly in drug-na?¨ve schizophrenic patients than normal subjects before treatment (p < 0.01). The decreased PI could be normalized after 8 weeks of antipsychotic treatment, while the increased MV could not. Treatment with haloperidol could significantly increase the PI than the treatment with risperidone (p < 0.01) throughout the treatment course. The PANSS scores of both groups were significantly improved (p < 0.05) at the endpoints of treatment.

Conclusions

Our findings indicate that haloperidol may affect the cerebral hemodynamics in drug-na?¨ve schizophrenics more prominently than that of risperidone via TCD monitoring.     

Association of PDE4D and IL-1 gene polymorphism with ischemic stroke in a Han Chinese population

Background

The single-nucleotide polymorphisms (SNPs) of the phosphodiesterase 4D (PDE4D) and interleukin-1 (IL-1) genes are associated with increased risk for the development of ischemic stroke (IS) in whites. However, little is known about whether this association could also occur in Han Chinese.

Method

A total of 371 patients with IS and unrelated healthy controls were recruited and the SNPs of the PDE4D (83T/C), (87T/C), IL-1 (−889C/T) and IL-1 (−511C/T) were characterized, respectively, by polymerase chain reactions-restriction fragment length polymorphism (PCR-RFLP). The genotype and allele frequencies of these SNPs in this population were statistically analyzed.

Results

The genotype and allele frequencies of the PDE4D (87T/C) and IL-1 (−511C/T) were similar between IS patients and controls. In contrast, the frequencies of CC genotype and C allele of the PDE4D (83T/C) and the T allele frequency of IL-1 (−889C/T) in IS patients were significantly higher than that in healthy controls (p = 0.001, p = 0.003 and p = 0.02, respectively), independent of the conventional risk factors. The values of odds ratio (OR) reached at OR = 1.603; 95%CI = 1.032-2.489; p = 0.036 for the CC genotype of the PDE4D (83T/C) and OR = 1.913; 95%CI = 1.621-2.375; p = 0.034 for the TT genotype of the IL-1 (−889C/T), respectively.

Conclusions

the SNPs of the PDE4D (83T/C) and IL-1 (−889C/T) were associated with increased risk for the development of IS in Northern Han Chinese.     

A case-control study provides evidence of association for a common SNP rs974819 in PDGFD to coronary heart disease and suggests a sex-dependent effect

Introduction

Peden et al. have revealed a significant association between four new risk loci and coronary heart disease (CHD) in Europeans and South Asians. The goal of this study is to evaluate the contribution of these genetic loci to CHD risk in Han Chinese.

Methods

We recruited 161 CHD patients and 112 controls proved by angiography originated from Ningbo in the Eastern China, and performed a case-control association study of the four significant SNPs.

Results

Among the four tested SNPs, we found a significant association of rs974819 in PDGFD gene with CHD (allele p = 0.04; OR = 1.45, 95% CI = 1.02 - 2.08) and the allele A/G of rs974819 shows significant difference in females (allele p = 0.04; OR = 1.83, 95% CI = 1.01 - 3.31). A further meta-analysis showed that rs974819 of PDGFD gene was significantly associated with an increasing risk of CHD (OR = 1.08, 95% CI = 1.05 - 1.11) in both Europeans and South Asians including Han Chinese.

Conclusions

Our findings suggests that rs974819 of PDGFD is also a CHD risk factor in Han Chinese. In addition, it presents a sex-dependent genetic effect.     

Higher serum clozapine level is associated with increased antiphospholipid antibodies in schizophrenia patients

Objectives

This study was to evaluate the relationship between clozapine and aPL in schizophrenia patients.

Methods

163 Participants were evaluated: 37 unmedicated schizophrenia patients, 50 clozapine-treated schizophrenia patients and 76 age- and sex-matched healthy controls. A fasting blood sample was taken for serum aPL and serum clozapine level. Serum aPL were measured by ELISA technique and HPLC method was used for the determination of serum clozapine level.

Results

The unmedicated schizophrenia patients showed higher IgG aCL level [mean ± SD: 1.51 ± 0.81 and 1.25 ± 0.13 U, respectively (t = 2.77, df=111, p<0.01)] and IgM aCL level [mean±SD: 1.53 ± 0.54. and 1.33 ± 0.15 U, respectively (t = −2.98, df = 111, p < 0.01)] compared with the healthy controls. The comparison of the clozapine-treated schizophrenia patients and the healthy controls showed significant difference in IgG aCL level [mean ± SD: 1.74 ± 0.90 and 1.25 ± 0.13 U, respectively (t = −4.77, df = 124, p < 0.01)] and IgM aCL level [mean ± SD: 1.62 ± 0.83 and1.33 ± 0.15 U, respectively (t = −4.35, df = 124, p < 0.01)]. In clozapine-treated schizophrenia patients, the results of Pearson correlation coefficients showed that there was a significant positive relationship between serum IgM aCL and serum clozapine level (r = 0.461, p < 0.01), and serum IgG aCL were significantly correlated with serum IgM aCL (r = 0.279, p < 0.05). Stepwise multiple regression analysis was performed with various characteristics, such as duration of medication, daily dose and serum clozapine level as candidate factors for serum aCL (IgG and IgM isotypes) in clozapine-treated schizophrenia patients. Only serum clozapine level was able to enter into the regression model of IgM aCL (Model R² = 0.212, p < 0.05).

Conclusions

A higher serum clozapine level is associated with an increased aPL in schizophrenia patients.     

Psychiatric co-morbidities and cardiovascular risk factors in people with lifetime history of epilepsy of an urban community

Objectives

Depression has been consistently reported in people with epilepsy. Several studies also suggest a higher burden of cardiovascular diseases. We therefore analysed psychosocial co-morbidity and cardiovascular risk factors in patients with a lifetime history of epilepsy in the PsyCoLaus study, a Swiss urban population-based assessment of mental health and cardiovascular risk factors in adults aged between 35 and 66 years.

Patients and methods

Among 3719 participants in the PsyCoLaus study, we retrospectively identified those reporting at least 2 unprovoked seizures, defined as epilepsy. These subjects were compared to all others regarding psychiatric, social, and cardiovascular risk factors data using uni- and multivariable assessments.

Results

A significant higher need for social help (p < 0.001) represented the only independent difference between 43 subjects with a history of epilepsy and 3676 controls, while a higher prevalence of psychiatric co-morbidities (p = 0.015) and a lower prevalent marital status (p = 0.01) were only significant on univariate analyses. Depression and cardio-vascular risk factors, as well as educational level and employment, were similar among the groups.

Conclusions

This analysis confirms an increased prevalence of psychosocial burden in subjects with a lifetime history of epilepsy; conversely, we did not find a higher cardiovascular risk. The specific urban and geographical location of our cohort and the age span of the studied population may account for the differences from previous studies.     

In adults with Prader-Willi syndrome, elevated ghrelin levels are more consistent with hyperphagia than high PYY and GLP-1 levels

Objective

Prader-Willi syndrome (PWS) is a leading genetic cause of obesity, characterized by hyperphagia, endocrine and developmental disorders. It is suggested that the intense hyperphagia could stem, in part, from impaired gut hormone signaling. Previous studies produced conflicting results, being confounded by differences in body composition between PWS and control subjects.

Design

Fasting and postprandial gut hormone responses were investigated in a cross-sectional cohort study including 10 adult PWS, 12 obese subjects matched for percentage body fat and central abdominal fat, and 10 healthy normal weight subjects.

Methods

PYY[total], PYY[3-36], GLP-1[active] and ghrelin[total] were measured by ELISA or radioimmunoassay. Body composition was assessed by dual energy X-ray absorptiometry. Visual analog scales were used to assess hunger and satiety.

Results

In contrast to lean subjects (p < 0.05), PWS and obese subjects were similarly insulin resistant and had similar insulin levels. Ghrelin[total] levels were significantly higher in PWS compared to obese subjects before and during the meal (p < 0.05). PYY[3-36] meal responses were higher in PWS than in lean subjects (p = 0.01), but not significantly different to obese (p = 0.08), with an additional non-significant trend in PYY[total] levels. There were no significant differences in self-reported satiety between groups, however PWS subjects reported more hunger throughout (p = 0.003), and exhibited a markedly reduced meal-induced suppression of hunger (p = 0.01) compared to lean or obese subjects.

Conclusions

Compared to adiposity-matched control subjects, hyperphagia in PWS is not related to a lower postprandial GLP-1 or PYY response. Elevated ghrelin levels in PWS are consistent with increased hunger and are unrelated to insulin levels.     

A pilot study of antipsychotic prescribing decisions for acutely-Ill hospitalized patients

Background

Evidence on antipsychotic prescribing decisions is limited. This pilot study quantified factors considered in choosing an antipsychotic and evaluated the influence of metabolic status on treatment decisions.

Methods

Prescribing decisions by 4 psychiatrists were examined based on 80 adult patients initiated on antipsychotic medication diagnosed with schizophrenia, schizoaffective disorder or bipolar disorder by DSM-IV criteria, who were admitted to an acute inpatient psychiatric program of an urban Veterans Affairs Medical Center. The primary analysis examined the association between antipsychotic treatment choice and predictions of symptom control and metabolic risk. Secondary analyses included comparison of the chosen and next best treatments in predicted symptom control and metabolic risk, the frequency of reasons cited for drug choice, and the association between treatment choice and patients' baseline metabolic parameters. Mean differences and odds-ratios (OR) with 95% confidence intervals were used to compare relationships between treatment choice, ratings of risk and metabolic data.

Results

Antipsychotic choice correlated significantly with ratings of predicted symptom control (OR = .92, p = 0.02) and metabolic risk (OR = .88, p = 0.01). Mean differences between the chosen and next best drugs were significant but small in predicted symptom control (F = 2.81, df = 3, 76; p < 0.05) compared with larger differences in anticipated metabolic risk (F = 14.80, df = 3, 76; p = 0.0001). Nevertheless, among 24 identified reasons influencing drug selection, anticipated metabolic risk of chosen antipsychotics was cited less often than efficacy measures. In contrast to psychiatrists' expectations of metabolic risk with selected treatments, we found that patients' actual baseline BMI, fasting glucose, blood pressure, and Framingham risk levels did not necessarily predict antipsychotic treatment choice independent of other factors.

Conclusion

In the context of an acute psychiatric hospitalization, pilot data suggest that predictions of symptom control and metabolic risk correlated significantly with antipsychotic choice, but study psychiatrists were willing to assume relative degrees of metabolic risk in favor of effective symptom control. However, prescribing decisions were influenced by numerous patient and treatment factors. These findings support the potential utility of the ATCQ questionnaire in quantifying antipsychotic prescribing decisions. Further validation studies of the ATCQ questionnaire could enhance translation of research findings and application of treatment guidelines.     

The loudness dependence of the auditory evoked potential (LDAEP) in schizophrenia,bipolar disorder,major depressive disorder,anxiety disorder,and healthy controls

Background

Serotonergic dysfunction in schizophrenia, bipolar disorder, major depressive disorder, anxiety disorder, and healthy controls was evaluated by measuring the activity of the loudness dependence of the auditory evoked potential (LDAEP).

Methods

The 357 subjects who were evaluated comprised 55 normal controls, 123 patients with major depressive disorder, 37 with bipolar disorder, 46 with schizophrenia, 37 with panic disorder (PD), 31 with generalized anxiety disorder (GAD), and 28 with post-traumatic stress disorder (PTSD).

Results

LDAEP was significantly stronger in healthy controls than in patients with either bipolar disorder (p = 0.025) or schizophrenia (p = 0.008), and significantly stronger in patients with major depressive disorder than in those with bipolar disorder (p = 0.01) or schizophrenia (p = 0.03). LDAEP did not differ significantly between patients with major depressive disorder and healthy control subjects (p = 0.667), or between healthy control subjects and patients with anxiety disorder, including PD (p = 0.469), GAD (p = 0.664), and PTSD (p = 0.167).

Conclusion

The findings of the present study reveal that patients with major psychiatric disorders exhibit different strengths of LDAEP according to their serotonin-related pathology. Studies controlled for psychotropic medication, menstruation cycle, and smoking are needed.     

Impaired sustained attention and executive dysfunction: Bipolar disorder versus depression-specific markers of affective disorders

Objective

To identify neurocognitive measures that could be used as objective markers of bipolar disorder.

Methods

We examined executive function, sustained attention and short-term memory as neurocognitive domains in 18 participants with bipolar disorder in euthymic state (Beuth), 14 in depressed state (Bdep), 20 with unipolar depression (Udep) and 28 healthy control participants (HC). We conducted four-group comparisons followed by relevant post hoc analyses.

Results

Udep and Bdep, but not Beuth showed impaired executive function (p = 0.045 and p = 0.046, respectively). Both Bdep and Beuth, but not Udep, showed impaired sustained attention (p = 0.001 and p = 0.045, respectively). The four groups did not differ significantly on short-term memory. Impaired sustained attention and executive dysfunction were not associated with depression severity, duration of illness and age of illness onset. Only a small number of abnormal neurocognitive measures were associated with medication in Bdep and Beuth.

Conclusion

Impaired sustained attention appears specific to bipolar disorder and present in both Beuth and Bdep; it may represent an objective marker of bipolar disorder. Executive dysfunction by contrast, appears to be present in Udep and Bdep and likely represents a marker of depression.     

Decreased serum BDNF levels in major depressive patients

Background

Brain-derived neurotrophic factor (BDNF) plays an important role in neuronal plasticity. The aim of the present study was to measure serum BDNF levels in depression and to analyze the relationship between BDNF levels and severity of depression.

Methods

Thirty patients meeting the DSM-IV criteria for major depressive disorder and 40 normal control subjects were recruited for this study. Patients had not used psychotropic drugs. The severity of depression was assessed by the Hamilton Rating of Depression Scale (HAM-D). Serum BDNF levels were determined by using ELISA.

Results

HAM-D scores were 17.09 ± 4.96 in depressed patients. We determined that the serum BDNF levels of the depression patients were lower than those of the healthy control group (respectively, 1453.42 ± 144.51 pg/ml, 1632.23 ± 252.93 pg/ml, t = 3.467, p = 0.001, independent t test). No correlation was found between the patients’ serum BDNF levels and HAM-D scores (p > 0.05, Pearson correlation analysis).

Conclusions

Our results suggest that serum BDNF levels are low in depression. However it was not found association between serum BDNF levels and the severity of depression.     

Sunshine-exposure variation of human striatal dopamine D2/D3 receptor availability in healthy volunteers

Background

In addition to the serotonergic system, the central dopaminergic system has been reported to be correlated with seasonality. The aim of this study was to explore the difference in striatal dopamine D₂/D₃ receptor availability between healthy volunteers who had a high-sunshine exposure and those who had a low exposure.

Methods

Sixty-eight participants were enrolled, and those in the upper and lower quartiles in terms of sunshine exposure were categorized into high- (n = 17) and low-sunshine-exposure (n = 18) subgroups. Single photon emission computed tomography with [¹²³I] iodo-benzamide was used to measure striatal dopamine D₂/D₃ receptor availability.

Results

Striatal dopamine D₂/D₃ receptor availability was significantly greater in the subjects with high-sunshine exposure than in those with low-sunshine exposure (F = 7.97, p = 0.01) after controlling for age, sex, and smoking status.

Limitations

Different subjects were examined at different time points in our study. In addition, the sex and tobacco use distributions differed between groups.

Conclusion

The central dopaminergic system may play a role in the neurobiological characteristics of sunshine-exposure variation.     

Antipsychotic dose and diminished neural modulation: a multi-site fMRI study

Background

The effect of antipsychotics on the blood oxygen level dependent signal in schizophrenia is poorly understood. The purpose of the present investigation is to examine the effect of antipsychotic medication on independent neural networks during a motor task in a large, multi-site functional magnetic resonance imaging investigation.

Methods

Seventy-nine medicated patients with schizophrenia and 114 comparison subjects from the Mind Clinical Imaging Consortium database completed a paced, auditory motor task during functional magnetic resonance imaging (fMRI). Independent component analysis identified temporally cohesive but spatially distributed neural networks. The independent component analysis time course was regressed with a model time course of the experimental design. The resulting beta weights were evaluated for group comparisons and correlations with chlorpromazine equivalents.

Results

Group differences between patients and comparison subjects were evident in the cortical and subcortical motor networks, default mode networks, and attentional networks. The chlorpromazine equivalents correlated with the unimotor/bitemporal (rho = − 0.32, P = 0.0039), motor/caudate (rho = − 0.22, P = 0.046), posterior default mode (rho = 0.26, P = 0.020), and anterior default mode networks (rho = 0.24, P = 0.03). Patients on typical antipsychotics also had less positive modulation of the motor/caudate network relative to patients on atypical antipsychotics (t₇₇ = 2.01, P = 0.048).

Conclusion

The results suggest that antipsychotic dose diminishes neural activation in motor (cortical and subcortical) and default mode networks in patients with schizophrenia. The higher potency, typical antipsychotics also diminish positive modulation in subcortical motor networks. Antipsychotics may be a potential confound limiting interpretation of fMRI studies on the disease process in medicated patients with schizophrenia.     

Undiagnosed depression and its correlates in a predominantly immigrant Hispanic neurology clinic

Objective

Previous studies have reported a high incidence of depression in neurology clinics, however areas where there are predominantly underserved immigrants have not been studied.

Methods

Retrospective cohort study in an academic outpatient neurology clinic in Los Angeles, California. Newly referred patients (N = 318) were assessed consecutively for depression using a PHQ-9 questionnaire, accompanied by review of the assessment of the depressive disorder.

Results

The patient cohort consisted of 190 females (59%) and 130 males (41%), primarily of Hispanic descent (72%), with 8% Asian 11% white, and 5% African-American. Sixty-eight percent (68%) had depression, with 40% exhibiting moderate to severe depression. Patients who had moderate to severe depression (based on PHQ-9) were more likely to be unemployed (75.2% vs. 60.7%, p = 0.008), dependent on government income (29.5% vs. 20.4%, p = 0.06), and have headache or pain as the reason for referral (42.4% vs. 28.5%, p = 0.03). Severity of depression also significantly correlated with current treatment by psychiatrist, current antidepressant use, and less independent living. Patients with moderate to severe depression were more likely to have made ER visits in the last 12 months (0.9 vs. 0.7, p = 0.01) and were taking more medications (3.3 vs. 2.5, p = 0.03), compared to patient with mild or no depression.

Conclusion

The presence of moderate to severe depression significantly correlated with socioeconomic status, use of emergency room, and presence of headache/pain. Neurology clinics with predominantly underserved immigrant patients have a disproportionate amount of depression, which may be related to socioeconomic factors resulting in overutilization of scarce healthcare resources.