The effect of chronic antidepressant treatment on serum brain-derived neurotrophic factor levels in depressed patients: a preliminary study

Recent studies suggested a role of brain-derived neurotrophic factor (BDNF) in depression. While BDNF levels are lower in depressed patients, antidepressant treatment increases serum BDNF levels of depressed patients. Our study aims to test the effect of chronic venlafaxine treatment on serum BDNF levels in patients with a major depressive disorder. Ten patients diagnosed as major depressive disorder according to DSM-IV are included in the study. Two of the patients had their first episode and were drug-naive, the other eight patients were drug-free for at least 4 weeks. The severity of depression was assessed with Hamilton Depression Rating Scale (HDRS). The control group consisted of ten age- and sex-matched subjects without any psychiatric disorder. Blood samples were collected at the baseline and after 12 weeks of antidepressant treatment (during remission). At the baseline the mean serum BDNF level was 17.9+/-9.1 ng/ml and the mean HDRS score was 23.2+/-4.6. Serum BDNF levels of the study group were significantly lower than in the control group (31.6+/-8.6 ng/ml). At the end of the study, the mean serum BDNF level was 34.6+/-7.1 ng/ml whereas the mean HDRS score was 8.2+/-3.9. From the baseline to the remission after 12 weeks of treatment, the increase in serum BDNF level and the decrease in HDRS score were statistically significant, respectively. When we compared the serum BDNF level of depressed patients at remission to that of the controls, there was no statistically significant difference. This study shows that venlafaxine treatment of depression improves serum BDNF level which may be considered as a nonspecific peripheral marker of depression.     

Rapid antidepressant changes with sleep deprivation in major depressive disorder are associated with changes in vascular endothelial growth factor (VEGF): a pilot study

While conventional antidepressants benefit many patients with major depressive disorder (MDD), as much as eight to 12 weeks can elapse before significant improvements in depressive symptoms are seen. Treatments that act more rapidly in MDD are urgently needed. Sleep deprivation (SD) has been shown to produce a rapid antidepressant response within one day in 50-60% of patients with MDD; thus, identifying its antidepressant mechanism may contribute to the development of antidepressants that act more rapidly. The present study evaluated the effects of 39 h of SD on mood, as well as on plasma levels of brain derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in patients with MDD. After a drug-free period of at least two weeks, 11 patients (6 males, 5 females; ages 25-62) who met DSM-IV criteria for MDD underwent total SD. Plasma samples for BDNF and VEGF assays were collected on Days 1 (baseline) and 2. The six-item Hamilton Rating Scale for Depression (HAMD-6) was the primary outcome measure. HAMD-6 scores decreased significantly after SD (Day 2). SD was negatively correlated with change in HAMD-6 score and change in VEGF levels, indicating that as depression scores decreased following SD, VEGF plasma levels increased. In contrast, SD did not alter plasma BDNF concentrations, nor was an association found between BDNF levels and clinical improvement on the HAMD-6. These results suggest that SD is associated with mood-related changes in plasma VEGF levels, but not plasma BDNF levels. Further studies using larger sample sizes are needed to confirm these preliminary findings.     

Efficacy of electroconvulsive therapy is associated with changing blood levels of homovanillic acid and brain-derived neurotrophic factor (BDNF) in refractory depressed patients: a pilot study

Electroconvulsive therapy (ECT) is effective for patients with antidepressant medication-resistant depression. However, the mechanisms of ECT's effectiveness for treating depression are not fully understood. We therefore investigated ECT's effects on blood levels of brain-derived neurotrophic factor (BDNF), catecholamine metabolites, and nitric oxide (NO) in 18 treatment-refractory depressed patients. Serum BDNF levels increased significantly following ECT in responders to ECT (before ECT: 8.0+/-9.7 ng/mL; five weeks after start of ECT: 15.1+/-11.1 ng/mL), whereas BDNF levels in non-responders were unchanged (before ECT: 11.5+/-11.0 ng/mL; five weeks after start of ECT: 9.4+/-7.5 ng/mL). Furthermore, the plasma HVA levels, but not MHPG levels, were significantly reduced after ECT (before ECT: 8.5+/-1.9 ng/mL; five weeks after start of ECT: 5.8+/-2.2 ng/mL). This latter finding occurred in parallel with the improvement of depressive symptoms in all patients. These results suggest that the mechanisms underlying ECT's effect on refractory depression may be related to dopaminergic neurons and BDNF.     

Low plasma BDNF is associated with suicidal behavior in major depression

Brain-derived neurotrophic factor (BDNF), the most abundant neurotrophin in the brain, has a known association with the pathophysiology of anxiety and depression. However, the role of BDNF in suicide has not been well investigated to date. This study examined plasma BDNF levels in 32 major depressive disorder (MDD) patients who had recently attempted suicide, 32 non-suicidal MDD patients, and 30 normal controls. The lethality of the suicide attempt was measured using the Risk-Rescue Rating (RRR) and Lethality Suicide Attempt Rating Scale (LSARS). The severity of depression was measured with the Hamilton Depression Rating Scale (HDRS). Plasma BDNF levels were measured by enzyme linked immunosorbent assay. BDNF levels were significantly lower in suicidal MDD patients (430.5+/-397.0 pg/ml) than non-suicidal MDD patients (875.80+/-663.02 pg/ml) or normal controls (889.4+/-611.3 pg/ml) (F=6.682, p=0.002). The most suitable cut-off point of BDNF level between suicidal depression and non-suicidal depression groups was 444.58 pg/ml. At this cut-off point, the sensitivity=68.7%, specificity=78.1%, positive predictive value=75.9%, and negative predictive value=71.4%. However, there was no significant difference in BDNF levels between the depressive control and normal control groups (p=0.996). LSARS and RRR did not reveal any significant correlations with BDNF levels in suicidal patients. In addition, BDNF levels were not different between fatal and non-fatal suicide attempts. These results suggest that reduction of plasma BDNF level is related to suicidal behavior in major depression and that BDNF level may be a biological marker of suicidal depression.     

Changes in BDNF serum levels in patients with major depression disorder (MDD) after 6 months treatment with sertraline, escitalopram, or venlafaxine

Recent studies have implicated brain-derived neurotrophic factor (BDNF) in the pathophysiology of depression and the activity of antidepressant drugs. Serum BDNF levels are lower in depressed patients, and increase in response to antidepressant medication. However, how BDNF responds to different classes of antidepressant drugs is unknown. We assessed serum BDNF levels in 21 patients with major depressive episode treated with sertraline, escitalopram, or venlafaxine and 20 healthy controls. Serum samples were collected between 10 a.m. and 12 p.m. at baseline, 5 weeks, and 6 months of treatment. BDNF levels were measured via immunoassay. The severity of symptoms and response to treatment were assessed by the Hamilton rating scales for depression (HRSD). Baseline serum BDNF levels were significantly lower in depressed patients compared to controls. Sertraline increased BDNF levels after 5 weeks and 6 months of treatment. Venlafaxine increased BDNF levels only after 6 months. Escitalopram did not affect BDNF levels at either time point. A significant negative association was found between percentage increase in BDNF levels and percentage decreased in HRSD scores after 6 months of treatment. In conclusion, these results suggest that different antidepressant drugs have variable effects on serum BDNF levels. This is true even though the three different drugs were equally effective in relieving symptoms of depression and anxiety.     

抑郁症患者治疗前后血清脑源性神经营养因子水平变化及相关因素分析

目的 探讨抑郁症患者血清脑源性神经营养因子(BDNF)水平及其变化与负性生活事件、抑郁症发病及治疗效应的关系.方法 采用横断面的病例-对照及前瞻性自身对照设计.对所有抑郁症患者给予抗抑郁治疗(包括抗抑郁药和改良电抽搐治疗),并随访治疗8周;采用酶联免疫吸附法测定63例抑郁症患者(抑郁症组)治疗前和治疗第2,4,8周末及80名正常对照(以下简称对照组)血清BDNF水平,并评定汉密尔顿抑郁量表(HAMD)和生活事件量表.结果 抑郁症组治疗前血清BDNF水平[(24±14)μg/L]显著低于对照组[(36±15)μg/L](t=-4.863,P=0.000),并与病前1年负性生活事件刺激值、治疗前HAMD总分均显著负相关(r=-0.331,P=0.008;r=-0.343,P=0.006),而后两者有相互正相关(r=0.292,P=0.020);治疗第2周末血清BDNF水平仍显著低于对照绢(t=-5.990,P=0.000),并与其抑郁症状严重度平行负相关(r=-0.269,P=0.033),且其血清BDNF增加率与HAMD减分率平行正相关(r=0.252,P=0.047);治疗第4,8周末血清BDNF水平均显著高于治疗前(经ISD检验,P=0.000;P=0.005),与对照组的差异均无统计学意义(P均＞0.05).治疗第2,4,8周末HAMD总分渐减并均低于治疗前(P均=0.001),且其HAMD平均减分率渐升(分别为40%,66%和74%).结论血清BDNF低下与负性生活事件、抑郁症发病密切相关,血清BDNF升高可能为抗抑郁治疗临床疗效的重要指标之一.     

Effects of fluoxetine and venlafaxine on serum brain derived neurotrophic factor levels in depressed patients

Background

Several studies demonstrated that depressed patients had low serum BDNF levels which correlated with the severity of their depression, and antidepressant treatment increases levels of serum BDNF in depressed patients. It was speculated that agents acting on both noradrenergic and serotonergic transporters might have a greater influence on BDNF levels. The aim of our study was to determine effects of venlafaxine vs. fluoxetine on serum BDNF levels in depressive patients.

Methods

Forty-three patients diagnosed as major depressive disorder according to DSM-IV are included in the study. Forty-three patients were randomized to take fluoxetine (22 cases) or venlafaxine (21 cases). Serum levels of BDNF were measured by ELISA at baseline and 6 weeks after the start of treatment.

Results

Baseline levels of BDNF were not significantly different between the patient group and the controls. But male patients and the male controls showed statistical differences with respect to baseline BDNF levels. BDNF levels of the patient group did not change with treatment. Yet, the increase of BDNF levels was close to statistically significant in the fluoxetine group, whereas not significant in the venlafaxine group. There were no significant differences in baseline and 6th week BDNF levels between the responders and the non-responders.

Conclusion

Further studies controlling for a wide variety of confounding variables are needed, which may help to reach a clear conclusion about the potential of BDNF as a biomarker for depression or as a predictor of antidepressant efficacy.     

Serum BDNF levels in suicide attempters related to psychosocial stressors: a comparative study with depression

Although many studies have examined the neurobiological aspects of suicide, the molecular mechanisms and pathophysiologic mechanisms associated with suicide remain unclear. In this study, it is aimed to investigate whether there is a difference in serum brain-derived neurotrophic factor (BDNF) levels among suicide attempters without a major psychiatric disorder, compared to major depressive disorder patients and healthy subjects. It was undertaken with the hypothesis that suicide per se lowers serum BDNF levels, since it is a source of stress. The study was carried out in Celal Bayar University Hospital, Manisa, Turkey. Ten suicide attempters, 24 patients with major depressive disorder and 26 subjects without any psychiatric diagnosis and any psychiatric treatment were included in the study. All subjects were asked to give their written consent. Blood samples were collected at the baseline. Serum BDNF was kept at -70 degrees C before testing, and assayed with an ELISA kit (Promega; Madison, Wisc., USA) after dilution with the block and sample solution provided with the kit. The data were subjected to the Kruskal-Wallis test for nonparametric analysis of variance. Mean serum BDNF levels were significantly lower in the suicide group (21.2 +/- 12.4 ng/ml) and the major depressive disorder group (21.2 +/- 11.3 ng/ml) than the control group (31.4 +/- 8.8 ng/ml; p = 0.004). These results suggest that BDNF may play an important role in the neurobiology of suicidal behavior. BDNF levels may be a biological marker for suicidal behavior. To investigate the role of BDNF in suicide, further studies with a wider sample size and a variety of psychiatric diagnoses accompanying suicide attempt are needed.     

No change between the serum brain-derived neurotrophic factor in female patients with anorexia nervosa before and after partial weight recovery

BACKGROUND: Brain-derived neurotrophic factor (BDNF) is a member of the nerve growth factor family. Several lines of evidence indicate that BDNF plays a role in the pathophysiology of eating disorders (ED). We found that serum BDNF levels in patients with ED were significantly lower than in normal controls. The aim of this longitudinal study was to compare serum BDNF levels in patients with anorexia nervosa (AN) before (n=13, initial mean body mass index (BMI)=14.2 kg/m(2)+/-0.7) and after partial recovery (mean BMI=16.2 kg/m(2)+/-1.7, mean weight gain 5.0 kg+/-2.0), with age-matched normal control subjects (n=17, mean BMI=20.4 kg/m(2)+/-1.5). METHODS: Eating related psychopathology and depressive symptoms were evaluated before and after partial weight recovery, using the Eating Disorder Inventory-2 (EDI-2) and the 17-item Hamilton Depression Rating Scale (HDRS). Serum BDNF levels were measured using a sandwich enzyme-linked immunosorbent assay. RESULTS: Serum BDNF levels with the AN patients (14.5+/-4.4 ng/ml) were significantly (p<0.01) lower than in control subjects (22.1+/-8.9 ng/ml). There were no significant differences in serum BDNF levels between the patients with AN before (14.5+/-4.4 ng/ml) and after (17.2+/-6.9 ng/ml) partial weight recovery. In all subjects, there was a positive correlation (r=0.5, p<0.01) between the baseline BDNF levels and the EDI-2 scores (n=30). Furthermore, in all subjects there was a positive correlation (r=0.4, p<0.05) between the BDNF levels and the BMI. CONCLUSIONS: Serum BDNF levels did not change after partial weight recovery in AN patients. Our results suggest that an alteration of the serum BDNF in AN patients is not due to changes in body weight. Thus, other possible mechanisms that could be related to low serum BDNF levels in AN patients should be evaluated.     

High-frequency repetitive transcranial magnetic stimulation improves refractory depression by influencing catecholamine and brain-derived neurotrophic factors

INTRODUCTION: Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive and easily tolerated method of altering cortical physiology. To date, numerous open and sham controlled clinical trials have explored the antidepressant potential of rTMS. In the present study, we investigated clinical trials of high-frequency rTMS (20 Hz) for treatment of refractory depression, and also examined the effect of rTMS on plasma levels of catecholamine metabolites and brain-derived neurotropic factor (BDNF). METHODS: Twenty-six depressed inpatients who met the DSM-IV criteria for major depressive disorder and had failed to respond to treatment with at least two antidepressant drugs given at adequate doses (above 150 mg/day in an equivalent dose of imipramine) and durations (at least 4 weeks for each drug) were enrolled in this study. Eleven were males, 15 females. The ages of the subjects ranged from 19 to 78 years old (mean +/- SD = 52.9 +/- 17.8). All patients were administered left prefrontal 20 Hz rTMS at 80 % MT (total 800 pulses a day) over ten daily sessions. The plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were analyzed by high-performance liquid chromatography. The plasma levels of BDNF were also measured with the sandwich ELISA method. RESULTS: The mean 17-item Hamilton Rating Scale for Depression (Ham-D) score of 20.5 +/- 5.2 before rTMS was significantly decreased to 15.6 +/- 7.3 after rTMS. Nine of 26 patients (35 %) demonstrated some improvement (Ham-D > or = 25 %) by rTMS. The levels of plasma MHPG, but not those of HVA, were significantly reduced after rTMS treatment, and a negative correlation was observed between the change in plasma MHPG levels and the change in scores of agitation. In addition, the plasma levels of BDNF were significantly increased by 23 % in responders and partial responders, but not in nonresponders, after rTMS treatment, and a trend for association was found between the changes in Ham-D scores and changes in plasma BDNF levels in all patients after rTMS treatment. CONCLUSION: These results suggest that rTMS treatment brings about some improvement in refractory depression, especially for symptoms such as agitation, by influencing MHPG and BDNF, which is in accordance with previous reports showing that BDNF was increased by various antidepressants treatments.     

Serum brain-derived neurotrophic factor level in dysthymia: a comparative study with major depressive disorder

In this present work, it is aimed to demonstrate BDNF serum concentrations in patients with dysthymia and to compare them with BDNF serum concentrations in patients with major depressive disorder and healthy subjects. The study was carried out in Celal Bayar University Hospital, Manisa, Turkey. Seventeen patients with dysthymia, 24 patients with major depressive disorder and 26 subjects without any psychiatric diagnosis and any psychiatric treatment were included in the study. The severity of depression was assessed with 17-item HAM-D. All subjects were asked to give their written consent. Blood samples were collected at baseline. Serum BDNF was kept at -70 degrees C before testing, and assayed with an ELISA Kit (Promega; Madison, WI, USA), after dilution with the Block and Sample solution provided with the kit. The data were subjected to the analysis of variance. The BDNF serum concentrations of the dysthymia group (mean=28.9+/-9.2 ng/ml) were significantly higher than that of the major depressive disorder group (21.2+/-11.3 ng/ml) (p=0.002), and it was not different from the level of the control group (31.4+/-8.8 ng/ml). BDNF serum concentrations and HAM-D score did not have any significant correlation in the dysthymia and major depression groups (r=-0.276, p=0.086). The low level of BDNF in patients with dysthymic disorder seems to point out that BDNF changes in mood disorders are state-dependent and vary according to the severity of depressive episodes.     

Reduced plasma norepinephrine response to standing in autonomic dysfunction.

In five patients having primary autonomic dysfunction with clinical manifestations including postural hypotension, the mean plasma norepinephrine concentrations were significantly lower than those of normal subjects after two and five minutes in the standing position. The mean (+/-SE) increment in the plasma norepinephrine concentration after two minutes standing were 123 +/- 19 pg/ml in the normal subjects and 13 +/- 4 pg/ml (P less than .001) in the patients with primary autonomic dysfunction. After five minutes standing, the mean increment in plasma norepinephrine concentration was 244 +/- 36 pg/ml in the normal subjects and 99 +/- 51 pg/ml (P less than .05) in the patients. There were no statistically significant differences in plasma epinephrine between the two groups.     

Plasma BDNF and tPA are associated with late‐onset geriatric depression

Aims: Studies in the recent decade have shown that brain‐derived neurotrophic factor (BDNF) may play an important role in the pathogenesis of major depressive disorder (MDD). Tissue‐type plasminogen activator (tPA) has been implicated in the control of the direction of BDNF action. The aim of the study was therefore to investigate the changes of BDNF/tPA levels and their clinical meanings in geriatric depression. Methods: Plasma BDNF and tPA levels were measured in late‐onset geriatric depression (LGD) before treatment (n = 24) and after 6 weeks of antidepressant treatment (n = 24) compared with control subjects (n = 30) using enzyme‐linked immunosorbent assay. The severity of depression was assessed with the Hamilton Depression Rating Scale. Results: Baseline plasma BDNF and tPA levels were significantly lower in LGD patients compared to controls (P = 0.037 and P = 0.000, respectively). There was a heightening tendency of plasma BDNF level after treatment. Conclusions: Plasma BDNF and tPA levels are associated with LGD. The complex mechanism of BDNF and tPA in LGD should be further explored in future studies.     

Botulism: heart rate variation, sympathetic skin responses, and plasma norepinephrine.

BACKGROUND: Botulism may involve the autonomic nervous system. METHODS: We assessed the autonomic function of 6 botulism patients with heart rate variations, sympathetic skin responses, and plasma norepinephrine. RESULTS: Two weeks after onset, all the patients had absent sympathetic skin response in the palm and sole. Compared with controls, the heart rate variation of botulism patients was significantly decreased at rest (3.1 +/- 1.2% vs. 20.9 +/- 2.0%, p = 0.0018) and during deep breathing (4.3 +/- 2.3% vs. 29.7 +/- 2.6%, p = 0.0018). The botulism patients had significantly lower plasma norepinephrine levels (supine 29.2 +/- 10.1 pg/ml vs. 257.5 +/- 65.8 pg/ml, p = 0.0018; standing 40.3 +/- 13.1 pg/ml vs. 498.5 +/- 85.6 pg/ml, p = 0.0018). The heart rate variation and sympathetic skin response was greatly improved 6 months after onset. CONCLUSIONS: Heart rate variation, absence of sympathetic skin response, and low plasma norepinephrine are all manifestations of autonomic dysfunction in botulism patients.     

Adding a low dose atypical antipsychotic drug to an antidepressant induced a rapid increase of plasma brain-derived neurotrophic factor levels in patients with treatment-resistant depression

Only two-thirds of depressive patients respond to antidepressant treatment. Recently, addition of an atypical antipsychotic drug to ongoing treatment with an antidepressant has been considered effective and well-tolerated. In the present study, we examined the effects of various atypical antipsychotic drugs as adjuvant to antidepressants, including selective serotonin reuptake inhibitors (SSRIs), serotonin noradrenaline reuptake inhibitors, tricyclic antidepressants and mood stabilizers, on plasma BDNF levels in refractory depressed patients. Forty-five patients who met the DSM-IV criteria for major depressive disorder (n = 31) or bipolar disorder (10 with bipolar I, 4 with bipolar II) were enrolled in the study. Twenty-one were male and 24 were female, and their ages ranged from 28 to 71 (mean ± SD = 49 ± 12) years. Plasma BDNF levels were measured using a sandwich ELISA. The plasma BDNF levels in responders (those showing a decline in HAM-D scores of 50% or more) were significantly increased 4 weeks after the administration of each atypical antipsychotic drug, while the levels in non-responders were not changed. Furthermore, there was a significant correlation between the changes in HAM-D scores and the changes in plasma BDNF levels. These results suggest that adding an atypical antipsychotic drug to ongoing treatment with an antidepressant or mood stabilizer is useful and well-tolerated for refractory depressed patients, and the efficacy of atypical antipsychotics as an adjuvant might involve an increase of plasma BDNF levels.     

Effect of clomipramine and lithium on fenfluramine-induced hormone release in major depression.

Prolactin (PRL) and cortisol responses to oral administration of d-1 fenfluramine hydrochloride (60 mg) and placebo were examined in patients with endogenous major depressive disorder on three separate occasions: prior to treatment with clomipramine (CMI), after 4 weeks of CMI administration (175-250) mg/day), and 3 weeks after addition of lithium (Li) carbonate (serum level 0.5-0.9 mmol) to the treatment regimen. CMI significantly increased baseline PRL levels which were further elevated following Li supplementation. PRL response to fenfluramine (minus elevated baseline PRL levels) but not to placebo, was significantly increased by CMI administration, reflected over the 6-hr time course examined and in peak minus baseline values. Following addition of Li, the degree of enhancement was diminished although the peak minus baseline value remained significant relative to the pretreatment response. Cortisol levels were not increased by fenfluramine and were not altered by CMI or CMI + Li administration. The effect of CMI extends previous observations regarding the action of antidepressant treatment on serotenergically mediated hormone release. Methodological considerations relevant to the effect of CMI + Li are discussed.     

Vascular endothelial growth factor: Potential predictor of treatment response in major depression

Objectives: The aim of the study was to evaluate baseline plasma VEGF levels as a potential predictor of response to antidepressant pharmacotherapy. The study also sought to determine whether baseline plasma VEGF would be useful in predicting treatment outcome when two pharmacodynamically diverse agents with established antidepressant efficacy, escitalopram and quetiapine, were administered monotherapeutically to MDD patients. Methods: Two groups of qualifying MDD subjects were enrolled. One group was treated with escitalopram and the other with quetiapine. Plasma concentrations of VEGF were measured using Randox Technologies at baseline, and at weeks 8 and 12 of treatment. Results: We stratified the MDD patients into those who remitted and those who failed to respond. Mean baseline VEGF for the remitters and non-responders was 9.61 and 5.40?pg/ml, respectively (P?Conclusions: Our results suggest that VEGF may predict response to antidepressant treatment and may ultimately prove to be a potential biomarker that can be measured with a routine blood draw at the point of service.     

Brain derived neurotropic factor in first-episode psychosis

There is much interest, derived from current neurochemical, genetic, and therapeutic research, in the role of brain neurotrophins in schizophrenia. Neurotrophins play key roles in neuronal development and differentiation (i.e., promoting dendritogenesis and synaptogenesis), and in orchestrating the neuronal response to stress/noxious stimuli. Additionally, neurotrophins are modulators across monominergic (dopamine and serotonin), gabaergic and cholinergic systems. These roles focus on important areas of the etiopathophysiology of schizophrenia. Clinical studies show reductions in brain-derived neurotrophic factor (BDNF) and nerve growth factor (NFG) in schizophrenic patients as compared to normal control subjects, as well as differences in patients receiving first-generation antipsychotics (FGAs) or second-generation antipsychotics (SGAs). We now report on BDNF levels in subjects with first-episode psychosis in comparison with normal healthy controls. Compared to normal controls (N=14; 290.5+/-38.81 pg/ml), first-episode psychotic patients showed significant reduction (N=15; 135+/-21.77 pg/ml; P=0.001; f=12.873) in plasma BDNF. Additionally, plasma BDNF levels showed a significant negative correlation (N=13' r=0.584, P=0.0362) only with positive symptom scores at base line and no significant correlations were found with any of the cognitive performance test battery or motor function test scores. Low BDNF levels at the onset of psychosis suggest that it may contribute to the pathogenesis of schizophrenia and/or perhaps could be a helpful neurobiological marker for possible early treatment intervention.     

Comparative pharmacokinetic study of conventional and sustained-release viloxazine in normal volunteers

Animal and human studies have indicated that viloxazine hydrochloride, an antidepressant drug with a half-life of 3-4 h in most subjects at low dosage, is rapidly and almost completely absorbed after oral administration. A sustained-release form might be useful to decrease the frequency of administration. In our study, the pharmacokinetics of sustained-release form containing 300 mg viloxazine were compared with 300 mg conventional viloxazine in 11 normal volunteers (6 women, 5 men). Wide interindividual variations were observed with respect to plasma levels, but there was no significant statistical correlation between weight and blood concentration (conventional form: Cmax = 3,599 +/- 579 ng/ml, tmax = 86 +/- 26 min; sustained-release form: Cmax = 1,917 +/- 922 ng/ml, tmax = 215 +/- 77 min). Twelve hours after administration, plasma levels ranged between 540 and 1,600 ng/ml for the conventional form and between 660 and 2,120 ng/ml for the sustained-release form. Despite the great interindividual variation this new viloxazine form appears to be of interest for one daily administration.