Jean-Michel Aubry

Decreased serum brain-derived neurotrophic factor levels in major depressed patients.

Recent findings with animal models have suggested a possible role for brain-derived neurotrophic factor (BDNF) in depression. We have therefore hypothesized that depression could be characterized by low levels of serum BDNF. Major depressed patients (15F + 15M) diagnosed according to DSM-IV criteria and healthy controls (15F + 15M) participated in the study. Serum BDNF was assayed with the ELISA method and the severity of depression was evaluated with Montgomery-Asberg-Depression Rating Scale (MADRS). BDNF levels were significantly lower in patients than in controls: 22.6 +/- 3 and 26.5 +/- 7 ng/ml (t-test = 2.7; d.f. = 58; P < 0.01). They were negatively correlated to the MADRS scores (r = -0.55; P < 0.02). Female patients were more depressed and released less BDNF than men. Analysis of covariance (MADRS and gender as independent variable vs. BDNF as dependent variable) indicated that depression severity mainly accounted for the negative correlation. These results suggest that major depression is characterized by low serum BDNF levels and support the hypothesis of neurotrophic factor involvement in affective disorders.

Low brain-derived neurotrophic factor (BDNF) levels in serum of depressed patients probably results from lowered platelet BDNF release unrelated to platelet reactivity.

BACKGROUND Recent reports have suggested a role for brain-derived neurotrophic factor (BDNF) in psychiatric disorders. Decreased serum BDNF levels have been reported in major depression, but the cause of this decrease has not yet been investigated. The goal of this study was to assess blood BDNF and a platelet activation index, PF4. METHODS Forty-three drug-free patients (27 female, 16 male) diagnosed with major depression and 35 healthy control subjects (18 female, 17 male) were assessed for plasma, serum, and blood BDNF content. Brain-derived neurotrophic factor and PF4 were assayed with enzyme-linked immunosorbent assay methods, and severity of depression was evaluated with the Montgomery-Asberg Depression Rating Scale. RESULTS Serum and plasma BDNF levels were decreased in depressed patients compared with control subjects. In whole blood, BDNF levels were unaltered in the depressed subjects compared with control subjects. The serum/blood BDNF ratio was lower in patients with major depression. Increased plasma but not serum PF4 levels were observed in depressed subjects compared with control subjects. CONCLUSIONS Our results suggest that an alteration of serum or plasma BDNF is not due to the change in blood BDNF but rather is probably related to mechanisms of BDNF release. Secretion of BDNF seems to be independent of platelet reactivity; other mechanisms are therefore probably involved and need to be elucidated.

Partial normalization of serum brain-derived neurotrophic factor in remitted patients after a major depressive episode.

We had previously reported decreased serum brain-derived neurotrophic factor (BDNF) levels in depressed patients. In the present study, we tested the hypothesis that antidepressant treatment would normalize serum BDNF levels, at least in a subgroup of patients. Major depressed patients (15 females and 11 males) diagnosed according to DSM-IV criteria and healthy controls (13 females and 13 males) participated in this study. Serum BDNF was assayed with the ELISA method for depressed and remitted patients and the severity of depression was evaluated with the Montgomery-Asberg Depression Rating Scale. An analysis of variance showed that treatment had an effect [F(1, 24) = 4.46, p = 0.045] on the normalization of serum BDNF levels. We also found a correlation between the severity of depression (r = 0.51, p = 0.008), the pretreatment BDNF levels (r = 0.62, p = 0.001) and the difference in serum BDNF levels after antidepressant treatment. These results suggest that antidepressant treatment has a positive effect on serum BDNF levels and support the hypothesis of neurotrophic factor involvement in affective disorders.

Stress-induced changes in messenger RNA levels of N-methyl-d-aspartate and AMPA receptor subunits in selected regions of the rat hippocampus and hypothalamus

The postsynaptic AMPA/kainate and N-methyl-D-aspartate-selective glutamate receptors are formed by several different subunits and the overall subunit composition of the receptor appears to determine its physiological and pharmacological properties. Although glutamatergic mechanisms have been implicated in various forms of hippocampal stress responses, the impact of stress on glutamate receptor subunit composition has not yet been elucidated. We have used cell-by-cell quantitative in situ hybridization to assess stress-induced changes in transcript levels of N-methyl-D-aspartate and AMPA receptor subunit genes in subdivisions of the rat hippocampus and hypothalamus that are implicated in the stress response. We found that 24 h after a single immobilization stress there was a significant increase in the cellular level of NR1 subunit messenger RNA (about 35-45% above control values) in hippocampal CA3 and CA1 pyramidal cells as well as in neurons of the hypothalamic supraoptic and paraventricular nuclei. Moreover, in the CA3 area we have detected a concomitant increase (50% above controls) in the level of NR2B subunit messenger RNA, while the expression of NR2A subunit gene did not change after stress. Stress induced a selective decrease in the level of AMPA receptor subunit glutamate receptor A messenger RNA in neurons of both the CA3 and CA1 areas (18 and 24%, respectively, below control values). These results suggest that the regulation of specific subunit messenger RNAs of the N-methyl-D-aspartate and AMPA receptors may be involved in altered hippocampal and hypothalamic responsiveness to glutamate and thus could play a critical role in stress-induced changes in their function.

Depression relapse prophylaxis with Mindfulness-Based Cognitive Therapy: replication and extension in the Swiss health care system.

Background Mindfulness-Based Cognitive Therapy (MBCT) is a group intervention that integrates elements of Cognitive Behavioural Therapy (CBT) with components of mindfulness training to prevent depressive relapse. The efficacy of MBCT compared to Treatment As Usual (TAU), shown in two randomized controlled trials indicates a significant decrease in 1-year relapse rates for patients with at least three past depressive episodes. The present study is the first independent replication trial comparing MBCT + TAU to TAU alone across both language and culture (Swiss health care system). Methods Sixty unmedicated patients in remission from recurrent depression (≥ 3 episodes) were randomly assigned to MBCT + TAU or TAU. Relapse rate and time to relapse were measured over a 60 week observation period. The frequency of mindfulness practices during the study was also evaluated. Results Over a 14-month prospective follow-up period, time to relapse was significantly longer with MBCT + TAU than TAU alone (median 204 and 69 days, respectively), although both groups relapsed at similar rates. Analyses of homework adherence revealed that following treatment termination, the frequency of brief and informal mindfulness practice remained unchanged over 14 months, whereas the use of longer formal meditation decreased over time. Limitations Relapse monitoring was 14 months in duration and prospective reporting of mindfulness practice would have yielded more precise frequency estimates compared to the retrospective methods we utilized. Conclusions Further studies are required to determine which patient characteristics, beyond the number of past depressive episodes, may predict differential benefits from this therapeutic approach.

Lithium: updated human knowledge using an evidence-based approach. Part III: clinical safety

Lithium use in mental diseases has changed over the years but remains a cornerstone of treatment in bipolar disorders. In two companion papers, we have reviewed existing (and especially recent) data on lithium efficacy and updated basic knowledge regarding the practical fundamentals of lithium therapy. The present paper reviews safety data on lithium available to date.Gastrointestinal pain or discomfort, diarrhoea, tremor, polyuria, nocturnal urination, weight gain, oedema, flattening of affect and exacerbation of psoriasis are typical complaints of patients receiving long-term lithium therapy. Renal involvement results in a reduced urinary concentrating capacity, expressed as obligate polyuria, with secondary thirst. With long-term therapy, this may result in nephrogenic diabetes insipidus. In addition, glomerular filtration rate falls slightly in about 20% of patients. The view that only a few patients receiving long-term lithium are at increased risk of glomerular impairment and progressive renal insufficiency should be regarded with caution. The risk is increased in case of concomitant diseases or medications.Lithium treatment may inhibit thyroid hormone release and induce goitre. Consequently, the prevalence of both overt and subclinical hypothyroidism is increased, with circulating thyroid auto-antibodies frequently being found. Much less commonly, thyrotoxicosis may also develop in association with lithium therapy.Long-term lithium treatment may also be associated with persistent hyperparathyroidism and hypercalcaemia, as well as with hypermagnesaemia. Overweight of up to 4–10 kg is found in approximately 30% of lithium-treated patients.Most neurological manifestations are benign, for example, the fine postural and/or action tremor present in 4–20% of patients. This is increased by high caffeine consumption and concomitant use of other psychotropic agents. A number of rare, potentially serious neurological adverse effects have been reported, including extrapyramidal symptoms, ‘pseudotumour cerebri’ or occasionally cerebellar symptoms. Severe neurological sequelae are exceptional.Cognitive disturbances are often mentioned as a lithium-related adverse effect. The few controlled studies do show a statistically significant negative effect of lithium on memory, vigilance, reaction time and tracking. There are frequent reports of mild effects of lithium on cognition at therapeutic serum concentrations.A number of deaths associated with lithium treatment have been reported. The most serious issue is that of non-accidental overdose, i.e. either long-term overdosage or acute overdose on long-term treatment. Progressive renal insufficiency, an exceptional complication of long-term lithium therapy, may also have a fatal outcome.In relation to pregnancy, lithium salts are rated as category D (positive evidence of risk). Therefore, prescription of lithium should be avoided during the first trimester of pregnancy unless the benefit to the mother exceeds the risk to the fetus.Although lithium transfer into breast milk is well established, the long-term fate of babies breast-fed by mothers receiving lithium therapy is unknown. Whether lithium therapy is safe in breast-feeding women is controversial. Although there is no absolute contraindication, it is known that the kidney is particularly sensitive to lithium just after birth.Intoxication in patients on long-term treatment with lithium in the absence of history of acute ingestion is not rare. Contributing factors include change in daily dose, long-term high dosage, kidney disease or drug interaction. In suspected cases, serum concentrations should be obtained early and repeatedly. In addition to supportive measures, haemodialysis is the treatment of choice for severe cases.Thorough knowledge of the limitations and drawbacks of lithium therapy is mandatory for its optimal use, especially at a time when its risk/benefit profile needs to be compared accurately with that of antiepileptic drugs and other mood stabilizing medications.

Lithium: Updated Human Knowledge Using an Evidence-Based Approach Part II: Clinical Pharmacology and Therapeutic Monitoring

After a single dose, lithium, usually given as carbonate, reaches a peak plasma concentration at 1.0–2.0 hours for standard-release dosage forms, and 4–5 hours for sustained-release forms. Its bioavailability is 80–100%, its total clearance 10–40 mL/min and its elimination half-life is 18–36 hours. Use of the sustained-release formulation results in 30–50% reductions in peak plasma concentrations without major changes in the area under the plasma concentration curve.Lithium distribution to the brain, evaluated using 7Li magnetic resonance spectroscopy, showed brain concentrations to be approximately half those in serum, occasionally increasing to 75–80%. Brain concentrations were weakly correlated with serum concentrations.Lithium is almost exclusively excreted via the kidney as a free ion and lithium clearance is considered to decrease with aging. No gender- or race-related differences in kinetics have been demonstrated. Renal insufficiency is associated with a considerable reduction in renal clearance of lithium and is considered a contraindication to its use, especially if a sodium-poor diet is required. During the last months of pregnancy, lithium clearance increases by 30–50% as a result of an increase in glomerular filtration rate. Lithium also passes freely from maternal plasma into breast milk.Numerous kinetic interactions have been described for lithium, usually involving a decrease in the drug’s clearance and therefore increasing its potential toxicity.Clinical pharmacology studies performed in healthy volunteers have investigated a possible effect of lithium on cognitive functions. Most of these studies reported a slight, negative effect on vigilance, alertness, learning and short-term memory after long-term administration only.Because of the narrow therapeutic range of lithium, therapeutic monitoring is the basis for optimal use and administration of this drug. Lithium dosages should be adjusted on the basis of the serum concentration drawn (optimally) 12 hours after the last dose. In patients receiving once-daily administration, the serum concentration at 24 hours should serve as the control value.The efficacy of lithium is clearly dose-dependent and reliably correlates with serum concentrations. It is now generally accepted that concentrations should be maintained between 0.6 and 0.8 mmol/L, although some authors still favour 0.8–1.2 mmol/L. With sustained-release preparations, and because of the later peak of serum lithium concentration, it is advised to keep serum concentrations within the upper range (0.8–1 mmol/L), rather than 0.6–0.8 mmol/L for standard formulations. It is controversial whether a reduced concentration is required in elderly people.The usual maintenance daily dose is 25–35 mmol (lithium carbonate 925–1300 mg) for patients aged <40 years; 20–25 mmol (740–925 mg) for those aged 40–60 years; and 15–20 mmol (550–740 mg) for patients aged >60 years. The initial recommended dose is usually 12–24 mmol (450–900 mg) per day, depending on age and bodyweight. The classical administration schedule is two or three times daily, although there is no strong evidence in favour of a three-times-daily schedule, and compliance with the midday dose is questionable. With a modern sustained-release preparation, the twice-daily schedule is well established, although one single evening dose is being recommended by a number of expert panels.

CYP2D6 and ABCB1 Genetic Variability : Influence on Paroxetine Plasma Level and Therapeutic Response

Paroxetine is characterized by large interindividual pharmacokinetic variability and heterogeneous response patterns. The present study investigates plasma concentration and therapeutic response to paroxetine for the influence of age, sex, and CYP2D6 and ABCB1 polymorphisms, the latter gene encoding for the permeability glycoprotein. Genotyping for CYP2D6 (alleles *3, *4, *5, *6, and *xN) and ABCB1 polymorphisms (61A>G, 2677G>T, and 3435C>T) was performed in 71 depressed patients who started 20 mg paroxetine per day and had plasma concentration measured after 2 weeks at a fixed dose. A dose increase to 30 mg per day was possible starting at week 2. For 63 patients, severity of depression (Montgomery-Åsberg Depression Rating Scale) was assessed at weeks 0, 2, and 4 and every 2 weeks thereafter until discontinuation. Persistent response was defined as 50% improvement from baseline score sustained from the first occurrence to study end point. Paroxetine concentration significantly differed between female and male patients (median, 28 versus 16 ng/mL; P = 0.001). Differences were not significant between CYP2D6 heterozygous and homozygous extensive metabolizers (median, 27 versus 22 ng/mL; P = 0.074) and between ABCB1 genotypes (P > 0.10). When considered in a multivariate model, CYP2D6 heterozygous extensive metabolizer phenotype (P = 0.062) and female gender (P = 0.001) predicted 1.3-fold and 1.6-fold higher paroxetine concentration, respectively, but fraction of explained variability was modest (21%). Frequency of persistent response at study end point did not significantly differ according to CYP2D6 heterozygous extensive metabolizer versus homozygous extensive metabolizer phenotype and ABCB1 polymorphisms in univariate analyses. After adjusting for age, sex, paroxetine concentration at week 2, and daily dose at study end point, ABCB1 genotype contributed to improving the model significantly for 61A>G (P = 0.043), but not 2677G>T (P = 0.068) and 3435C>T (P = 0.11). None of two poor metabolizers and four ultrarapid metabolizers showed persistent response to paroxetine. The hypothesis that permeability glycoprotein activity might be a relevant predictor of therapeutic response deserves to be further investigated while controlling for pharmacokinetic variability.

Childhood maltreatment and methylation of the glucocorticoid receptor gene NR3C1 in bipolar disorder

BACKGROUND Early-life adversities represent risk factors for the development of bipolar affective disorder and are associated with higher severity of the disorder. This may be the consequence of a sustained alteration of the hypothalamic-pituitary-adrenal (HPA) axis resulting from epigenetic modifications of the gene coding for the glucocorticoid receptor (NR3C1). AIMS To investigate whether severity of childhood maltreatment is associated with increased methylation of the exon 1F NR3C1 promoter in bipolar disorder. METHOD A sample of people with bipolar disorder (n = 99) were assessed for childhood traumatic experiences. The percentage of NR3C1 methylation was measured for each participant. RESULTS The higher the number of trauma events, the higher was the percentage of NR3C1 methylation (β = 0.52, 95% CI 0.46-0.59, P<<0.0001). The severity of each type of maltreatment (sexual, physical and emotional) was also associated with NR3C1 methylation status. CONCLUSIONS Early-life adversities have a sustained effect on the HPA axis through epigenetic processes and this effect may be measured in peripheral blood. This enduring biological impact of early trauma may alter the development of the brain and lead to adult psychopathological disorder.

Early effects of mood stabilizers on the Akt/GSK-3β signaling pathway and on cell survival and proliferation

RationaleLithium, some of the anticonvulsants, and several second-generation antipsychotic drugs are common medications widely prescribed to treat bipolar disorder. Molecular targets and cellular events that mediate their effects have been described for these drugs but are only partially unraveled. Few comparative studies have been performed.ObjectivesWe evaluated seven mood stabilizers (MS) in the same in vitro system and found several differences and similarities in their cellular mechanisms (proliferation and cell survival). As some MS were previously shown to activate the Akt/GSK-3β axis, this pathway was explored for other drugs.Materials and methodsThe SH-SY5Y cells were cultured in RPMI-1640 medium. Effects of MS drugs on serum-induced cell proliferation and on slowing of cell death were analyzed. Phosphorylation and expression of Akt-1 and GSK-3β mRNA and protein were assessed for the seven drugs as well.ResultsLithium, Valproate, Olanzapine, and Clozapine enhance proliferation and protect cells against serum withdrawal-induced injury. These drugs also activate Akt-1 and GSK-3β phosphorylation. Interestingly, gene expression of Akt-1 mRNA and protein, but not GSK-3β, was increased. The other drugs Lamotrigine, Haloperidol, and Carbamazepine did not affect cellular events nor activate Akt/GSK-3β axis.ConclusionValproate and atypical antipsychotics (Olanzapine and Clozapine) regulate SH-SY5Y cell proliferation and survival, activate the Akt/GSK-3β axis, and stimulate gene expression of Akt-1 mRNA and protein, as does Lithium. The other medications have no effect. The study shows the importance of the Akt/GSK-3 axis in MS actions but also pinpoints a different dependence of these drugs on this signaling axis.