Inclusion of genetic variants in an ensemble of gradient boosting decision trees does not improve the prediction of citalopram treatment response.

Identifying in advance who is unlikely to respond to a specific antidepressant treatment is crucial to precision medicine efforts. The current work leverages genome-wide genetic variation and machine learning to predict response to the antidepressant citalopram using data from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial (n = 1257 with both valid genomic and outcome data). A confirmatory approach selected 11 SNPs previously reported to predict response to escitalopram in a sample different from the current study. A novel exploratory approach selected SNPs from across the genome using nested cross-validation with elastic net logistic regression with a predominantly lasso penalty (alpha = 0.99). SNPs from each approach were combined with baseline clinical predictors and treatment response outcomes were predicted using a stacked ensemble of gradient boosting decision trees. Using pre-treatment clinical and symptom predictors only, out-of-fold prediction of a novel treatment response definition based on STAR*D treatment guidelines was acceptable, AUC = .659, 95% CI [0.629, 0.689]. The inclusion of SNPs using confirmatory or exploratory selection methods did not improve the out-of-fold prediction of treatment response (AUCs were .662, 95% CI [0.632, 0.692] and .655, 95% CI [0.625, 0.685], respectively). A similar pattern of results were observed for the secondary outcomes of the presence or absence of distressing side effects regardless of treatment response and achieving remission or satisfactory partial response, assuming medication tolerance. In the current study, incorporating SNP variation into prognostic models did not enhance the prediction of citalopram response in the STAR*D sample.

Symptom-network dynamics in irritable bowel syndrome with comorbid panic disorder using electronic momentary assessment: A randomized controlled trial of escitalopram vs. placebo.

INTRODUCTION: Momentary ecological assessment indicated alleviated abdominal pain in escitalopram treatment of irritable bowel syndrome (IBS) with comorbid panic disorder. Hitherto, little is known about symptom formation, i.e., how psychological impact physical symptoms, and vice versa, and about the effect of SSRI-treatment on symptom formation. OBJECTIVE: To investigate how psychological and somatic symptoms co-vary over time in IBS patients with comorbid panic disorder and how they are affected by escitalopram treatment. METHODS: Experience sampling data from 14 IBS patients with panic disorder were obtained from a single-centre, double-blind, parallel-group, randomized controlled trial on escitalopram versus placebo. At baseline, after three and six months, multilevel time-lagged linear regression analysis was used to construct symptom networks. Network connections represented coefficients between various affect and gastrointestinal items. RESULTS: Connectivity increased up to 3 months in both groups. Between 3 and 6 months, connectivity decreased for placebo and further increased in the escitalopram group. Additionally, a steep increase in node strength for negative affect nodes was observed in the escitalopram network and the opposite for positive affect nodes. Over time, group symptom networks became increasingly different from each other. Anxious-anxious and enthusiastic-relaxed became significantly different between groups at 6 months. The connection that changed significantly in all analyses was anxious-anxious. CONCLUSIONS: Escitalopram treatment was associated with changes in the symptom networks in IBS patients with panic disorder. While mood and physical symptoms improve over time, mainly connectivity between mood nodes changed, possibly pointing towards a healthier emotion regulation resulting in alleviation of physical symptoms.

Assessment of citalopram and escitalopram on neuroblastoma cell lines. Cell toxicity and gene modulation.

Selective serotonin reuptake inhibitors (SSRI) are common antidepressants which cytotoxicity has been assessed in cancers notably colorectal carcinomas and glioma cell lines. We assessed and compared the cytotoxicity of 2 SSRI, citalopram and escitalopram, on neuroblastoma cell lines. The study was performed on 2 non-MYCN amplified cell lines (rat B104 and human SH-SY5Y) and 2 human MYCN amplified cell lines (IMR32 and Kelly). Citalopram and escitalopram showed concentration-dependent cytotoxicity on all cell lines. Citalopram was more cytotoxic than escitalopram. IMR32 was the most sensitive cell line. The absence of toxicity on human primary Schwann cells demonstrated the safety of both molecules for myelin. The mechanisms of cytotoxicity were explored using gene-expression profiles and quantitative real-time PCR (qPCR). Citalopram modulated 1 502 genes and escitalopram 1 164 genes with a fold change ≥ 2. 1 021 genes were modulated by both citalopram and escitalopram; 481 genes were regulated only by citalopram while 143 genes were regulated only by escitalopram. Citalopram modulated 69 pathways (KEGG) and escitalopram 42. Ten pathways were differently modulated by citalopram and escitalopram. Citalopram drastically decreased the expression of MYBL2, BIRC5 and BARD1 poor prognosis factors of neuroblastoma with fold-changes of -107 (p<2.26 10-7), -24.1 (p<5.6 10-9) and -17.7 (p<1.2 10-7). CCNE1, AURKA, IGF2, MYCN and ERBB2 were more moderately down-regulated by both molecules. Glioma markers E2F1, DAPK1 and CCND1 were down-regulated. Citalopram displayed more powerful action with broader and distinct spectrum of action than escitalopram.

Cost-Effective Drug Switch Options After Unsuccessful Treatment With an SSRI for Depression.

OBJECTIVE: Multiple treatment options are available for patients who do not respond to initial treatment for major depressive disorder. Previous results show that bupropion, sertraline, and venlafaxine are comparable in terms of therapeutic effectiveness following unsuccessful treatment with citalopram. In this study, we extended these results by incorporating costs of treatment to determine if one option was more cost-effective relative to others. METHODS: In the STAR*D (Sequenced Treatment Alternatives to Relieve Depression) trial, 727 patients were randomly assigned to a switch drug treatment during level 2; 239 (33%) were assigned to bupropion, 238 (33%) to sertraline, and 250 (34%) to venlafaxine. For each study medication, the total costs included the costs of the medication, other concomitant medication and antidepressants, and health care facility utilization. Effectiveness was measured as remission and response. Cost-effectiveness was assessed as net health benefits. Stochastic analysis was performed by using the bootstrapping method. RESULTS: During level 2, mean medication costs were significantly higher for venlafaxine than for bupropion and sertraline ($968, $607, and $703, respectively). There were no significant differences among the switch medications in costs for other medications and health care facility utilization. Although the total costs were significantly different for the three medications (p=.025), none of the pairwise differences between medications were significant. Also, after jointly estimating costs and effects, the analyses found that net health benefits were not significantly different among the three drugs. CONCLUSIONS: After unsuccessful treatment with citalopram, the switch options of bupropion, sertraline, and venlafaxine were not significantly different from each other in terms of cost-effectiveness.

Chronic escitalopram treatment attenuated the accelerated rapid eye movement sleep transitions after selective rapid eye movement sleep deprivation: a model-based analysis using Markov chains.

BACKGROUND: Shortened rapid eye movement (REM) sleep latency and increased REM sleep amount are presumed biological markers of depression. These sleep alterations are also observable in several animal models of depression as well as during the rebound sleep after selective REM sleep deprivation (RD). Furthermore, REM sleep fragmentation is typically associated with stress procedures and anxiety. The selective serotonin reuptake inhibitor (SSRI) antidepressants reduce REM sleep time and increase REM latency after acute dosing in normal condition and even during REM rebound following RD. However, their therapeutic outcome evolves only after weeks of treatment, and the effects of chronic treatment in REM-deprived animals have not been studied yet. RESULTS: Chronic escitalopram- (10 mg/kg/day, osmotic minipump for 24 days) or vehicle-treated rats were subjected to a 3-day-long RD on day 21 using the flower pot procedure or kept in home cage. On day 24, fronto-parietal electroencephalogram, electromyogram and motility were recorded in the first 2 h of the passive phase. The observed sleep patterns were characterized applying standard sleep metrics, by modelling the transitions between sleep phases using Markov chains and by spectral analysis. Based on Markov chain analysis, chronic escitalopram treatment attenuated the REM sleep fragmentation [accelerated transition rates between REM and non-REM (NREM) stages, decreased REM sleep residence time between two transitions] during the rebound sleep. Additionally, the antidepressant avoided the frequent awakenings during the first 30 min of recovery period. The spectral analysis showed that the SSRI prevented the RD-caused elevation in theta (5-9 Hz) power during slow-wave sleep. Conversely, based on the aggregate sleep metrics, escitalopram had only moderate effects and it did not significantly attenuate the REM rebound after RD. CONCLUSION: In conclusion, chronic SSRI treatment is capable of reducing several effects on sleep which might be the consequence of the sub-chronic stress caused by the flower pot method. These data might support the antidepressant activity of SSRIs, and may allude that investigating the rebound period following the flower pot protocol could be useful to detect antidepressant drug response. Markov analysis is a suitable method to study the sleep pattern.

Neuroendocrine assessment of serotonergic, dopaminergic, and noradrenergic functions in alcohol-dependent individuals.

BACKGROUND: Alcohol dependence has been associated with reduced function of serotonin, dopamine as well as noradrenaline activities in several neuroendocrine studies. To our knowledge, there is, however, no study investigating all these 3 systems with the use of neuroendocrine methods in one and the same alcohol-dependent individual. METHODS: Alcohol-dependent individuals (n = 42) and controls (n = 28) participated in the neuroendocrine test series. Central serotonergic neurotransmission was assessed by the prolactin (PRL) response to citalopram (CIT). The postsynaptic DRD2 function was measured by the growth hormone (GH) response to apomorphine (APO) and the postsynaptic α2-adrenoceptor function by GH response to clonidine (CLON). RESULTS: In the alcohol-dependent individuals, the PRL concentrations were significantly lower at the time points 240 minutes and 300 minutes after CIT administration and mean delta PRL value was significantly reduced by 45% in comparison with controls. There were no significant differences in APO-GH and CLON-GH concentrations at any time points or in mean delta GH values between the groups. An impaired monoaminergic profile, including all 3 systems, was significantly more frequent in alcohol-dependent individuals than controls (43% vs. 6% respectively). CONCLUSIONS: The monoaminergic dysfunction was restricted to an impairment of the serotonergic system, suggesting that this system is especially vulnerable to long-term and excessive alcohol consumption. Moreover, impaired monoaminergic profiles, including low responses in 2 or 3 systems, were more frequently observed in alcohol-dependent individuals than in controls. Such impaired profiles may be of clinical importance, but further studies are needed.

SSRI effects on pyschomotor performance: assessment of citalopram and escitalopram on normal subjects.

INTRODUCTION: Standard aeromedical doctrine dictates that aircrew receiving treatment for depression are grounded during treatment and follow-up observation, generally amounting to at least 1 yr. The Canadian Forces has initiated a program to return selected aircrew being treated for depression to restricted flying duties once stabilized on an approved antidepressant with resolution of depression. The currently approved medications are sertraline (a selective serotonin reuptake inhibitor) and bupropion (noradrenaline and dopamine reuptake inhibitor). This study was undertaken to determine whether or not citalopram or escitalopram affect psychomotor performance. METHOD: In a double-blind crossover protocol with counter-balanced treatment order, 24 normal volunteer subjects (14 men and 10 women) were assessed for psychomotor performance during placebo, citalopram (40 mg), and escitalopram (20 mg) treatment. Each treatment arm lasted 2 wk, involving a daily morning ingestion of one capsule. There was a 1-wk washout period between medication courses. Subjects completed a drug side-effect questionnaire and were tested on three psychomotor test batteries once per week. RESULTS: Neither citalopram nor escitalopram affected serial reaction time, logical reasoning, serial subtraction, multitask, or MacWorth clock task performance. CONCLUSIONS: While we found some of the expected side effects due to citalopram and escitalopram, there was no impact on psychomotor performance. These findings support the possibility of using citalopram and escitalopram for returning aircrew to restricted flight duties (non-tactical flying) under close observation as a maintenance treatment after full resolution of depression.

Escitalopram: a review of its use in the management of major depressive disorder.

Escitalopram (Cipralex, Lexapro), the active S-enantiomer of the racemic selective serotonin reuptake inhibitor (SSRI) citalopram (RS-citalopram), is a highly selective inhibitor of the serotonin transporter protein. It possesses a rapid onset of antidepressant activity, and is an effective and generally well tolerated treatment for moderate-to-severe major depressive disorder (MDD). Pooled analyses from an extensive clinical trial database suggest that escitalopram is consistently more effective than citalopram in moderate-to-severe MDD. Preliminary studies suggest that escitalopram is as effective as other SSRIs and the extended-release (XR) formulation of the serotonin/noradrenaline (norepinephrine) reuptake inhibitor venlafaxine, and may have cost-effectiveness and cost-utility advantages. However, additional longer-term, comparative studies evaluating specific efficacy, tolerability, health-related quality of life and economic indices would be helpful in definitively positioning escitalopram relative to these other agents in the treatment of MDD. Nevertheless, available clinical and pharmacoeconomic data indicate that escitalopram is an effective first-line option in the management of patients with MDD.

Screening antidepressants in the chick separation-stress paradigm.

RATIONALE: Clinical research has indicated that antidepressants are efficacious in the treatment of anxiety disorders, especially when repeatedly administered. However, few animal models of anxiety are sensitive to antidepressants, a finding that may be due to procedures limited to acute administrations. OBJECTIVES: The purpose of the present research was to further validate the chick separation-stress paradigm as an animal model of anxiety by examining its sensitivity to the monoamine oxidase inhibitor (MAOI) phenelzine (6.25, 12.5, 25.0 mg/kg), the tricyclic antidepressant (TCA) imipramine (5.0, 10.0, 20.0 mg/kg), the selective serotonin reuptake inhibitor (SSRI) citalopram (1.0, 2.5, 5.0 mg/kg), and the norepinephrine reuptake inhibitor (NRI) maprotiline (5.0, 10.0, 20.0 mg/kg) under acute (no pretreatment) or repeated (3 or 6 days pretreatment) administration procedures. METHODS: Following any pretreatment, 8-day-old chicks received their respective vehicle or drug probe injection 15 min before tests in either a "mirror" (low stress) or "no mirror" (high stress) condition for a 180-s isolation period. The dependent measures were distress vocalizations to index separation stress and sleep onset latency to index sedation. RESULTS: The model was sensitive to acutely administered phenelzine (MAOI), imipramine (TCA), and maprotiline (NRI), but not citalopram (SSRI) and retained its sensitivity to these drug probes across both repeated administration procedures. None of the drug probes possessed any sedative properties. CONCLUSIONS: These results help extend the validity and utility of the chick separation-stress paradigm as an animal model of anxiety by demonstrating its sensitivity to antidepressants under both acute and repeated administration procedures.

Specific in vitro binding of (S,S)-[3H]MeNER to norepinephrine transporters.

The aim of this study was to determine the selectivity of (S,S)-2-(alpha-(2-methoxyphenoxy)benzyl)morpholine (MeNER) binding to norepinephrine transporters (NET). Quantitative autoradiography studies of NET binding were performed in brains of wildtype mice and those of mutant mice lacking one or two alleles of the NET gene. [3H]MeNER binding in the wildtype mouse brains was consistent with previously reported distributions of NET. Highest levels were found in the locus coeruleus, thalamus, hypothalamus, and bed nucleus of stria terminalis. Specific binding in these regions was approximately 50% in the heterozygous NET mice and negligible in the NET knockout mice. Binding in the wildtype mouse brains was displaced by the NET ligand, nisoxetine, but not by the serotonin or dopamine transporter blockers, citalopram or GBR 12935. [3H]MeNER displayed much higher affinity for NET than for SERT or DAT in homogenate binding studies. Each of these features supports the binding specificity of this candidate in vivo NET ligand.

Escitalopram: superior to citalopram or a chiral chimera?

BACKGROUND: Escitalopram is the active isomer of the antidepressant citalopram. In theory single-isomer drugs may be superior but few have been found to have clinically significant advantages. The manufacturer claims that escitalopram has more efficacy and a faster onset of effect than citalopram. The purpose of this study was to assess how far these claims are justified. METHODS: Relevant trial reports were requested from H. Lundbeck A/S and the Swedish drug regulatory authority. The trials consisted of a pooled analysis of 1,321 patients from one unpublished, one partly published and one published eight-week trial, as well as a 24-week trial with 357 patients published as a poster. The studies compared escitalopram with placebo and/or citalopram in outpatients aged or=18 years who met specified criteria for depression. The trials' quality was assessed with Moncrieff et al.'s quality assessment instrument and the results compared with the claims from the advertisements. RESULTS: The advertising claims are not justified because they are based on secondary outcomes, non-intention-to-treat analyses and arbitrarily defined subgroups. The subgroup results are inconsistent. Methodological flaws in the trials could account for the differences found. Even if the differences claimed were real they appear too small to justify higher prices. CONCLUSIONS: On the evidence available to us the manufacturer's claims of superiority for escitalopram over citalopram are unwarranted. The Swedish and Danish drug regulatory authorities reached similar conclusions. This highlights the need for wider dissemination of national authorities' statements to other countries affected by the European Union's mutual recognition procedure.

Escitalopram : a review of its use in the management of major depressive and anxiety disorders.

UNLABELLED: Escitalopram is the therapeutically active S-enantiomer of RS-citalopram, a commonly prescribed SSRI. The R-enantiomer is essentially pharmacologically inactive. Escitalopram 10 or 20 mg/day produced significantly greater improvements in standard measurements of antidepressant effect (Montgomery-Asberg Depression Rating Scale [MADRS], Clinical Global Impressions Improvement and Severity scales [CGI-I and CGI-S] and Hamilton Rating Scale for Depression [HAM-D]) in patients with major depressive disorder (MDD) than placebo in several 8-week, placebo-controlled, randomised, double-blind, multicentre studies. Symptom improvement was rapid, with some parameters improving within 1-2 weeks of starting escitalopram treatment. In addition, escitalopram showed earlier and clearer separation from placebo than RS-citalopram, at one-quarter to half the dosage, in 8-week, placebo-controlled trials; had significantly better efficacy than RS-citalopram in a subgroup of patients with moderate MDD in a 24-week trial; and produced sustained response and remission significantly faster than venlafaxine extended release in patients with MDD. Escitalopram reduced relapse rate compared with placebo and increased the percentage of patients in remission in long-term trials (up to 52 weeks). Consistently significant improvements for all efficacy parameters were also observed in patients with generalised anxiety disorder, social anxiety disorder and panic disorder treated with escitalopram for 8-12 weeks in individual, randomised, placebo-controlled, double-blind investigations. The good tolerability profile of escitalopram is predictable and similar to that of RS-citalopram. Such adverse events as nausea, ejaculatory problems, diarrhoea and insomnia are expected but, with the exception of ejaculatory problems and nausea, which is mild and transient, these were generally no more frequent than with placebo in fully published clinical trials. No adverse events not previously seen in acute trials were reported with long-term use. CONCLUSIONS: Escitalopram, the S-enantiomer of RS-citalopram, is a highly selective inhibitor for the serotonin transporter, ameliorates depressive symptoms in patients with MDD at half the RS-citalopram dosage, has a rapid onset of symptom improvement and has a predictable tolerability profile of generally mild adverse events. Like RS-citalopram, escitalopram is expected to have a low propensity for drug interactions, a potential benefit in the management of patients with comorbidities. In combination, these properties place escitalopram, like other SSRIs, as first-line therapy in patients with MDD. Escitalopram is indicated for use in patients with panic disorder in Europe and, should further evidence confirm early findings that escitalopram reduces anxiety, the drug may well find an additional role in the management of anxiety disorders.

Serotonin transporter function in vivo: assessment by chronoamperometry.

Local application of selective serotonin reuptake inhibitors, fluvoxamine and citalopram, prolonged the clearance of exogenously administered serotonin (5-HT) in both the dentate gyrus and CA3 region of the dorsal hippocampus, as measured using in vivo chronoamperometry. These effects were abolished in rats pretreated with 5,7-dihydroxytryptamine. The NE uptake inhibitors, desipramine and protriptyline, did not alter the 5-HT signal in the CA3 region, but prolonged the clearance of 5-HT in the dentate gyrus; this effect was absent in rats pretreated with 6-hydroxydopamine. From these data, it is inferred that both the SERT and NET contribute to the active clearance of exogenously applied 5-HT in the dentate gyrus. In another experiment, cyanopindolol, an antagonist of the serotonin terminal autoreceptor, also prolonged the clearance of 5-HT from the CA3 region. These and other data have generated a working hypothesis that activation of the terminal serotonin autoreceptor enhances the kinetics of 5-HT uptake through an effect on the serotonin transporter.