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Biomedical subjects

Gerard Sanacora

Publications and source records attributed to Gerard Sanacora.

At least 19 recordsLinked to original sources

Preliminary evidence of riluzole efficacy in antidepressant-treated patients with residual depressive symptoms.

BACKGROUND: Excessive glutamatergic neurotransmission may contribute to the pathophysiology of major depressive disorder (MDD). Recent evidence suggests that riluzole and other agents that target glutamate neurotransmission may show antidepressant activity. METHODS: Ten patients with treatment-resistant depression had riluzole added to their ongoing medication regimen for 6 weeks, followed by an optional 6-week continuation phase. Depression and anxiety severity were assessed using the Hamilton Depression Rating Scale (HDRS) and the Hamilton Anxiety Rating Scale (HARS). Linear mixed models were used to test for a linear trend in HDRS and HARS scores across time with treatment. RESULTS: Subjects' HDRS and HARS scores declined significantly following the initiation of riluzole augmentation therapy. The effect of riluzole was significant at the end of the first week of treatment and persisted for the 12-week duration of the study. CONCLUSIONS: These data suggest that riluzole augmentation produces antidepressant and anxiolytic effects in patients with treatment-resistant depression.

Adult↗

Antidepressant-like effects of ceftriaxone in male C57BL/6J mice.

BACKGROUND: Excessive glutamatergic neurotransmission is hypothesized to be associated with depressive-like behaviors and possibly major depressive disorder (MDD). Recent evidence that beta-lactam antibiotic agents stimulate uptake of glutamate suggests that this class of compounds might possess antidepressant-like activity. METHODS: Three-month old, male, C57BL/6J mice were administered ceftriaxone (200 mg/kg IP) for 14-18 days, then tested in the tail-suspension, forced swim, and novelty-suppressed feeding tests to determine whether ceftriaxone had similar effects to classical antidepressant compounds in these models. RESULTS: Ceftriaxone treatment had an antidepressant-like effect across models. Reduced immobility and decreased freezing were observed in the forced swim and tail suspension tests. The same trend was seen in novelty-suppressed feeding, but the effect was not statistically significant. CONCLUSION: Ceftriaxone demonstrates antidepressant-like effects in several mouse models. This is consistent with the hypothesis that enhanced uptake of glutamate might have antidepressant-like effects.

Animals↗

Can cognitive behavioral therapy reduce relapse rates of depression after ECT? a preliminary study.

OBJECTIVE: The goal of this study was to explore the potential of providing cognitive behavioral therapy (CBT) after an index course of electroconvulsive therapy (ECT) for depression to improve long-term outcome. METHOD: The Beck Depression Inventory (BDI) and Clinical Global Impression (CGI) scale were used to assess depression and treatment outcome for 6 patients who received 12 weeks of CBT after an index course and concurrent with a continuation course of ECT. RESULTS: Patients either maintained their response or showed decreased depressive symptoms at the 6-month post-index ECT evaluation. At the 9-month follow-up, 5 of 6 patients had BDI scores below their post-index ECT scores. The CGIs were rated "much improved" or "very much improved" by 5 patients at the termination of CBT. All 6 patients maintained or improved their CGIs at the 6-month follow-up. CONCLUSIONS: These results provide preliminary evidence that CBT after ECT is feasible and may extend the antidepressant effects ofECT.

Aged↗

Elevated cerebrospinal fluid substance p concentrations in posttraumatic stress disorder and major depression.

OBJECTIVE: The authors tested the hypothesis that concentrations of the pain-transmitting neuropeptide substance P are elevated in the CSF of patients with major depression or posttraumatic stress disorder (PTSD), which have overlapping symptoms. The authors also sought to determine if CNS substance P concentrations change on provocation of symptoms in PTSD patients. METHOD: The authors measured CSF substance P concentrations in medication-free patients with either major depression or PTSD and in healthy comparison subjects. Next, using a within-subject, crossover design, the authors sampled CSF for 6 hours through an indwelling subarachnoid catheter in PTSD patients before, during, and after exposure to a 60-minute traumatic or neutral videotape stimulus. RESULTS: Both depressed and PTSD patients had significantly elevated basal CSF substance P concentrations. In the challenge study, marked increases in CSF substance P concentrations were found only after precipitation of PTSD symptoms. CSF substance P concentrations increased by 169% and 90.6% of baseline levels at 10 and 70 minutes, respectively, after the start of the traumatic videotape but changed by only 1.1% and -8.1% of baseline levels 10 and 70 minutes after the start of the neutral videotape. CONCLUSIONS: These results suggest that elevated CNS substance P concentrations are involved in both major depression and PTSD. The marked increase in CSF substance P concentrations during and after the symptom-provoking stimulus, but not after the neutral stimulus, implicates CNS release of substance P in the mechanism of acute PTSD symptoms. These data also reveal that CNS substance P responds acutely to psychological stress in humans.

Acute Disease↗

N-acetylcysteine augmentation in serotonin reuptake inhibitor refractory obsessive-compulsive disorder.

RATIONALE: Dysfunction of glutamatergic neurotransmission has been implicated in the pathophysiology of obsessive-compulsive disorder (OCD) and recent clinical reports suggest that some glutamate modulating agents are efficacious in the treatment of this disorder. N-acetylcysteine (NAC) is a readily available amino acid compound that is thought to attenuate glutamatergic neurotransmission. NAC may be useful in treating psychiatric disorders involving glutamatergic dysfunction such as OCD. OBJECTIVES: To examine the efficacy of augmentation with NAC in a patient with serotonin reuptake inhibitor (SRI)-refractory OCD. METHODS: A patient with SRI-refractory OCD was treated with an off-label use of NAC augmentation of fluvoxamine over several weeks. RESULTS: NAC augmentation of fluvoxamine resulted in a marked decrease in Yale-Brown Obsessive Compulsive Scale (Y-BBOCS) score and a clinically significant improvement in OCD symptoms. CONCLUSIONS: NAC augmentation was effective in treating SRI-refractory OCD in this single case. Further research is warranted to investigate the use of NAC and other glutamate modulating agents in the treatment of OCD.

Acetylcysteine↗

Riluzole augmentation in treatment-resistant obsessive-compulsive disorder: an open-label trial.

BACKGROUND: Most patients with obsessive-compulsive disorder (OCD) show only partial reduction of symptoms with standard therapy. Recent imaging data suggests glutamatergic dysfunction in the corticostriatal pathway in OCD. We investigated the efficacy of augmentation therapy with riluzole, a glutamate-modulating agent, in treatment-resistant OCD. METHODS: Thirteen patients aged between 18 and 65 years with a primary diagnosis of OCD that had proven resistant to standard treatment were treated with the addition of riluzole to their existing pharmacotherapy. Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Hamilton Depression Inventory (HAM-D), and Hamilton Anxiety Inventory (HAM-A) scores were obtained weekly. RESULTS: Thirteen treatment-resistant OCD patients received riluzole 50 mg twice a day. Y-BOCS scores improved significantly over time. Of 13 patients, 7 (54%) demonstrated a >35% reduction in Y-BOCS scores, and 5 (39%) were categorized as treatment responders. HAM-D and HAM-A scores for the group also significantly improved over time. Riluzole was well tolerated with no serious adverse effects noted. CONCLUSIONS: Riluzole appears to have significant antiobsessional, antidepressant, and antianxiety properties. The addition of this agent may be of practical clinical benefit in patients with OCD.

Adult↗

Sex differences in diencephalon serotonin transporter availability in major depression.

BACKGROUND: Major depression is more prevalent in women than men. The present study evaluated if previous findings that demonstrated decreased 5-hydroxytryptamine (5-HT) transporter availability in depressed patients would be confirmed in a larger sample and also evaluated sex differences. METHODS: Depressed (n = 32) and healthy subjects (n = 32), including 16 pairs of women and men, participated in an iodine-123-2 beta-carbomethoxy-3beta-(4-iodophenyltropane) ([(123)I]beta-CIT) single photon emission computed tomography (SPECT) and a magnetic resonance imaging (MRI) scan. Participants were administered [(123)I]beta-CIT (225.7 +/- 3.7 MBq) and imaged 23.0 +/- 1.6 hours later. Statistical analyses included analysis of variance and a regression analysis of the main and interactive effects of age, sex, and depression. RESULTS: Overall, depressed patients demonstrated 12% lower diencephalon and no change in striatal or brainstem [(123)I]beta-CIT uptake. Significant age by sex, sex by depression, and age by sex by depression interactions were noted due to 22% lower diencephalon [(123)I]beta-CIT uptake in depressed women compared with less than a 1% decrease in depressed men. CONCLUSIONS: As observed previously, diencephalon 5-HT transporter availability is decreased in depressed patients. However, the decrease appears to be sex-specific and age-dependent. These findings suggest that serotonergic mechanisms mediating depressed mood differ between men and women in an age-dependent manner and may explain why young women respond better to treatment with selective serotonin reuptake inhibitor (SSRI) antidepressants.

Adult↗

Cortical gamma-aminobutyric acid concentrations in depressed patients receiving cognitive behavioral therapy.

BACKGROUND: Reduced gamma-aminobutyric acid (GABA) concentrations have been reported in plasma, cerebrospinal fluid, and cortex of depressed subjects. Treatment with both electroconvulsive therapy (ECT) and selective serotonin reuptake inhibitors (SSRI) increased occipital cortex GABA concentrations in prior studies. The purpose of this study was to determine whether treatment of major depression with cognitive behavioral therapy (CBT) produces similar changes in cortical GABA concentrations. METHODS: Occipital cortex GABA concentrations were measured in eight subjects with Major Depressive Disorder prior to and after a course of CBT using proton magnetic resonance spectroscopy. RESULTS: The effect of CBT on occipital cortex GABA content was different than that seen for ECT and SSRI medication treatment of depressed patients. CONCLUSIONS: This preliminary finding suggests CBT has a less robust effect on cortical GABA content than ECT and SSRI treatments and might indicate a difference between the mechanisms of antidepressant action.

Adult↗

Sex, GABA, and nicotine: the impact of smoking on cortical GABA levels across the menstrual cycle as measured with proton magnetic resonance spectroscopy.

BACKGROUND: Given that nicotine modulates amino acid neurotransmission, we sought to examine the impact of nicotine on cortical gamma-aminobutyric acid (GABA) levels in male and female smokers. METHODS: Healthy nicotine-dependent men (n = 10) and women (n = 6) underwent proton magnetic resonance spectroscopy (1H-MRS) to measure occipital cortex GABA concentrations. A subset of the smoking men (n = 5) underwent 1H-MRS scans before and after 48 hours of smoking abstinence, whereas each of the women were scheduled to undergo pre- and postabstinence scans during the follicular and luteal phases of one menstrual cycle. Healthy nonsmoking men (n = 7) and women (n = 13) underwent 1H-MRS for comparison. RESULTS: Short-term abstinence had no significant effect on cortical GABA concentrations in either men or women. There was, however, a significant effect of sex, diagnosis (smoker/nonsmoker), and menstrual cycle phase on cortical GABA levels, such that female smokers experienced a significant reduction in cortical GABA levels during the follicular phase and no cyclicity in GABA levels across the menstrual cycle, whereas cortical GABA levels were similar in smoking and nonsmoking men. CONCLUSIONS: Taken together with previous 1H-MRS data showing abnormalities in occipital cortex GABA concentrations in several affective disorders, our preliminary finding that nicotine modulation of GABA levels varies by sex provides a further rationale for investigating the impact of nicotine on central GABAergic function as a potential risk factor for women to experience depressive symptoms during smoking cessation.

Adult↗

Beyond monoamines: glutamatergic function in mood disorders.

The monoamine theory has implicated abnormalities in serotonin and norepinephrine in the pathophysiology of major depression and bipolar illness and contributed greatly to our understanding of mood disorders and their treatment. Nevertheless, some limitations of this model still exist that require researchers and clinicians to seek further explanation and develop novel interventions that reach beyond the confines of the monoaminergic systems. Recent studies have provided strong evidence that glutamate and other amino acid neurotransmitters are involved in the pathophysiology and treatment of mood disorders. Studies employing in vivo magnetic resonance spectroscopy have revealed altered cortical glutamate levels in depressed subjects. Consistent with a model of excessive glutamate-induced excitation in mood disorders, several antiglutamatergic agents, such as riluzole and lamotrigine, have demonstrated potential antidepressant efficacy. Glial cell abnormalities commonly associated with mood disorders may at least partly account for the impairment in glutamate action since glial cells play a primary role in synaptic glutamate removal. A hypothetical model of altered glutamatergic function in mood disorders is proposed in conjunction with potential antidepressant mechanisms of antiglutamatergic agents. Further studies elucidating the role of the glutamatergic system in the pathophysiology of mood and anxiety disorders and studies exploring the efficacy and mechanism of action of antiglutamatergic agents in these disorders, are likely to provide new targets for the development of novel antidepressant agents.

Bipolar Disorder↗

Brain serotonin transporter availability predicts treatment response to selective serotonin reuptake inhibitors.

BACKGROUND: Few studies have investigated the predictive value of central serotonin transporter (SERT) availability for treatment response to serotonin reuptake inhibitors (SSRIs). This study used brain imaging to examine the relationship between pretreatment brain SERT availability and transporter occupancy by SSRIs with treatment response in two independent depressed populations. METHODS: Study 1: Twenty-three patients with major depression underwent a single photon emission computed tomography (SPECT) measurement of brain SERT availability using [123I]beta-CIT ([123I]methyl 3beta-(4-iodophenyl) tropane-2beta-carboxylate. The SERT availability was correlated with treatment response to fluoxetine (20 mg/day) assessed with weekly Hamilton Depression Rating Scale (HDRS) for 6 weeks. Study 2: The second group included 10 depressed patients who received 6 weeks of paroxetine treatment (20 mg/day) and serial SPECT scans (baseline, during, and after the treatment). RESULTS: In Study 1, higher pretreatment diencephalic SERT availability significantly predicted better treatment response 4 weeks later. Similar results were found in Study 2 and supported Study 1 findings. The data showed that greater occupancy of diencephalic transporters by paroxetine correlated with better treatment response. CONCLUSIONS: Higher pretreatment availability and greater occupancy of SERT in diencephalon may predict better treatment course in response to SSRIs.

Adult↗

Mutation screen of the glutamate decarboxylase-67 gene and haplotype association to unipolar depression.

Abnormally low concentrations of brain gamma-aminobutyric acid (GABA) have been reported in unipolar depression. Almost all of the brain GABA is synthesized by glutamate decarboxylase (GAD) enzymes (GAD67 and GAD65). These enzymes, therefore, play a central role in brain GABA homeostasis. We screened all the 17 exons of the GAD67 gene for mutations using single strand conformation polymorphism (SSCP) or denaturing high pressure liquid chromatography (dHPLC) in a sample of 43 individuals diagnosed with major unipolar depression or other disorders with putative GABAergic dysfunction. We identified eight novel variants (five synonymous base substitutions, two insertion/deletions and one tandem repeat). Three relatively common (minor allele frequency >20%) single nucleotide polymorphisms (SNPs), located in the 5' non-coding region (exon 0), intron 8, and the 3' non-coding region (exon 16) of the gene, were genotyped in 103 European-American (EA) subjects with depression and 125 EA psychiatrically screened controls. Linkage disequilibrium (LD) and haplotype frequencies were estimated using the 3LOCUS program. Significant LD was observed between the intron 8 SNP and the exon 16 SNP and between the exon 0 SNP and the exon 16 SNP. Three common GAD67 haplotypes were observed in this population, which accounted for >90% of the possible GAD67 three-locus haplotypes. Comparison of SNP and haplotype frequencies between individuals with depression and controls revealed no differences. These results demonstrate a significant within-gene LD for GAD67 in the EA population and begin to establish a haplotype map for this gene. Furthermore, these results suggest that common genetic variation within the GAD67 gene does not play a major role in the predisposition to unipolar depression.

DNA↗

Subtype-specific alterations of gamma-aminobutyric acid and glutamate in patients with major depression.

BACKGROUND: Measurement of cortical gamma-aminobutyric acid (GABA) and glutamate concentrations is possible using proton magnetic resonance spectroscopy. An initial report, using this technique, suggested that occipital cortex GABA concentrations are reduced in patients with major depressive disorder (MDD) relative to healthy comparison subjects. OBJECTIVES: To replicate the GABA findings in a larger sample of MDD patients, to examine the clinical correlates of the GABA reductions in these subjects, and to examine other critical metabolite levels. DESIGN: Study for association. SETTING: Academic clinical research program. PARTICIPANTS: The GABA measurements were made on 38 healthy control subjects and 33 depressed subjects. INTERVENTIONS: Occipital cortex metabolite levels were measured using proton magnetic resonance spectroscopy. MAIN OUTCOME MEASURES: The levels of occipital cortex GABA, glutamate, N-acetylaspartate, aspartate, creatine, and choline-containing compounds, along with several measures of tissue composition, were compared between the 2 groups. RESULTS: Depressed subjects had significantly lower occipital cortex GABA concentrations compared with healthy controls (P =.01). In addition, mean glutamate levels were significantly increased in depressed subjects compared with healthy controls (P<.001). Significant reductions in the percentage of solid tissue (P =.009) and the percentage of white matter (P =.04) in the voxel were also observed. An examination of a combined database including subjects from the original study suggests that GABA and glutamate concentrations differ among MDD subtypes. CONCLUSIONS: The study replicates the findings of decreased GABA concentrations in the occipital cortex of subjects with MDD. It also demonstrates that there is a change in the ratio of excitatory-inhibitory neurotransmitter levels in the cortex of depressed subjects that may be related to altered brain function. Last, the combined data set suggests that magnetic resonance spectroscopy GABA measures may serve as a biological marker for a subtype of MDD.

Adult↗

Addition of the alpha2-antagonist yohimbine to fluoxetine: effects on rate of antidepressant response.

Electrophysiological studies suggest that alpha2-adrenoceptors profoundly affect monoaminergic neurotransmission by enhancing noradrenergic tone and serotonergic firing rates. Recent reports suggest that alpha2-antagonism may hasten and improve the response to antidepressant medications. To test this hypothesis, a randomized double-blind controlled trial was undertaken to determine if the combination of an alpha2-antagonist (yohimbine) with a selective serotonin reuptake agent (SSRI) (fluoxetine) results in more rapid onset of antidepressant action than an SSRI agent alone. In all, 50 subjects with a DSM-IV diagnosis of major depressive disorder confirmed by SCID interview were randomly assigned to receive either fluoxetine 20 mg plus placebo (F/P) or fluxetine 20 mg plus a titrated dose of yohimbine (F/Y). The yohimbine dose was titrated based on blood pressure changes over the treatment period, in a blind-preserving manner. Hamilton depression scale ratings (HDRS) and clinical global impression (CGI) ratings were obtained weekly over a period of 6 weeks. The rate of achieving categorical positive responses was significantly more rapid in the F/Y group compared to the F/P group using both the HDRS and the CGI scales as outcome measures in a survival analysis using a log-rank test (chi2(1) = 5.86, p = 0.016 and chi2(1) = 5.29, p = 0.021, respectively). At the last observed visit, 18 (69%) of the 26 F/Y subjects met the response criteria for CGI compared to 10 (42%) of 24 F/P subjects. Using the HDRS criteria, 17 (65%) of 26 F/Y subject vs 10 (42%) of 24 F/P subjects were responders. The addition of the alpha2-antagonist yohimbine to fluoxetine appears to hasten the antidepressant response. There is also a trend suggesting an increased percentage of responders to the combined treatment at the end of the 6-week trial.

Adolescent↗

Pindolol augmentation in depressed patients resistant to selective serotonin reuptake inhibitors: a double-blind, randomized, controlled trial.

BACKGROUND: Studies of pindolol augmentation of antidepressants in major depressive disorder have produced mixed results, and data in treatment-resistant patients are limited. Here, we report on a double-blind, randomized, controlled 6-week study of pindolol augmentation of selective serotonin reuptake inhibitors (SSRIs) in depressed outpatients resistant to SSRI monotherapy. METHOD: Forty-two outpatients with DSM-IV major depressive disorder who had an insufficient response to an adequate trial of an SSRI (fluoxetine, paroxetine, or sertraline) were randomly assigned to pindolol, 2.5 mg t.i.d., or sham augmentation, in addition to continued SSRI administration. For separate analysis, the control group underwent a single-blinded switch to pindolol, 2.5 mg t.i.d., from week 4 through week 6, while the active group was continued on pindolol augmentation (hemi-crossover design). Change in Hamilton Rating Scale for Depression (HAM-D) score from baseline to the end of week 3 was the primary outcome measure. Data were gathered from February 1994 to August 1998. RESULTS: Thirty-eight patients completed at least 1 week on protocol, with 21 and 17 randomly assigned to the pindolol and control groups, respectively. After 3 weeks on protocol, partial response rates (i.e., minimum 50% decrease from baseline in HAM-D score and maximum absolute score of 15) for the pindolol (19% [4/21]) and control (24% [4/17]) groups were comparable. At 3 weeks, the pindolol and control groups demonstrated mean +/- SD decreases in HAM-D scores of 6.5 +/- 9.8 and 9.7 +/- 7.2, respectively. There were no significant differences in antidepressant response or side effects between the 2 groups. CONCLUSION: These results do not support the efficacy of pindolol in augmenting clinical response to SSRIs in treatment-resistant depressed patients.

Adrenergic beta-Antagonists↗

Cerebral benzodiazepine receptors in depressed patients measured with [123I]iomazenil SPECT.

BACKGROUND: A recent magnetic resonance spectroscopy (MRS) study revealed low gamma-aminobutyric acid (GABA) levels in the occipital cortex of depressed patients. No in vivo study has been reported to measure postsynaptic GABA receptors in the patients. METHODS: Cortical benzodiazepine (BZ) binding to GABA(A) receptors was measured with [(123)I]iomazenil and single photon emission computed tomography in unmedicated patients with unipolar major depression (n = 13) and healthy subjects (n = 19). Group differences were evaluated by means of statistical parametric mapping (SPM) with partial volume correction for gray matter. Occipital GABA levels were determined by proton MRS in a subgroup (n = 6) of the patients. RESULTS: No evidence of altered BZ binding was found in patients with depression compared with healthy control subjects in the SPM analysis. Although reduction in gray matter volume was observed in the frontal cortex and amygdala of the patients, partial volume correction of the atrophy did not change the result of unaltered BZ binding. GABA levels were found lower in the occipital cortex; however, BZ binding did not show significant relationship to GABA levels. CONCLUSIONS: GABA(A) receptor binding measured in vivo with BZ radioligand binding are not altered in patients with depression.

Adult↗