Altered peripheral immune profiles in treatment-resistant depression: response to ketamine and prediction of treatment outcome.

A subset of patients with depression have elevated levels of inflammatory cytokines, and some studies demonstrate interaction between inflammatory factors and treatment outcome. However, most studies focus on only a narrow subset of factors in a patient sample. In the current study, we analyzed broad immune profiles in blood from patients with treatment-resistant depression (TRD) at baseline and following treatment with the glutamate modulator ketamine. Serum was analyzed from 26 healthy control and 33 actively depressed TRD patients free of antidepressant medication, and matched for age, sex and body mass index. All subjects provided baseline blood samples, and TRD subjects had additional blood draw at 4 and 24 h following intravenous infusion of ketamine (0.5 mg kg-1). Samples underwent multiplex analysis of 41 cytokines, chemokines and growth factors using quantitative immunoassay technology. Our a priori hypothesis was that TRD patients would show elevations in canonical pro-inflammatory cytokines; analyses demonstrated significant elevation of the pro-inflammatory cytokine interleukin-6. Further exploratory analyses revealed significant regulation of four additional soluble factors in patients with TRD. Several cytokines showed transient changes in level after ketamine, but none correlated with treatment response. Low pretreatment levels of fibroblast growth factor 2 were associated with ketamine treatment response. In sum, we found that patients with TRD demonstrate a unique pattern of increased inflammatory mediators, chemokines and colony-stimulating factors, providing support for the immune hypothesis of TRD. These patterns suggest novel treatment targets for the subset of patients with TRD who evidence dysregulated immune functioning.

Ketamine for rapid reduction of suicidal ideation: a randomized controlled trial.

BACKGROUND: Suicide is a devastating public health problem and very few biological treatments have been found to be effective for quickly reducing the intensity of suicidal ideation (SI). We have previously shown that a single dose of ketamine, a glutamate N-methyl-d-aspartate (NMDA) receptor antagonist, is associated with a rapid reduction in depressive symptom severity and SI in patients with treatment-resistant depression. METHOD: We conducted a randomized, controlled trial of ketamine in patients with mood and anxiety spectrum disorders who presented with clinically significant SI (n = 24). Patients received a single infusion of ketamine or midazolam (as an active placebo) in addition to standard of care. SI measured using the Beck Scale for Suicidal Ideation (BSI) 24 h post-treatment represented the primary outcome. Secondary outcomes included the Montgomery-Asberg Depression Rating Scale--Suicidal Ideation (MADRS-SI) score at 24 h and additional measures beyond the 24-h time-point. RESULTS: The intervention was well tolerated and no dropouts occurred during the primary 7-day assessment period. BSI score was not different between the treatment groups at 24 h (p = 0.32); however, a significant difference emerged at 48 h (p = 0.047). MADRS-SI score was lower in the ketamine group compared to midazolam group at 24 h (p = 0.05). The treatment effect was no longer significant at the end of the 7-day assessment period. CONCLUSIONS: The current findings provide initial support for the safety and tolerability of ketamine as an intervention for SI in patients who are at elevated risk for suicidal behavior. Larger, well-powered studies are warranted.

Regulation of neural responses to emotion perception by ketamine in individuals with treatment-resistant major depressive disorder.

The glutamate N-methyl-D-aspartate receptor antagonist ketamine has demonstrated antidepressant effects in individuals with treatment-resistant major depressive disorder (TRD) within 24 h of a single dose. The current study utilized functional magnetic resonance imaging (fMRI) and two separate emotion perception tasks to examine the neural effects of ketamine in patients with TRD. One task used happy and neutral facial expressions; the other used sad and neutral facial expressions. Twenty patients with TRD free of concomitant antidepressant medication underwent fMRI at baseline and 24 h following administration of a single intravenous dose of ketamine (0.5 mg kg(-1)). Adequate data were available for 18 patients for each task. Twenty age- and sex-matched healthy volunteers were scanned at one time point for baseline comparison. Whole-brain, voxel-wise analyses were conducted controlling for a family-wise error rate (FWE) of P<0.05. Compared with healthy volunteers, TRD patients showed reduced neural responses to positive faces within the right caudate. Following ketamine, neural responses to positive faces were selectively increased within a similar region of right caudate. Connectivity analyses showed that greater connectivity of the right caudate during positive emotion perception was associated with improvement in depression severity following ketamine. No main effect of group was observed for the sad faces task. Our results indicate that ketamine specifically enhances neural responses to positive emotion within the right caudate in depressed individuals in a pattern that appears to reverse baseline deficits and that connectivity of this region may be important for the antidepressant effects of ketamine.

Dissociable cortico-striatal connectivity abnormalities in major depression in response to monetary gains and penalties.

BACKGROUND: Individuals with major depressive disorder (MDD) are characterized by maladaptive responses to both positive and negative outcomes, which have been linked to localized abnormal activations in cortical and striatal brain regions. However, the exact neural circuitry implicated in such abnormalities remains largely unexplored. METHOD: In this study 26 unmedicated adults with MDD and 29 matched healthy controls (HCs) completed a monetary incentive delay task during functional magnetic resonance imaging (fMRI). Psychophysiological interaction (PPI) analyses probed group differences in connectivity separately in response to positive and negative outcomes (i.e. monetary gains and penalties). RESULTS: Relative to HCs, MDD subjects displayed decreased connectivity between the caudate and dorsal anterior cingulate cortex (dACC) in response to monetary gains, yet increased connectivity between the caudate and a different, more rostral, dACC subregion in response to monetary penalties. Moreover, exploratory analyses of 14 MDD patients who completed a 12-week, double-blind, placebo-controlled clinical trial after the baseline fMRI scans indicated that a more normative pattern of cortico-striatal connectivity pre-treatment was associated with greater improvement in symptoms 12 weeks later. CONCLUSIONS: These results identify the caudate as a region with dissociable incentive-dependent dACC connectivity abnormalities in MDD, and provide initial evidence that cortico-striatal circuitry may play a role in MDD treatment response. Given the role of cortico-striatal circuitry in encoding action-outcome contingencies, such dysregulated connectivity may relate to the prominent disruptions in goal-directed behavior that characterize MDD.

Medication adherence in a comparative effectiveness trial for bipolar disorder.

OBJECTIVE: Psychopharmacology remains the foundation of treatment for bipolar disorder, but medication adherence in this population is low (range 20-64%). We examined medication adherence in a multisite, comparative effectiveness study of lithium. METHOD: The Lithium Moderate Dose Use Study (LiTMUS) was a 6-month, six-site, randomized effectiveness trial of adjunctive moderate dose lithium therapy compared with optimized treatment in adult out-patients with bipolar I or II disorder (N=283). Medication adherence was measured at each study visit with the Tablet Routine Questionnaire. RESULTS: We found that 4.50% of participants reported missing at least 30% of their medications in the past week at baseline and non-adherence remained low throughout the trial (<7%). Poor medication adherence was associated with more manic symptoms and side-effects as well as lower lithium serum levels at mid- and post-treatment, but not with poor quality of life, overall severity of illness, or depressive symptoms. CONCLUSION: Participants in LiTMUS were highly adherent with taking their medications. The lack of association with possible predictors of adherence, such as depression and quality of life, could be explained by the limited variance or other factors as well as by not using an objective measure of adherence.

Plasma brain derived neurotrophic factor (BDNF) and response to ketamine in treatment-resistant depression.

Ketamine produces rapid antidepressant effects in treatment-resistant depression (TRD), but the magnitude of response varies considerably between individual patients. Brain-derived neurotrophic factor (BDNF) has been investigated as a biomarker of treatment response in depression and has been implicated in the mechanism of action of ketamine. We evaluated plasma BDNF and associations with symptoms in 22 patients with TRD enrolled in a randomized controlled trial of ketamine compared to an anaesthetic control (midazolam). Ketamine significantly increased plasma BDNF levels in responders compared to non-responders 240 min post-infusion, and Montgomery-Åsberg Depression Rating Scale (MADRS) scores were negatively correlated with BDNF (r=-0.701, p = 0.008). Plasma BDNF levels at 240 min post-infusion were highly negatively associated with MADRS scores at 240 min (r = -0.897, p=.002), 24 h (r = -0.791, p = 0.038), 48 h (r = -0.944, p = 0.001) and 72 h (r = -0.977, p = 0.010). No associations with BDNF were found for patients receiving midazolam. These data support plasma BDNF as a peripheral biomarker relevant to ketamine antidepressant response.

Using comparative effectiveness design to improve the generalizability of bipolar treatment trials data: contrasting LiTMUS baseline data with pre-existing placebo controlled trials.

BACKGROUND: Efficacy-based double-blind placebo controlled trials were conducted to establish efficacy and safety for FDA approval. Such designs allowed and encouraged the use of exclusion criteria to improve assay sensitivity and internal validity. The LiTMUS trial increased the representation of real-world individuals with bipolar disorder despite the acknowledgment that this compromises assay sensitivity. METHOD: To maximize generalizability, LiTMUS used broad inclusion and narrow exclusion criteria: participants experiencing mood symptoms of sufficient intensity (at least with a CGI-BP ≥ 3) that would warrant a change in treatment, and that lithium treatment would be a reasonable therapeutic option if they were randomized to it. At baseline demographic, illness, clinical, and treatment characteristics were collected. The LiTMUS study design and baseline sociodemographic data were compared to previous efficacy studies. RESULTS: As compared to the previous bipolar disorder efficacy studies, LiTMUS participants were of similar age, gender, weight and illness severity; however LiTMUS participants were more racially and ethnically representative of the general population, had a greater number of mood episodes in the past 12 months, more Axis I/II comorbidity, a greater number of prior suicide attempts, and higher functional capacity. CONCLUSIONS: LiTMUS was a comparative effectiveness trial that had broad inclusion and minimal exclusion criteria that produced a more representative sample comprised of real-world participants. This design enables the results of the LiTMUS study to be a more representative of real world pharmacotherapuetic outcomes. LIMITATIONS: Limitations include possible selection bias, paucity of sociodemographic data in efficacy trials, and lack of a placebo.

General medical burden in bipolar disorder: findings from the LiTMUS comparative effectiveness trial.

OBJECTIVE: This study examined general medical illnesses and their association with clinical features of bipolar disorder. METHOD: Data were cross-sectional and derived from the Lithium Treatment - Moderate Dose Use Study (LiTMUS), which randomized symptomatic adults (n = 264 with available medical comorbidity scores) with bipolar disorder to moderate doses of lithium plus optimized treatment (OPT) or to OPT alone. Clinically significant high and low medical comorbidity burden were defined as a Cumulative Illness Rating Scale (CIRS) score ≥4 and <4 respectively. RESULTS: The baseline prevalence of significant medical comorbidity was 53% (n = 139). Patients with high medical burden were more likely to present in a major depressive episode (P = .04), meet criteria for obsessive-compulsive disorder (P = .02), and experience a greater number of lifetime mood episodes (P = 0.02). They were also more likely to be prescribed a greater number of psychotropic medications (P = .002). Sixty-nine per cent of the sample was overweight or obese as defined by body mass index (BMI), with African Americans representing the racial group with the highest proportion of stage II obesity (BMI ≥35; 31%, n = 14). CONCLUSION: The burden of comorbid medical illnesses was high in this generalizable sample of treatment-seeking patients and appears associated with worsened course of illness and psychotropic medication patterns.

Gene-expression differences in peripheral blood between lithium responders and non-responders in the Lithium Treatment-Moderate dose Use Study (LiTMUS).

This study was designed to identify genes whose expression in peripheral blood may serve as early markers for treatment response to lithium (Li) in patients with bipolar disorder. Although changes in peripheral blood gene-expression may not relate directly to mood symptoms, differences in treatment response at the biochemical level may underlie some of the heterogeneity in clinical response to Li. Subjects were randomized to treatment with (n=28) or without (n=32) Li. Peripheral blood gene-expression was measured before and 1 month after treatment initiation, and treatment response was assessed after 6 months. In subjects treated with Li, 62 genes were differentially regulated in treatment responders and non-responders. Of these, BCL2L1 showed the greatest difference between Li responders and non-responders. These changes were specific to Li responders (n=9), and were not seen in Li non-responders or patients treated without Li, suggesting that they may have specific roles in treatment response to Li.

Using electronic medical records to enable large-scale studies in psychiatry: treatment resistant depression as a model.

BACKGROUND: Electronic medical records (EMR) provide a unique opportunity for efficient, large-scale clinical investigation in psychiatry. However, such studies will require development of tools to define treatment outcome. METHOD: Natural language processing (NLP) was applied to classify notes from 127 504 patients with a billing diagnosis of major depressive disorder, drawn from out-patient psychiatry practices affiliated with multiple, large New England hospitals. Classifications were compared with results using billing data (ICD-9 codes) alone and to a clinical gold standard based on chart review by a panel of senior clinicians. These cross-sectional classifications were then used to define longitudinal treatment outcomes, which were compared with a clinician-rated gold standard. RESULTS: Models incorporating NLP were superior to those relying on billing data alone for classifying current mood state (area under receiver operating characteristic curve of 0.85-0.88 v. 0.54-0.55). When these cross-sectional visits were integrated to define longitudinal outcomes and incorporate treatment data, 15% of the cohort remitted with a single antidepressant treatment, while 13% were identified as failing to remit despite at least two antidepressant trials. Non-remitting patients were more likely to be non-Caucasian (p<0.001). CONCLUSIONS: The application of bioinformatics tools such as NLP should enable accurate and efficient determination of longitudinal outcomes, enabling existing EMR data to be applied to clinical research, including biomarker investigations. Continued development will be required to better address moderators of outcome such as adherence and co-morbidity.

Correlates of subjective and objective burden among caregivers of patients with bipolar disorder.

OBJECTIVE: We examined the relationship between mood symptoms and episodes in patients with bipolar disorder and burden reported by their primary caregivers. METHOD: Data on subjective and objective burden reported by 500 primary caregivers for 500 patients with bipolar disorder participating in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) were collected using semistructured interviews. Patient data were collected prospectively over 1 year. The relationship between patient course and subsequent caregiver burden was examined. RESULTS: Episodes of patient depression, but not mood elevation, were associated with greater objective and subjective caregiver burden. Burden was associated with fewer patient days well over the previous year. Patient depression was associated with caregiver burden even after controlling for days well. CONCLUSION: Patient depression, after accounting for chronicity of symptoms, independently predicts caregiver burden. This study underscores the important impact of bipolar depression on those most closely involved with those whom it affects.

Pretreatment frontal EEG and changes in suicidal ideation during SSRI treatment in major depressive disorder.

OBJECTIVE: We investigated frontal quantitative EEG (QEEG) as predictor of changes in suicidal ideation (SI) during SSRI treatment in major depressive disorder (MDD). METHOD: Eighty-two subjects meeting DSM-IV criteria for MDD entered an 8-week, prospective, open-label treatment with flexible dose SSRIs and completed at least 4 weeks of treatment. We assessed MDD severity with the 17-item Hamilton Depression Rating Scale (HAM-D-17); change in SI was measured with HAM-D item no. 3. We recorded four-channel EEGs (F7-Fpz, F8-Fpz, A1-Fpz, A2-Fpz) before treatment. RESULTS: During the first 4 weeks of treatment 9 (11%) subjects experienced worsening SI. Left-right asymmetry of combined theta + alpha power correlated significantly with change in SI from baseline, even when adjusting for changes in depression severity (HAM-D-17) and for the SSRI utilized. CONCLUSION: Frontal QEEG parameters before treatment may predict worsening SI during SSRI treatment in MDD.

The safety and tolerability of duloxetine in depressed elderly patients with and without medical comorbidity.

AIM AND METHODS: The impact of medical comorbidity on the efficacy and tolerability of duloxetine in elderly patients with major depressive disorder (MDD) was investigated in this study. Data were obtained from a multicentre, randomised, double-blind, placebo-controlled study in 311 patients with MDD aged 65-89. The primary outcome measure was a prespecified composite cognitive score based on four cognitive tests: (i) Verbal Learning and Recall Test; (ii) Symbol Digit Substitution Test; (iii) 2-Digit Cancellation Test and (iv) Letter-Number Sequencing Test. Secondary measures included the Geriatric Depression Scale (GDS), 17-Item Hamilton Depression Scale (HAMD17), Clinical Global Impression-Severity (CGI-S) Scale, Visual Analogue Scale (VAS) for pain and 36-Item Short Form Health Survey (SF-36). Tolerability measures included adverse events reported as the reason for discontinuation and treatment-emergent adverse events (TEAEs). The consistency of the effect of duloxetine vs. placebo comparing patients with and without medical comorbidity (vascular disease, diabetes, arthritis or any of these) was investigated. RESULTS: Overall, duloxetine 60 mg/day demonstrated significantly greater improvement compared with placebo for the composite cognitive score, GDS and HAMD17 total scores, CGI-Severity, HAMD17 response and remission rates, and some of the SF-36 and VAS measures. There were few significant treatment-by-comorbidity subgroup interactions for these efficacy variables, or for adverse events reported as the reason for discontinuation and common TEAEs. CONCLUSIONS: The present analyses suggested that the efficacy of duloxetine on cognition and depression in elderly patients, and its tolerability, were not largely affected by the comorbidity status. These results further support the use of duloxetine in elderly patients with MDD.

T3 blood levels and treatment outcome in depression.

OBJECTIVE: We examined the correlation between the basal triiodothyronine resin uptake (T3-RU) levels in depressed subjects and the response to anti-depressant treatment. METHOD: We treated with fluoxetine 235 outpatients meeting DSM-IV criteria for major depression. We measured T3 resin uptake (T3-RU) levels before the onset of treatment. The 17-item Hamilton Rating Scale for Depression (Ham-D-17) was administered before, during and after the eight weeks of treatment to assess changes in depressive symptoms. RESULTS: 16 patients (6.8 percent) had low T3-RU levels (range 16.5-21), and 7 patients (3.0 percent) had high T3-RU levels (range 36-38). No relationship was found between T3-RU levels and clinical improvement, defined as either total Ham-D-17 score change or Ham-D-17 score < or = 7 in the last 3 weeks of treatment, even after adjusting for baseline severity of depression. CONCLUSION: Abnormal T3-RU levels are rather uncommon in outpatient depression and do not correlate with the response to antidepressant treatment or lack thereof.

Abnormal angular gyrus asymmetry in schizophrenia.

OBJECTIVE: Few studies have evaluated the parietal lobe in schizophrenia despite the fact that it has an important role in attention, memory, and language-all functions that have been reported to be abnormal in schizophrenia. The inferior parietal lobule, in particular, is of interest because it is not only part of the heteromodal association cortex but also is part of the semantic-lexical network, which also includes the planum temporale. Both the inferior parietal lobule, particularly the angular gyrus of the inferior parietal lobule, and the planum temporale are brain regions that play a critical role as biological substrates of language and thought. The authors compared volume and asymmetry measures of the individual gyri of the parietal lobe by means of magnetic resonance imaging (MRI) scans. METHOD: MRI scans with a 1. 5-Tesla magnet were obtained from 15 male chronic schizophrenic and 15 comparison subjects matched for age, gender, and parental socioeconomic status. RESULTS: Inferior parietal lobule volumes showed a leftward asymmetry (left 7.0% larger than right) in comparison subjects and a reversed asymmetry (left 6.3% smaller than right) in schizophrenic subjects. The angular gyrus accounted for this difference in asymmetry, with the left angular gyrus being significantly larger (18.7%) than the right in comparison subjects, a finding that was not observed in schizophrenic patients. A further test of angular gyrus asymmetry showed a reversal of the normal left-greater-than-right asymmetry in the schizophrenic patients. CONCLUSIONS: Patients with schizophrenia showed a reversed asymmetry in the inferior parietal lobule that was localized to the angular gyrus, a structure belonging to the heteromodal association cortex as well as being part of the semantic-lexical network. This finding contributes to a more comprehensive understanding of the neural substrates of language and thought disorder in schizophrenia.

An automated registration algorithm for measuring MRI subcortical brain structures.

An automated registration algorithm was used to elastically match an anatomical magnetic resonance (MR) atlas onto individual brain MR images. Our goal was to evaluate the accuracy of this procedure for measuring the volume of MRI brain structures. We applied two successive algorithms to a series of 28 MR brain images, from 14 schizophrenia patients and 14 normal controls. First, we used an automated segmentation program to differentiate between white matter, cortical and subcortical gray matter, and cerebrospinal fluid. Next, we elastically deformed the atlas segmentation to fit the subject's brain, by matching the white matter and subcortical gray matter surfaces. To assess the accuracy of these measurements, we compared, on all 28 images, 11 brain structures, measured with elastic matching, with the same structures traced manually on MRI scans. The similarity between the measurements (the relative difference between the manual and the automated volume) was 97% for whole white matter, 92% for whole gray matter, and on average 89% for subcortical structures. The relative spatial overlap between the manual and the automated volumes was 97% for whole white matter, 92% for whole gray matter, and on average 75% for subcortical structures. For all pairs of structures rendered with the automated and the manual method, Pearson correlations were between r = 0.78 and r = 0.98 (P < 0.01, N = 28), except for globus pallidus, where r = 0.55 (left) and r = 0. 44 (right) (P < 0.01, N = 28). In the schizophrenia group, compared to the controls, we found a 16.7% increase in MRI volume for the basal ganglia (i.e., caudate nucleus, putamen, and globus pallidus), but no difference in total gray/white matter volume or in thalamic MR volume. This finding reproduces previously reported results, obtained in the same patient population with manually drawn structures, and suggests the utility/efficacy of our automated registration algorithm over more labor-intensive manual tracings.

Parcellation of the human prefrontal cortex using MRI.

A methodology was developed for dividing prefrontal cortical gray matter into insular, orbital, inferior, middle, superior, cingulate, and frontal pole regions using anatomical criteria. This methodology was developed as a follow-up to one that measured whole prefrontal gray and white matter volumes in schizophrenic and control subjects. This study showed no overall volume differences in prefrontal cortex between schizophrenic and control subjects. The parcellation of prefrontal cortex was done to increase the probability of detecting abnormalities that were circumscribed to a particular portion of the region. A 1.5 Tesla magnet was used to acquire contiguous 1.5-mm coronal slices of the entire brain. Volumes were then measured in a group of right-handed male (n = 15) subjects. Gray matter was parcellated using criteria that were mainly based on gross anatomy, as visualized in 3-dimensional renderings of the brain. Reliability of the parcellation scheme was very high (r(i) = 0.80 and above). This methodology should be useful in the study of cortical pathology in a number of neurological disorders, including schizophrenia.