Faculty Bibliography

BACKGROUND: At least one-third of patients with major depressive disorder (MDD) have treatment-resistant depression (TRD), defined as lack of response to two or more adequate antidepressant trials. For these patients, novel antidepressant treatments are urgently needed. METHODS: The current study is a phase IIa open label clinical trial examining the efficacy and tolerability of a combination of dextromethorphan (DM) and the CYP2D6 enzyme inhibitor quinidine (Q) in patients with TRD. Dextromethorphan acts as an antagonist at the glutamate N-methyl-d-aspartate (NMDA) receptor, in addition to other pharmacodynamics properties that include activity at sigma-1 receptors. Twenty patients with unipolar TRD who completed informed consent and met all eligibility criteria we enrolled in an open-label study of DM/Q up to 45/10mg by mouth administered every 12h over the course of a 10-week period, and constitute the intention to treat (ITT) sample. Six patients discontinued prior to study completion. RESULTS: There was no treatment-emergent suicidal ideation, psychotomimetic or dissociative symptoms. Montgomery-Asberg Depression Rating Scale (MADRS) score was reduced from baseline to the 10-week primary outcome (mean change: -13.0+/-11.5, t19=5.0, p<0.001), as was QIDS-SR score (mean change: -5.9+/-6.6, t19=4.0, p<0.001). The response and remission rates in the ITT sample were 45% and 35%, respectively. LIMITATIONS: Open-label, proof-of-concept design. CONCLUSIONS: Herein we report acceptable tolerability and preliminary efficacy of DM/Q up to 45/10mg administered every 12h in patients with TRD. Future larger placebo controlled randomized trials in this population are warranted.

OBJECTIVE: Immune alterations may play a role in bipolar disorder etiology; however, the relationship between overall immune system functioning and mood symptom severity is unknown. METHODS: The two comparative effectiveness trials, the Clinical and Health Outcomes Initiatives in Comparative Effectiveness for Bipolar Disorder Study (Bipolar CHOICE) and the Lithium Treatment Moderate-Dose Use Study (LiTMUS), were similar trials among patients with bipolar disorder. At study entry, white blood cell count and bipolar mood symptom severity (via Montgomery-Aasberg Depression Rating Scale and Bipolar Inventory of Symptoms Scale) were assessed. We performed analysis of variance and linear regression analyses to investigate relationships between deviations from median white blood cell and multinomial regression analysis between higher and lower white blood cell levels. All analyses were adjusted for age, gender, body mass index, smoking, diabetes, hypertension and hyperlipidemia. RESULTS: Among 482 Bipolar CHOICE participants, for each 1.0 x 109/L white blood cell deviation, the overall Bipolar Inventory of Symptoms Scale severity increased significantly among men (coefficient = 2.13; 95% confidence interval = [0.46, -3.79]; p = 0.013), but not among women (coefficient = 0.87; 95% confidence interval = [-0.87, -2.61]; p = 0.33). Interaction analyses showed a trend toward greater Bipolar Inventory of Symptoms Scale symptom severity among men (coefficient = 1.51; 95% confidence interval = [-0.81, -3.82]; p = 0.2). Among 283 LiTMUS participants, higher deviation from the median white blood cell showed a trend toward higher Montgomery-Aasberg Depression Rating Scale scores among men (coefficient = 1.33; 95% confidence interval = [-0.22, -2.89]; p = 0.09), but not among women (coefficient = 0.34; 95% confidence interval = [-0.64, -1.32]; p = 0.50). When combining LiTMUS and Bipolar CHOICE, Montgomery-Aasberg Depression Rating Scale scores increased significantly among men (coefficient = 1.09; 95% confidence interval = [0.31, -1.87]; p = 0.006) for each 1.0 x 109/L white blood cell deviation, whereas we found a weak association among women (coefficient = 0.55; 95% confidence interval = [-0.20, -1.29]; p = 0.14). Lower and higher white blood cell levels correlated with greater symptom severity and specific symptoms, varying according to gender. CONCLUSION: Deviations in an overall immune system marker, even within the normal white blood cell range, correlated with mood symptom severity in bipolar disorder, mostly among males. Studies are warranted investigating whether white blood cell count may predict response to mood-stabilizing treatment.

Capitalizing on recent advances in resting-state functional connectivity magnetic resonance imaging (rs-fcMRI) and the distinctive paradigm of rapid mood normalization following ketamine treatment, the current study investigated intrinsic brain networks in major depressive disorder (MDD) during a depressive episode and following treatment with ketamine. Medication-free patients with MDD and healthy control subjects (HC) completed baseline rs-fcMRI. MDD patients received a single infusion of ketamine and underwent repeated rs-fcMRI at 24 h posttreatment. Global brain connectivity with global signal regression (GBCr) values were computed as the average of correlations of each voxel with all other gray matter voxels in the brain. MDD group showed reduced GBCr in the prefrontal cortex (PFC) but increased GBCr in the posterior cingulate, precuneus, lingual gyrus, and cerebellum. Ketamine significantly increased GBCr in the PFC and reduced GBCr in the cerebellum. At baseline, 2174 voxels of altered GBCr were identified, but only 310 voxels significantly differed relative to controls following treatment (corrected alpha<0.05). Responders to ketamine showed increased GBCr in the lateral PFC, caudate, and insula. Follow-up seed-based analyses illustrated a pattern of dysconnectivity between the PFC/subcortex and the rest of the brain in MDD, which appeared to normalize postketamine. The extent of the functional dysconnectivity identified in MDD and the swift and robust normalization following treatment suggest that GBCr may serve as a treatment response biomarker for the development of rapid acting antidepressants. The data also identified unique prefrontal and striatal circuitry as a putative marker of successful treatment and a target for antidepressants' development.Neuropsychopharmacology advance online publication, 12 October 2016; doi:10.1038/npp.2016.186.

OBJECTIVES: We developed this study to investigate the association of fibromyalgia with personality traits, controlling for depression and other potential confounders. METHODS: We assessed personality traits with the Cloninger's Temperament and Character Inventory (TCI) in 78 female patients with fibromyalgia and in a control group of 78 subjects without fibromyalgia. The Mini-International Neuropsychiatric Interview was used to assess depression and anxiety diagnoses. To investigate the association between fibromyalgia and the Cloninger's Temperament and Character Inventory we performed unadjusted and adjusted analyses of covariance, using the TCI score as dependent variable and adjusting the model for depression, anxiety and for clinical and socio-demographic variables. We used a backward selection method to choose the final model. RESULTS: In the unadjusted analysis, fibromyalgia was associated with all personality traits, except persistency. After adjusting for depression and anxiety, patients with fibromyalgia presented decreased novelty seeking compared to controls; the differences in other personality traits were no longer significant. Novelty seeking was also correlated with the length of history of fibromyalgia and pain intensity. CONCLUSIONS: Decreased novelty seeking may be a personality trait associated with fibromyalgia. Depression and anxiety should be considered potential confounders in the evaluation of personality traits in this population.

Brain bioenergetic abnormalities have been observed frequently in adults with major depressive disorder (MDD); however, results have been inconsistent regarding whether decreased or increased metabolism was observed. Phosphorus-31 magnetic resonance spectroscopy (31P MRS) allows for the quantification of bioenergetic molecules, containing high-energy phosphates, over the whole brain as well as measuring the differences between gray matter and white matter. We recruited 50 subjects with a current diagnosis of MDD, not currently treated with psychotropic medication, between ages of 18 and 65 (mean+/-SD age: 43.4+/-13.6; 46% female) and 30 healthy volunteers, matched for age and gender (39.0+/-12.5 years of age; 36.6% female). All subjects received a T1 MP-FLASH scan for tissue segmentation followed by 31P MRS, chemical shift imaging scan with 84 voxels of data collected over the entire brain utilizing a dual-tuned, proton-phosphorus coil to minimize subject movement. Phosphocreatine and inorganic phosphate (Pi) varied in opposite directions across gray matter and white matter when MDD subjects were compared with controls. This finding suggests alterations in high-energy phosphate metabolism and regulation of oxidative phosphorylation in MDD patients. In addition, within the MDD group, gray matter Pi, a regulator of oxidative phosphorylation, correlated positively with severity of depression. These data support a model that includes changes in brain bioenergetic function in subjects with major depression.Neuropsychopharmacology advance online publication, 5 October 2016; doi:10.1038/npp.2016.180.

Given the high prevalence of treatment-resistant depression and the long delays in finding effective treatments via trial and error, valid biomarkers of treatment outcome with the ability to guide treatment selection represent one of the most important unmet needs in mood disorders. A large body of research has investigated, for this purpose, biomarkers derived from electroencephalography (EEG), using resting state EEG or evoked potentials. Most studies have focused on specific EEG features (or combinations thereof), whereas more recently machine-learning approaches have been used to define the EEG features with the best predictive abilities without a priori hypotheses. While reviewing these different approaches, we have focused on the predictor characteristics and the quality of the supporting evidence.

We examined the use of near-infrared and red radiation (photobiomodulation, PBM) for treating major depressive disorder (MDD). While still experimental, preliminary data on the use of PBM for brain disorders are promising. PBM is low-cost with potential for wide dissemination; further research on PBM is sorely needed. We found clinical and preclinical studies via PubMed search (2015), using the following keywords: "near-infrared radiation," "NIR," "low-level light therapy," "low-level laser therapy," or "LLLT" plus "depression." We chose clinically focused studies and excluded studies involving near-infrared spectroscopy. In addition, we used PubMed to find articles that examine the link between PBM and relevant biological processes including metabolism, inflammation, oxidative stress, and neurogenesis. Studies suggest the processes aforementioned are potentially effective targets for PBM to treat depression. There is also clinical preliminary evidence suggesting the efficacy of PBM in treating MDD, and comorbid anxiety disorders, suicidal ideation, and traumatic brain injury. Based on the data collected to date, PBM appears to be a promising treatment for depression that is safe and well-tolerated. However, large randomized controlled trials are still needed to establish the safety and effectiveness of this new treatment for MDD.

Approximately one-third of patients with major depressive disorder (MDD) do not respond to existing antidepressants, and those who do generally take weeks to months to achieve a significant effect. There is a clear unmet need for rapidly acting and more efficacious treatments. We will review recent developments in the study of ketamine, an old anaesthetic agent which has shown significant promise as a rapidly acting antidepressant in treatment-resistant patients with unipolar MDD, focusing on clinically important aspects such as dose, route of administration and duration of effect. Additional evidence suggests ketamine may be efficacious in patients with bipolar depression, post-traumatic stress disorder and acute suicidal ideation. We then discuss the safety of ketamine, in which most neuropsychiatric, neurocognitive and cardiovascular disturbances are short lasting; however, the long-term effects of ketamine are still unclear. We finally conclude with important information about ketamine for primary and secondary physicians as evidence continues to emerge for its potential use in clinical settings, underscoring the need for further investigation of its effects.

BACKGROUND: Major depressive disorder is a disabling neuropsychiatric condition that is associated with disrupted functional connectivity across brain networks. The precise nature of altered connectivity, however, remains incompletely understood. The current study was designed to examine the coherence of large-scale connectivity in depression using a recently developed technique termed global brain connectivity. METHODS: A total of 82 subjects, including medication-free patients with major depression (n = 57) and healthy volunteers (n = 25) underwent functional magnetic resonance imaging with resting data acquisition for functional connectivity analysis. Global brain connectivity was computed as the mean of each voxel's time series correlation with every other voxel and compared between study groups. Relationships between global connectivity and depressive symptom severity measured using the Montgomery-Asberg Depression Rating Scale were examined by means of linear correlation. RESULTS: Relative to the healthy group, patients with depression evidenced reduced global connectivity bilaterally within multiple regions of medial and lateral prefrontal cortex. The largest between-group difference was observed within the right subgenual anterior cingulate cortex, extending into ventromedial prefrontal cortex bilaterally (Hedges' g = -1.48, P < 0.000001). Within the depressed group, patients with the lowest connectivity evidenced the highest symptom severity within ventromedial prefrontal cortex (r = -0.47, P = 0.0005). CONCLUSIONS: Patients with major depressive evidenced abnormal large-scale functional coherence in the brain that was centered within the subgenual cingulate cortex, and medial prefrontal cortex more broadly. These data extend prior studies of connectivity in depression and demonstrate that functional disconnection of the medial prefrontal cortex is a key pathological feature of the disorder. Hum Brain Mapp 37:3214-3223, 2016. (c) 2016 Wiley Periodicals, Inc.

PURPOSE: This study aims to determine whether Psychiatric Electroencephalography Evaluation Registry (PEER) Interactive (an objective, adjunctive tool based on a comparison of a quantitative electroencephalogram to an existing registry of patient outcomes) is more effective than the current standard of care in treatment of subjects suffering from depression. PATIENTS AND METHODS: This is an interim report of an ongoing, 2-year prospective, randomized, double blind, controlled study to evaluate PEER Interactive in guiding medication selection in subjects with a primary diagnosis of depression vs standard treatment. Subjects in treatment at two military hospitals were blinded as to study group assignment and their self-report symptom ratings were also blinded. Quick Inventory of Depressive Symptomatology, Self-Report (QIDS-SR16) depression scores were the primary efficacy endpoint. One hundred and fifty subjects received a quantitative electroencephalography exam and were randomized to either treatment as usual or PEER-informed pharmacotherapy. Subjects in the control group were treated according to Veterans Administration/Department of Defense Guidelines, the current standard of care. In the experimental group, the attending physician received a PEER report ranking the subject's likely clinical response to on-label medications. RESULTS: In this post hoc interim analysis subjects were separated into Report Followed and Report Not Followed groups - based on the concordance between their subsequent treatment and PEER medication guidance. We thus evaluated the predictive validity of PEER recommendations. We found significantly greater improvements in depression scores (QIDS-SR16 P<0.03), reduction in suicidal ideation (Concise Health Risk Tracking Scale-SR7 P<0.002), and post-traumatic stress disorder (PTSD) score improvement (PTSD Checklist Military/Civilian P<0.04) for subjects treated with PEER-recommended medications compared to those who did not follow PEER recommendations. CONCLUSION: This interim analysis suggests that an objective tool such as PEER Interactive can help improve medication selection. Consistent with results of earlier studies, it supports the hypothesis that PEER-guided treatment offers distinct advantages over the current standard of care.