Faculty Bibliography

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-Asberg 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.

OBJECTIVES: Treatment-resistant depression is a common clinical occurrence among patients with major depressive disorder (MDD), but its neurobiology is poorly understood. We used data collected as part of routine clinical care to study white matter integrity of the brain's limbic system and its association to treatment response. METHODS: Electronic medical records of multiple large New England hospitals were screened for patients with an MDD billing diagnosis, and natural language processing was subsequently applied to find those with concurrent diffusion-weighted images, but without any diagnosed brain pathology. Treatment outcome was determined by review of clinical charts. MDD patients (n = 29 non-remitters, n = 26 partial-remitters, and n = 37 full-remitters), and healthy control subjects (n = 58) were analyzed for fractional anisotropy (FA) of the fornix and cingulum bundle. RESULTS: Failure to achieve remission was associated with lower FA among MDD patients, statistically significant for the medial body of the fornix. Moreover, global and regional-selective age-related FA decline was most pronounced in patients with treatment-refractory, non-remitted depression. CONCLUSIONS: These findings suggest that specific brain microstructural white matter abnormalities underlie persistent, treatment-resistant depression. They also demonstrate the feasibility of investigating white matter integrity in psychiatric populations using legacy data.

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.

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.

Major depressive disorder (MDD) is common. Despite numerous available treatments, many individuals fail to improve clinically. MDD continues to be diagnosed exclusively via behavioral rather than biological methods. Biomarkers-which include measurements of genes, proteins, and patterns of brain activity-may provide an important objective tool for the diagnosis of MDD or in the rational selection of treatments. Proteomic analysis and validation of its results as biomarkers is less explored than other areas of biomarker research in MDD. Mass spectrometry (MS) is a comprehensive, unbiased means of proteomic analysis, which can be complemented by directed protein measurements, such as Western Blotting. Prior studies have focused on MS analysis of several human biomaterials in MDD, including human post-mortem brain, cerebrospinal fluid (CSF), blood components, and urine. Further studies utilizing MS and proteomic analysis in MDD may help solidify and establish biomarkers for use in diagnosis, identification of new treatment targets, and understanding of the disorder. The ultimate goal is the validation of a biomarker or a biomarker signature that facilitates a convenient and inexpensive predictive test for depression treatment response and helps clinicians in the rational selection of next-step treatments.

The depression-executive dysfunction syndrome, a late-onset depression of vascular origin with executive dysfunction and psychomotor retardation, has also been described after stroke. We verified whether this syndrome also occurs in nonelderly stroke patients by investigating the association between domains of depressive symptoms with executive functions in 87 first-ever ischemic stroke patients. The retardation domain of the 31-item Hamilton Rating Scale for Depression was associated with decreased performance on verbal fluency (assessed with FAS). The association was maintained for younger patients (aged <60 years) after adjusting for confounders. This result supports the clinical presentation of depression-executive dysfunction syndrome in younger stroke patients. Confirmation of this finding, its neural correlates, and clinical implication deserve further investigation.

OBJECTIVE Bipolar disorder is a severe, chronic mental illness with a high incidence of medical and psychological comorbidities that make treatment and prevention of future episodes challenging. This study investigated the use of services among outpatients with bipolar disorder to further understanding of how to maximize and optimize personalization and accessibility of services for this difficult-to-treat population. METHODS The Lithium Treatment-Moderate Dose Use Study (LiTMUS) was a six-month multisite, comparative effectiveness trial that randomly assigned 283 individuals to receive lithium plus optimized care-defined as personalized, guideline-informed care-or optimized care without lithium. Relationships between treatment service utilization, captured by the Cornell Service Index, and demographic and illness characteristics were examined with generalized linear marginal models. RESULTS Analyses with complete data (week 12, N=246; week 24, N=236) showed that increased service utilization was related to more severe bipolar disorder symptoms, physical side effects, and psychiatric and general medical comorbidities. Middle-aged individuals and those living in the United States longer tended to use more services than younger individuals or recent immigrants, respectively. CONCLUSIONS These data suggest that not all individuals with bipolar disorder seek treatment services at the same rate. Instead, specific clinical or demographic features may affect the degree to which one seeks treatment, conveying clinical and public health implications and highlighting the need for specific approaches to correct such discrepancies. Future research is needed to elucidate potential moderators of service utilization in bipolar disorder to ensure that those most in need of additional services utilize them.

This paper describes the development and use of the Medication Recommendation Tracking Form (MRTF), a novel method for capturing physician prescribing behavior and clinical decision making. The Bipolar Trials Network developed and implemented the MRTF in a comparative effectiveness study for bipolar disorder (LiTMUS). The MRTF was used to assess the frequency, types, and reasons for medication adjustments. Changes in treatment were operationalized by the metric Necessary Clinical Adjustments (NCA), defined as medication adjustments to reduce symptoms, optimize treatment response and functioning, or to address intolerable side effects. Randomized treatment groups did not differ in rates of NCAs, however, responders had significantly fewer NCAs than non-responders. Patients who had more NCAs during their previous visit had significantly lower odds of responding at the current visit. For each one-unit increase in previous CGI-BP depression score and CGI-BP overall severity score, patients had an increased NCA rate of 13% and 15%, respectively at the present visit. Ten-unit increases in previous Montgomery Asberg Depression Rating Scale (MADRS) and Young Mania Rating Scale (YMRS) scores resulted in an 18% and 14% increase in rates of NCAs, respectively. Patients with fewer NCAs had increased quality of life and decreased functional impairment. The MRTF standardizes the reporting and rationale for medication adjustments and provides an innovative metric for clinical effectiveness. As the first tool in psychiatry to track the types and reasons for medication changes, it has important implications for training new clinicians and examining clinical decision making. (ClinicalTrials.gov number NCT00667745).