Faculty Bibliography

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).

OBJECTIVE: Ketamine, a glutamate N-methyl-d-aspartate (NMDA) receptor antagonist, has shown rapid antidepressant effects, but small study groups and inadequate control conditions in prior studies have precluded a definitive conclusion. The authors evaluated the rapid antidepressant efficacy of ketamine in a large group of patients with treatment-resistant major depression. METHOD: This was a two-site, parallel-arm, randomized controlled trial of a single infusion of ketamine compared to an active placebo control condition, the anesthetic midazolam. Patients with treatment-resistant major depression experiencing a major depressive episode were randomly assigned under double-blind conditions to receive a single intravenous infusion of ketamine or midazolam in a 2:1 ratio (N=73). The primary outcome was change in depression severity 24 hours after drug administration, as assessed by the Montgomery-Asberg Depression Rating Scale (MADRS). RESULTS: The ketamine group had greater improvement in the MADRS score than the midazolam group 24 hours after treatment. After adjustment for baseline scores and site, the MADRS score was lower in the ketamine group than in the midazolam group by 7.95 points (95% confidence interval [CI], 3.20 to 12.71). The likelihood of response at 24 hours was greater with ketamine than with midazolam (odds ratio, 2.18; 95% CI, 1.21 to 4.14), with response rates of 64% and 28%, respectively. CONCLUSIONS: Ketamine demonstrated rapid antidepressant effects in an optimized study design, further supporting NMDA receptor modulation as a novel mechanism for accelerated improvement in severe and chronic forms of depression. More information on response durability and safety is required before implementation in clinical practice.

RATIONALE: The N-methyl-D-aspartate (NMDA) glutamate receptor antagonist ketamine has demonstrated rapid antidepressant effects in patients with treatment-resistant depression (TRD). Despite the promise of a novel and urgently needed treatment for refractory depression, concerns regarding potential adverse neurocognitive effects of ketamine remain. OBJECTIVES: Although extensive research has been conducted in healthy volunteers, there is a paucity of studies examining the neurocognitive effects of ketamine in depressed patients. Therefore, the aims of the current study were to characterize the relationship between baseline neurocognition and antidepressant response to ketamine, measure the acute impact of ketamine on neurocognition, and investigate the relationship between acute neurocognitive effects of ketamine and antidepressant response. METHODS: Neurocognitive functioning was assessed in 25 patients with TRD using a comprehensive battery: estimated premorbid intelligence quotient (IQ), current IQ, and tests from the MATRICS Consensus Cognitive Battery (MCCB). A subset of the MCCB was repeated immediately following a 40-min intravenous infusion of ketamine (0.5 mg/kg). RESULTS: Patients who responded to ketamine 24 h following treatment had poorer baseline neurocognitive performance relative to nonresponders and, in particular, slower processing speed (F = 8.42; df = 23; p = 0.008). Ketamine was associated with selective impairments in memory recall, and the degree of cognitive change carried negative prognostic significance (e.g., negative cognitive effects immediately after ketamine predicted lower response rate at 24 h; Fisher's exact test two-sided p = 0.027). CONCLUSIONS: Taken together, our findings suggest a potential baseline neurocognitive predictor of ketamine response and an inverse relationship between the cognitive effects of ketamine and antidepressant efficacy.

BACKGROUND: Ketamine is reported to have rapid antidepressant effects; however, there is limited understanding of the time-course of ketamine effects beyond a single infusion. A previous report including 10 participants with treatment-resistant major depression (TRD) found that six ketamine infusions resulted in a sustained antidepressant effect. In the current report, we examined the pattern and durability of antidepressant effects of repeated ketamine infusions in a larger sample, inclusive of the original. METHODS: Participants with TRD (n = 24) underwent a washout of antidepressant medication followed by a series of up to six IV infusions of ketamine (.5 mg/kg) administered open-label three times weekly over a 12-day period. Participants meeting response criteria were monitored for relapse for up to 83 days from the last infusion. RESULTS: The overall response rate at study end was 70.8%. There was a large mean decrease in Montgomery-Asberg Depression Rating Scale score at 2 hours after the first ketamine infusion (18.9 +/- 6.6, p < .001), and this decrease was largely sustained for the duration of the infusion period. Response at study end was strongly predicted by response at 4 hours (94% sensitive, 71% specific). Among responders, median time to relapse after the last ketamine infusion was 18 days. CONCLUSIONS: Ketamine was associated with a rapid antidepressant effect in TRD that was predictive of a sustained effect. Future controlled studies will be required to identify strategies to maintain an antidepressant response among patients who benefit from a course of ketamine.

BACKGROUND: Multiple treatments for patients with major depressive disorder (MDD) have demonstrated efficacy, but up to one-third of individuals with MDD do not achieve symptomatic remission despite various interventions. Existing augmentation or combination strategies can have substantial safety concerns that may limit their application. METHOD: This study investigated the antidepressant efficacy of a flexible dose of the dopamine agonist pramipexole as an adjunct to standard antidepressant treatment in an 8-week, randomized, double-blind, placebo-controlled trial conducted in a tertiary-level depression center. We randomized 60 outpatients (aged 18 to 75 years) with treatment-resistant nonpsychotic MDD (diagnosed according to DSM-IV) to either pramipexole (n = 30) or placebo (n = 30). Treatment resistance was defined as continued depression (Montgomery-Asberg Depression Rating Scale [MADRS] score >/= 18) despite treatment with at least 1 prior antidepressant in the current depressive episode. Patients were recruited between September 2005 and April 2008. The primary outcome measure was the MADRS score. RESULTS: The analyses that used a mixed-effects linear regression model indicated a modest but statistically significant benefit for pramipexole (P = .038). The last-observation-carried-forward analyses indicated that 40% and 33% of patients randomized to augmentation with pramipexole achieved response (chi(2) = 1.2, P = .27) and remission (chi(2) = 0.74, P = .61), respectively, compared to 27% and 23% with placebo; however, those differences were not statistically significant. Augmentation with pramipexole was well-tolerated, with no serious adverse effects identified. CONCLUSION: For patients who have failed to respond to standard antidepressant therapies, pramipexole is a safe and potentially efficacious augmentation strategy. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00231959.