Faculty Bibliography

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.

BACKGROUND: Poststroke depressive symptoms have prospectively predicted impairment of health-related quality of life (HRQOL). However, it is not known whether such predictive effect is independent of HRQOL at 1 month after stroke. This study aimed to investigate the impact of depressive symptoms at 1 and 3 months after stroke on the 3-month poststroke HRQOL and to investigate the influence of the HRQOL measured at 1 month after stroke on these relationships. METHODS: We prospectively evaluated 67 patients at 1 and 3 months after a first-ever ischemic stroke from 106 eligible patients who have been consecutively admitted to the neurology ward of a teaching hospital. A psychiatrist assessed the presence of depressive symptoms using the 31-item version of the Hamilton Rating Scale for Depression and the HRQOL was assessed with the 36-item Short-Form Health Survey from the Medical Outcomes Study. We used linear regression to measure the impact of depressive symptoms, HRQOL at 1 month, and potential confounders on HRQOL at 3 months. RESULTS: We found an association between depressive symptoms at 1 month and HRQOL at 3 months after the stroke; however, this association was not significant when adjusting for the 1 month poststroke HRQOL. Depressive symptoms at 3 months were associated with HRQOL at 3 months after stroke, independently of the poststroke HRQOL at 1 month and potential confounders. CONCLUSIONS: Current depressive symptoms at 3 months are important for HRQOL at 3 months after stroke; however, regarding the prospective prediction, HRQOL at 1 month is the most relevant factor.

BACKGROUND: Anhedonia constitutes a coherent construct, with neural correlates and negative clinical impact, independent of depression. However, little is known about the neural correlates of anhedonia in stroke patients. In this study, we investigated the association of post-stroke anhedonia with salivary cortisol levels and stroke location and volume. PATIENTS AND METHODS: A psychiatrist administered the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition to identify anhedonia in 36 inpatients, without previous depression, consecutively admitted in a neurology clinic in the first month after a first-ever ischemic stroke. Salivary cortisol levels were assessed in the morning, evening, and after a dexamethasone suppression test. We used magnetic resonance imaging and a semi-automated brain morphometry method to assess stroke location, and the MRIcro program according to the Brodmann Map to calculate the lesion volume. RESULTS: Patients with anhedonia had significantly larger diurnal variation (P-value =0.017) and higher morning levels of salivary cortisol (1,671.9+/-604.0 ng/dL versus 1,103.9+/-821.9 ng/dL; P-value =0.022), and greater stroke lesions in the parahippocampal gyrus (Brodmann area 36) compared to those without anhedonia (10.14 voxels; standard deviation +/-17.72 versus 0.86 voxels; standard deviation +/-4.64; P-value =0.027). The volume of lesion in the parahippocampal gyrus (Brodmann area 36) was associated with diurnal variation of salivary cortisol levels (rho=0.845; P-value =0.034) only in anhedonic patients. CONCLUSION: Our findings suggest that anhedonia in stroke patients is associated with the volume of stroke lesion in the parahippocampal gyrus and with dysfunction of the hypothalamic-pituitary-adrenal axis.

Transcranial near-infrared radiation (NIR) is an innovative treatment for major depressive disorder (MDD), but clinical evidence for its efficacy is limited. Our objective was to investigate the tolerability and efficacy of NIR in patients with MDD. We conducted a proof of concept, prospective, double-blind, randomized study of 6 sessions of NIR versus sham treatment for patients with MDD, using a crossover design. Four patients with MDD with mean age 47 +/- 14 (SD) years (1 woman and 3 men) were exposed to irradiance of 700 mW/cm(2) and a fluence of 84 J/cm(2) for a total NIR energy of 2.40 kJ delivered per session for 6 sessions. Baseline mean HAM-D17 scores decreased from 19.8 +/- 4.4 (SD) to 13 +/- 5.35 (SD) after treatment (t = 7.905; df = 3; P = 0.004). Patients tolerated the treatment well without any serious adverse events. These findings confirm and extend the preliminary data on NIR as a novel intervention for patients with MDD, but further clinical trials are needed to better understand the efficacy of this new treatment. This trial is registered with ClinicalTrials.gov NCT01538199.

BACKGROUND: The N-methyl-D-aspartate glutamate receptor antagonist ketamine, delivered via an intravenous route, has shown rapid antidepressant effects in patients with treatment-resistant depression. The current study was designed to test the safety, tolerability, and efficacy of intranasal ketamine in patients with depression who had failed at least one prior antidepressant trial. METHODS: In a randomized, double-blind, crossover study, 20 patients with major depression were randomly assigned, and 18 completed 2 treatment days with intranasal ketamine hydrochloride (50 mg) or saline solution. The primary efficacy outcome measure was change in depression severity 24 hours after ketamine or placebo, measured using the Montgomery-Asberg Depression Rating Scale. Secondary outcomes included persistence of benefit, changes in self-reports of depression, changes in anxiety, and proportion of responders. Potential psychotomimetic, dissociative, hemodynamic, and general adverse effects associated with ketamine were also measured. RESULTS: Patients showed significant improvement in depressive symptoms at 24 hours after ketamine compared to placebo (t = 4.39, p < .001; estimated mean Montgomery-Asberg Depression Rating Scale score difference of 7.6 +/- 3.7; 95% confidence interval, 3.9-11.3). Response criteria were met by 8 of 18 patients (44%) 24 hours after ketamine administration compared with 1 of 18 (6%) after placebo (p = .033). Intranasal ketamine was well tolerated with minimal psychotomimetic or dissociative effects and was not associated with clinically significant changes in hemodynamic parameters. CONCLUSIONS: This study provides the first controlled evidence for the rapid antidepressant effects of intranasal ketamine. Treatment was associated with minimal adverse effects. If replicated, these findings may lead to novel approaches to the pharmacologic treatment of patients with major depression.