Faculty Bibliography

OBJECTIVE: Major depressive disorder is characterized by impaired reward processing, possibly due to dysfunction in the basal ganglia. However, few neuroimaging studies of depression have distinguished between anticipatory and consummatory phases of reward processing. Using functional MRI (fMRI) and a task that dissociates anticipatory and consummatory phases of reward processing, the authors tested the hypothesis that individuals with major depression would show reduced reward-related responses in basal ganglia structures. METHOD: A monetary incentive delay task was presented to 30 unmedicated individuals with major depressive disorder and 31 healthy comparison subjects during fMRI scanning. Whole-brain analyses focused on neural responses to reward-predicting cues and rewarding outcomes (i.e., monetary gains). Secondary analyses focused on the relationship between anhedonic symptoms and basal ganglia volumes. RESULTS: Relative to comparison subjects, participants with major depression showed significantly weaker responses to gains in the left nucleus accumbens and the caudate bilaterally. Group differences in these regions were specific to rewarding outcomes and did not generalize to neutral or negative outcomes, although relatively reduced responses to monetary penalties in the major depression group emerged in other caudate regions. By contrast, evidence for group differences during reward anticipation was weaker, although participants with major depression showed reduced activation to reward cues in a small sector of the left posterior putamen. In the major depression group, anhedonic symptoms and depression severity were associated with reduced caudate volume bilaterally. CONCLUSIONS: These results suggest that basal ganglia dysfunction in major depression may affect the consummatory phase of reward processing. Additionally, morphometric results suggest that anhedonia in major depression is related to caudate volume.

BACKGROUND: Little is known about the treatment of depression in older patients with heart failure. This study was developed to investigate the effectiveness of antidepressant treatment for major depressive disorder (MDD) in the elderly with heart failure. METHODS: We enrolled 72 older outpatients with ejection fraction <50 and diagnosed with MDD by the structured clinical interview for DSM-IV. Thirty-seven patients, 19 on citalopram and 18 on placebo, initiated an 8-week double-blind treatment phase. Measurements were performed with the 31-item Hamilton Rating Scale for Depression (Ham-D-31), the Montgomery-Asberg rating scale (MADRS) and the Systematic Assessment for Treatment Emergent Effects (SAFTEE). A psychiatrist followed up the patients weekly, performing a consultation for about 20 min to field complaints after the measurements. RESULTS: A trend toward superiority of citalopram over placebo in reducing depression was observed in MADRS scores (15.05+9.74 vs 9.44+9.25, P=.082) but not on HAM-D scores. The depressive symptomatology significantly decreased in both groups (P < .001). The high rate of placebo response during the double-blind phase (56.3%) led us to conclude the study at the interim analysis with 37 patients. CONCLUSION: Citalopram treatment of MDD in older patients with heart failure is well-tolerated with low rates of side effects, but was not significantly more effective than placebo in the treatment of depression. Weekly psychiatric follow-up including counseling may contribute to the improvement of depression in this population. Scales weighted on psychological symptoms such as the MADRS are possibly better suited to measure depression severity and improvement in patients with heart failure.

Objective: To investigate the presence of psychiatric disorders in patients with chest pain not responsive to treatment. Method: We evaluated 18 patients judged by their physicians to have a chest pain not responsive to usual treatment, which included anti-pain medicines and investigation and treatment of possible etiological causes such as coronary artery disease, and gastroesophageal reflux disease. A psychiatrist interviewed the patients using the Present State Examination and made the diagnosis based on the DSM-III-R criteria. Current major depression was diagnosed in 6 (30%) patients, somatization in 1 (6%) and panic disorder in 1 (6%) patient. Seven patients were receiving tricyclics antidepressant with doses &gt;= 75 mg/day. Discussion: Patients were receiving doses of tricyclics antidepressants efficacious for pain but not for major depression. It is possible that the low dose of antidepressants used to treat pain may partially ameliorate depressive symptoms, making the appropriate diagnosis and treatment of major depression even more difficult, consequently contributing to the persistence of pain and other complains. Considering the wide alternatives to effectively treat depression, a focus on detection and treatment of major depression in patients with chest pain is warranted by clinicians and researchers.

BACKGROUND: Many subjects with bipolar disorder experience significant cognitive dysfunction, even when euthymic, but few studies assess biological correlates of or treatment strategies for cognitive dysfunction. METHOD: Nineteen subjects with bipolar disorder in remission, who reported subjective cognitive deficits, were treated with open-label galantamine-ER 8-24 mg/day for 4 months. Ten healthy volunteers matched for age and gender were also assessed. Mood and subjective cognitive questionnaires were administered monthly. At the beginning and the end of the trial all subjects were administered neuropsychological tests, including tests of attention (Conners CPT) and episodic memory (CVLT). Bipolar subjects underwent proton magnetic resonance spectroscopy (1H-MRS) measurements before and after treatment, healthy volunteers completed baseline 1H-MRS. We acquired 1H-MRS data at 4.0 T from voxels centered on the left and right hippocampus to measure hippocampal N-acetyl aspartate (NAA, a measure of neuronal viability) and choline containing compounds (Cho, a marker of lipid metabolism and membrane turn-over). RESULTS: Compared to healthy volunteers, bipolar subjects had higher baseline subjective cognitive deficits and lower scores on objective tests of attention (Conner's CPT) and verbal episodic memory (CVLT). After treatment, bipolar subjects experienced significant improvement of subjective cognitive scores and on objective tests of attention (Conner's CPT) and verbal episodic memory (CVLT). In the left hippocampus NAA increased and choline (Cho) decreased in bipolar subjects during treatment. CONCLUSION: Bipolar subjects had cognitive dysfunction; treatment with Galantamine-ER was associated with improved cognition and with increases in neuronal viability and normalization of lipid membrane metabolism in the left hippocampus. This study was registered on ClinicalTrials.gov (NCT00181636).

OBJECTIVE: To investigate the recognition of depressive symptoms of major depressive disorder (MDD) by general practitioners. INTRODUCTION: MDD is underdiagnosed in medical settings, possibly because of difficulties in the recognition of specific depressive symptoms. METHODS: A cross-sectional study of 316 outpatients at their first visit to a teaching general hospital. We evaluated the performance of 19 general practitioners using Primary Care Evaluation of Mental Disorders (PRIME-MD) to detect depressive symptoms and compared them to 11 psychiatrists using Structured Clinical Interview Axis I Disorders, Patient Version (SCID I/P). We measured likelihood ratios, sensitivity, specificity, and false positive and false negative frequencies. RESULTS: The lowest positive likelihood ratios were for psychomotor agitation/retardation (1.6) and fatigue (1.7), mostly because of a high rate of false positive results. The highest positive likelihood ratio was found for thoughts of suicide (8.5). The lowest sensitivity, 61.8%, was found for impaired concentration. The sensitivity for worthlessness or guilt in patients with medical illness was 67.2% (95% CI, 57.4-76.9%), which is significantly lower than that found in patients without medical illness, 91.3% (95% CI, 83.2-99.4%). DISCUSSION: Less adequately identified depressive symptoms were both psychological and somatic in nature. The presence of a medical illness may decrease the sensitivity of recognizing specific depressive symptoms. CONCLUSIONS: Programs for training physicians in the use of diagnostic tools should consider their performance in recognizing specific depressive symptoms. Such procedures could allow for the development of specific training to aid in the detection of the most misrecognized depressive symptoms.

BACKGROUND: We have recently developed the Massachusetts General Hospital Cognitive and Physical Functioning Questionnaire (CPFQ), a brief scale to measure cognitive and executive dysfunction in mood and anxiety disorders, and we here report on its reliability and validity. METHODS: The internal consistency of the CPFQ was assessed by computing Cronbach's coefficient alpha based upon the average intercorrelation of the 7 items of the CPFQ in a sample of depressed outpatients and by factor analyzing data from the same sample to confirm that the scale is unifactorial and measuring a single construct. Test-retest reliability of the CPFQ was assessed in a different sample of depressed outpatients by computing Pearson's correlation coefficient between pretreatment screening scores and pretreatment baseline scores. Sensitivity to change of the CPFQ was assessed by computing the dependent t test for the subjects in the active treatment condition in the second sample of depressed outpatients. Finally, convergent validity for the CPFQ was assessed in two different ways. RESULTS: We found that the CPFQ is a unifactorial scale, with strong internal consistency. It has good temporal stability as indicated by high test-retest reliability. The CPFQ was also found to be sensitive to change with treatment and displayed convergent validity by significant correlations with other measures of sleepiness, fatigue, apathy and neuropsychological functioning. Although, as expected, the CPFQ was significantly correlated with a measure of depression, the moderate correlation (r approximately 0.30) indicates that the CPFQ is measuring a different construct. CONCLUSION: In summary, the CPFQ is a unifactorial scale, with strong internal consistency, good temporal stability and sensitivity to change with treatment. Further studies will be needed to assess the validity and reliability of this instrument in other psychiatric and neuropsychiatric conditions associated with cognitive dysfunction.

OBJECTIVE: Anhedonia, the lack of reactivity to pleasurable stimuli, is a cardinal feature of depression that has received renewed interest as a potential endophenotype of this debilitating disease. The goal of the present study was to test the hypothesis that individuals with major depression are characterized by blunted reward responsiveness, particularly when anhedonic symptoms are prominent. METHODS: A probabilistic reward task rooted within signal-detection theory was utilized to objectively assess hedonic capacity in 23 unmedicated subjects meeting DSM-IV criteria for major depressive disorder (MDD) and 25 matched control subjects recruited from the community. Hedonic capacity was defined as reward responsiveness - i.e., the participants' propensity to modulate behavior as a function of reward. RESULTS: Compared to controls, MDD subjects showed significantly reduced reward responsiveness. Trial-by-trial probability analyses revealed that MDD subjects, while responsive to delivery of single rewards, were impaired at integrating reinforcement history over time and expressing a response bias toward a more frequently rewarded cue in the absence of immediate reward. This selective impairment correlated with self-reported anhedonic symptoms, even after considering anxiety symptoms and general distress. CONCLUSIONS: These findings indicate that MDD is characterized by an impaired tendency to modulate behavior as a function of prior reinforcements, and provides initial clues about which aspects of hedonic processing might be dysfunctional in depression.

The structural effects of cocaine on neural systems mediating cognition and motivation are not well known. By comparing the thickness of neocortical and paralimbic brain regions between cocaine-dependent and matched control subjects, we found that four of 18 a priori regions involved with executive regulation of reward and attention were significantly thinner in addicts. Correlations were significant between thinner prefrontal cortex and reduced keypresses during judgment and decision making of relative preference in addicts, suggesting one basis for restricted behavioral repertoires in drug dependence. Reduced effortful attention performance in addicts also correlated with thinner paralimbic cortices. Some thickness differences in addicts were correlated with cocaine use independent of nicotine and alcohol, but addicts also showed diminished thickness heterogeneity and altered hemispheric thickness asymmetry. These observations suggest that brain structure abnormalities in addicts are related in part to drug use and in part to predisposition toward addiction.

BACKGROUND: Bipolar disorder (BPD) features cycling mood states ranging from depression to mania with intermittent phases of euthymia. Bipolar disorder subjects often show excessive goal-directed and pleasure-seeking behavior during manic episodes and reduced hedonic capacity during depressive episodes, indicating that BPD might involve altered reward processing. Our goal was to test the hypothesis that BPD is characterized by impairments in adjusting behavior as a function of prior reinforcement history, particularly in the presence of residual anhedonic symptoms. METHODS: Eighteen medicated BPD subjects and 25 demographically matched comparison subjects performed a probabilistic reward task. To identify putative dysfunctions in reward processing irrespective of mood state, primary analyses focused on euthymic BPD subjects (n = 13). With signal-detection methodologies, response bias toward a more frequently rewarded stimulus was used to objectively assess the participants' propensity to modulate behavior as a function of reinforcement history. RESULTS: Relative to comparison subjects, euthymic BPD subjects showed a reduced and delayed acquisition of response bias toward the more frequently rewarded stimulus, which was partially due to increased sensitivity to single rewards of the disadvantageous stimulus. Analyses considering the entire BPD sample revealed that reduced reward learning correlated with self-reported anhedonic symptoms, even after adjusting for residual manic and anxious symptoms and general distress. CONCLUSIONS: The present study provides preliminary evidence indicating that BPD, even during euthymic states, is characterized by dysfunctional reward learning in situations requiring integration of reinforcement information over time and thus offers initial insights about the potential source of dysfunctional reward processing in this disorder.