Reduced Hedonic Capacity in Major Depressive Disorder: Evidence from a Probabilistic Reward Task

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.Psycholog

Polypharmacy or medication washout: an old tool revisited

There has been a rapid increase in the use of polypharmacy in psychiatry possibly due to the introduction of newer drugs, greater availability of these newer drugs, excessive confidence in clinical trial results, widespread prescribing of psychotropic medications by primary care, and pressure to augment with additional medications for unresolved side effects or greater efficacy. Even the new generation of medications may not hold significant advantages over older drugs. In fact, there may be additional safety risks with polypharmacy being so widespread. Washout, as a clinical tool, is rarely done in medication management today. Studies have shown that augmenting therapy with additional medications resulted in 9.1%–34.1% dropouts due to intolerance of the augmentation, whereas studies of medication washout demonstrated only 5.9%–7.8% intolerance to the washout procedure. These perils justify reconsideration of medication washout before deciding on augmentation. There are unwarranted fears and resistance in the medical community toward medication washout, especially at the moment a physician is trying to decide whether to washout or add more medications to the treatment regimen. However, medication washout provides unique benefits to the physician: it establishes a new baseline of the disorder, helps identify medication efficacy from their adverse effects, and provides clarity of diagnosis and potential reduction of drug treatments, drug interactions, and costs. It may also reduce overall adverse events, not to mention a potential to reduce liability. After washout, physicians may be able to select the appropriate polypharmacy more effectively and safely, if necessary. Washout, while not for every patient, may be an effective tool for physicians who need to decide on whether to add potentially risky polypharmacy for a given patient. The risks of washout may, in some cases, be lower and the benefits may be clearly helpful for diagnosis, understanding medication effects, the doctor/patient relationship, and safer use of polypharmacy if indicated

Euthymic Patients with Bipolar Disorder Show Decreased Reward Learning in a Probabilistic Reward Task

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.Psycholog

Major depression in patients with non-cardiac chest pain: Who is going to treat?

OBJETIVO: Investigar a presença de transtornos psiquiátricos em pacientes com dor torácica de origem não cardíaca que não respondem aos tratamentos regulares. MÉTODO: Dezoito pacientes com dor torácica sem origem cardíaca e considerados por seus clínicos como não respondentes aos tratamentos regulares instituídos foram avaliados por um psiquiatra treinado. As entrevistas foram realizadas com base no Present State Examination e os diagnósticos psiquiá-tricos, de acordo com os critérios do Manual de Diagnóstico e Estatística da Associação Psiquiátrica Americana, 3ª Edição Revisada (DSM-III-R). RESULTADOS: Depressão maior no momento da avaliação foi diagnosticada em 6 (30%) pacientes, somatização em 1 (6%) e transtorno do pânico em 1 (6%) paciente. Sete pacientes estavam recebendo antidepressivos tricíclicos com doses < 75 mg/dia. CONCLUSÕES: A baixa dose de ADTs usadas para o tratamento da dor nesses pacientes pode ter melhorado parcialmente os sintomas depressivos, tornando mais difíceis o diagnóstico e o tratamento apropriado(s) da depressão e, assim, contribuindo para a persistência da dor e outras queixas. As futuras pesquisas deverão focalizar a eficácia do tratamento da depressão nesses pacientes e o impacto deste no alívio da dor torácica não cardíaca.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 > 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

Recognition of Depressive Symptoms by Physicians

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

The association of major depressive episode and personality traits in patients with fibromyalgia

INTRODUCTION: Personality traits have been associated with primary depression. However, it is not known whether this association takes place in the case of depression comorbid with fibromyalgia. OBJECTIVE: The authors investigated the association between a current major depressive episode and temperament traits (e.g., harm avoidance). METHOD: A sample of 69 adult female patients with fibromyalgia was assessed with the Temperament and Character Inventory. Psychiatric diagnoses were assessed with the Mini-International Neuropsychiatric Interview severity of depressive symptomatology with the Beck Depression Inventory, and anxiety symptomatology with the IDATE-state and pain intensity with a visual analog scale. RESULTS: A current major depressive episode was diagnosed in 28 (40.5%) of the patients. They presented higher levels of harm avoidance and lower levels of cooperativeness and self-directedness compared with non-depressed patients, which is consistent with the Temperament and Character Inventory profile of subjects with primary depression. However, in contrast to previous results in primary depression, no association between a major depressive episode and self-transcendence was found. CONCLUSIONS: The results highlight specific features of depression in fibromyalgia subjects and may prove important for enhancing the diagnosis and prognosis of depression in fibromyalgia patients

Psychophysiological treatment outcomes: Corticotropin-releasing factor type 1 receptor antagonist increases inhibition of fear-potentiated startle in PTSD patients.

After exposure to a traumatic event, a subset of people develop post-traumatic stress disorder (PTSD). One of the key deficits in PTSD is regulation of fear, and impaired inhibition of fear-potentiated startle (FPS) has been identified as a potential physiological biomarker specific to PTSD. As part of a larger clinical trial, this study investigated the effects of a CRF receptor 1 antagonist, GSK561679, on inhibition of fear-potentiated startle during a conditional discrimination fear-conditioning paradigm, termed AX+/BX-. Prior research using this paradigm has demonstrated deficits in inhibition of conditioned fear in several PTSD populations. The randomized, double-blind, placebo-controlled clinical trial compared fear inhibition between female PTSD participants taking 350&nbsp;mg/day GSK561679 (n&nbsp;=&nbsp;47 pre- and 29 post-treatment) and patients taking a placebo pill (n&nbsp;=&nbsp;52 pre- and 30 post-treatment) daily for 6&nbsp;weeks. There was no significant difference between the two groups in their acquisition of fear or discrimination between threat and safety cues, and no pre-post-treatment effect on these measures. However, there was a significant effect of treatment on inhibition of FPS during the AB trials in the AX+/BX- transfer test (p&nbsp;&lt;&nbsp;0.05). While all PTSD participants showed typical impairments in fear inhibition prior to treatment, GSK561679 enhanced fear inhibition post-treatment, independent of clinical effects. The current study suggests that CRF receptor 1 antagonism may have specific effects within neural circuitry mediating fear inhibition responses, but not overall symptom presentation, in PTSD