A randomized, placebo-controlled pilot trial of the delta opioid receptor agonist AZD2327 in anxious depression.

Rationale: Patients with anxious major depressive disorder (AMDD) have more severe symptoms and poorer treatment response than patients with non-AMDD. Increasing evidence implicates the endogenous opioid system in the pathophysiology of depression. AZD2327 is a selective delta opioid receptor (DOR) agonist with anxiolytic and antidepressant activity in animal models.

Ethnic differences in physiological responses to fear conditioned stimuli.

The idea that emotional expression varies with ethnicity is based largely on questionnaires and behavioral observations rather than physiological measures. We therefore compared the skin conductance responses (SCR) of Hispanic (Puerto Rican) and White non-Hispanic subjects in a fear conditioning and fear extinction task. Subjects were recruited from two sites: San Juan, Puerto Rico (PR), and Boston, Massachusetts (MA), using identical methods.

Major depression is not associated with blunting of aversive responses; evidence for enhanced anxious anticipation.

According to the emotion-context insensitivity (ECI) hypothesis, major depressive disorder (MDD) is associated with a diminished ability to react emotionally to positive stimuli and with blunting of defensive responses to threat. That defensive responses are blunted in MDD seems inconsistent with the conceptualization and diagnostic nosology of MDD. The present study tested the ECI hypothesis in MDD using a threat of shock paradigm.

Combining a dopamine agonist and selective serotonin reuptake inhibitor for the treatment of depression: a double-blind, randomized pilot study.

Background: Antidepressants that act on two or more amine neurotransmitters may confer higher remission rates when first-line agents affecting a single neurotransmitter have failed. Pramipexole, a dopamine agonist, has antidepressant effects in patients with major depressive disorder (MDD). This pilot study examined the efficacy and safety of combination therapy with pramipexole and the selective serotonin reuptake inhibitor (SSRI) escitalopram in MDD.

A randomized trial of a low-trapping nonselective N-methyl-D-aspartate channel blocker in major depression.

Background: The high-affinity N-methyl-D-aspartate (NMDA) antagonist ketamine exerts rapid antidepressant effects but has psychotomimetic properties. AZD6765 is a low-trapping NMDA channel blocker with low rates of associated psychotomimetic effects. This study investigated whether AZD6765 could produce rapid antidepressant effects in subjects with treatment-resistant major depressive disorder (MDD).

Correlations between psychological tests and physiological responses during fear conditioning and renewal.

Background: Anxiety disorders are characterized by specific emotions, thoughts and physiological responses. Little is known, however, about the relationship between psychological/personality indices of anxiety responses to fear stimuli.

Methods: We studied this relationship in healthy subjects by comparing scores on psychological and personality questionnaires with results of an experimental fear conditioning paradigm using a visual conditioned stimulus (CS).

Family history of alcohol dependence and antidepressant response to an N-methyl-D-aspartate antagonist in bipolar depression.

Objectives: Both ketamine and ethanol are N-methyl-d-aspartate (NMDA) receptor antagonists. Ketamine has rapid antidepressant properties in major depressive disorder (MDD) as well as bipolar depression. In individuals with MDD, a positive family history of alcohol dependence (FHP) was associated with greater improvement in depressive symptoms after ketamine administration compared to individuals whose family history of alcohol dependence was negative (FHN).

Course of improvement in depressive symptoms to a single intravenous infusion of ketamine vs add-on riluzole: results from a 4-week, double-blind, placebo-controlled study.

The N-methyl-D-aspartate antagonist ketamine has rapid antidepressant effects in patients with treatment-resistant major depression (TRD); these effects have been reported to last for 1 week in some patients. However, the extent and duration of this antidepressant effect over longer periods has not been well characterized under controlled conditions. Riluzole, a glutamatergic modulator with antidepressant and synaptic plasticity-enhancing effects, could conceivably be used to promote the antidepressant effects of ketamine.