Predicting Incident Treatment-Resistant Depression: A Model Designed for Health Systems of Care.

Background: Major depressive disorder (MDD) is a prevalent and debilitating condition. While numerous treatment options are available, low treatment response and high remission rates remain common, leading to the concept of treatment-resistant depression (TRD): a classification applied to patients who fail multiple courses of therapy. A patient with TRD can only be identified after repeated, and often prolonged, therapeutic efforts.

Anxiety-like and depression-like behavior in Maudsley reactive (MR) and non-reactive (NMRA) rats.

1. Female MR ("anxious") and MNRA ("non-anxious") Maudsley rats were tested in the CSD behavioral conflict paradigm (anxiety-like measure) and also in the FST paradigm (depression-like measure). 2.

An electrophysiological evaluation of serotonergic dorsal raphe neurons in Maudsley rats.

Extracellular electrophysiological recording techniques were used to study serotonergic dorsal raphe (DRN) neurons in Maudsley Reactive (MR), Maudsley Non-Reactive (MNRA) and Sprague Dawley (SD; reference control strain) rats. No significant differences were observed in the average discharge rates of DRN neurons from SD, MR AND MNRA rats. The sensitivity of DRN neuron somatodendritic 5-HT1A autoreceptors to the inhibitory effects of i.

Electrophysiological characteristics of locus coeruleus neurons in the Maudsley reactive (MR) and non-reactive (MNRA) rat strains.

Extracellular single-unit recording techniques were used to evaluate the physiological and pharmacological characteristics of noradrenergic locus coeruleus (LC) neurons in urethane-anesthetized Maudsley reactive (MR) and non-reactive (MNRA) rat strains, a presumed genetic model for differences in 'anxiety'. LC neurons from MNRA rats were found to have a significantly higher basal discharge rate than LC neurons from either the MR or Sprague-Dawley (SD) rats. The discharge pattern of MNRA LC neurons also differed significantly from that of LC neurons from SD and MR rats, with LC neurons from MNRA rats exhibiting a burst-like pattern of discharge.

Conflict behavior in Maudsley reactive and nonreactive rats: effects of noradrenergic neuronal destruction.

The present studies were designed to examine the effects of treatment with the noradrenergic neurotoxin N-(2-chloroethyl)-n-ethyl-2-bromobenzylamine HCl (DSP4; 65 mg/kg, IP) on conflict behavior in the Maudsley reactive (MR) and nonreactive (MNRA) rat strains. In daily 10-min sessions, water-restricted rats were trained to drink water from a tube that was occasionally electrified; electrification was signaled by the presence of a tone (7-s duration; ISI = 30 s). Consistent with previous reports, the number of shocks accepted by rats of the MR and MNRA strains did not differ initially, but MNRA rats exhibited a dramatic increase in punished responding relative to their MR counterparts over the course of several weeks of conflict testing.