Comparative effectiveness of cognitive and dynamic therapies for major depressive disorder in a community mental health setting: study protocol for a randomized non-inferiority trial.

BACKGROUND: There is substantial evidence that cognitive therapy is an effective intervention for the treatment of major depressive disorder. Although dynamic psychotherapies have been widely studied and are commonly practiced worldwide, there are few randomized comparisons of cognitive therapy and dynamic therapy for major depressive disorder. METHODS: We are completing data collection on a randomized non-inferiority trial comparing the effectiveness of cognitive therapy and short-term dynamic psychotherapy in the treatment of major depressive disorder in the community mental health setting. Therapists employed in the community setting have been recruited for training in either short-term dynamic psychotherapy or cognitive therapy. Patients seeking services at the community site who meet criteria for major depressive disorder based on a blind independent diagnostic interview are randomized to 16 sessions of treatment. All patients are assessed at baseline and months 1, 2, 4, and 5 utilizing a comprehensive battery. DISCUSSION: This study adds to the growing literature evaluating the effectiveness of short-term dynamic psychotherapy for specific diagnostic groups. These results will have implications for the dissemination of effective interventions for major depressive disorder in community mental health settings. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov, a service of the United States National Institute of Health. NIH Identifier: NCT01207271. Registered 21 September 2010.

Single unit activity in the lateral septum and central nucleus of the amygdala in the elevated plus-maze: a model of exposure therapy?

The central nucleus of the amygdala (CeA) is a major output region of the amygdala involved in organizing the expression of fear. There is also evidence that the lateral septum (LS) provides inhibitory control of neurons in CeA and is involved in the relief of fear. This study examined single unit activity in the lateral septum (LS) and the central nucleus of the amygdala (CeA) in the open and closed arms of the elevated plus-maze, a highly validated animal model of fear and anxiety. The general presumption is that animals normally avoid the open arms because the open arms are relatively more anxiety provoking than the closed arms which represent relative safety. It was expected that neurons in CeA would increase their activity in the open arms relative to the closed arms indicative of increased anxiety and that LS neurons would decrease their activity on the open arms. Contrary to expectations it was found that the preponderance of units in CeA decreased their firing rates on the open arms compared to the closed arms. An increase in firing rates in LS was seen in the open arms compared to the closed arms. The data suggest that when animals are placed on the open arms a compensatory process takes place to suppress fear so that the animal can engage in adaptive behavior. We liken this process to that which takes place in exposure therapy for phobias in humans which involves the inhibition of fear resulting from Pavlovian extinction.

Effects of chlordiazepoxide on single-unit activity in the septal region of the freely moving rat: aversive vs. non-aversive contexts.

Evidence suggests that stimuli that have the property of inhibiting fear in a Pavlovian fear conditioning paradigm increase cellular activity in the lateral septum, a result consistent with the idea that the lateral septum is actively involved in the inhibition of fear. The experiments reported here were designed to determine if an anxiolytic drug with fear-inhibiting properties would also increase neuronal activity in the lateral septum in a manner that might relate to its mechanism of action as an anxiolytic. An experiment was performed to compare the effects of the benzodiazepine anxiolytic chlordiazepoxide (CDP) upon single-unit activity in the septal region of the rat brain during Pavlovian aversive conditioning with the effects of CDP in a non-aversive context. During Pavlovian conditioning there was a decrease in unit activity in the more lateral regions of the septum, the dorsolateral and ventrolateral nuclei, when a stimulus signaling footshock (CS+) was presented. This conditioned suppression of unit activity was blocked by an intraperitoneal injection of CDP. Additionally, CDP increased baseline unit activity in these regions in the absence of conditioned stimuli. In the more medial regions of the septum, the intermediate lateral septum, we observed few consistent changes either to the conditioned stimuli or to the drug. In a non-aversive context CDP had either no effect at low to moderate doses, or a suppressant effect at a higher dose. The results support a fear-relief hypothesis of lateral septal functioning and suggest the lateral septum as a possible site for the anxiolytic action of benzodiazepines.