Affective biases shape cognitive and emotional behaviour and are important in major depressive disorder (MDD). Modulation of affective biases by the NMDA antagonist, ketamine, may underlie its antidepressant effects but not all NMDA antagonists are efficacious. Some studies suggest ketamine's efficacy involves non-NMDA mechanisms e.g. via its active metabolite HNK (2R, 6R)-hydroxynorketamine),...
Abstract Psilocybin, a serotonergic psychedelic, can produce rapid and enduring antidepressant effects in patients with major depressive disorder (MDD)[1, 2], yet the neural mechanisms underlying these effects remain unclear. Negative affective biases are an important neuropsychological mechanism central to the development and perpetuation of MDD[3]. Using a translational rodent model, we...
Abstract The serotonergic psychedelic, psilocybin, shows potential for rapid and sustained antidepressant effects but the underlying mechanisms remain unknown. Using a chronic interferon-alpha–induced rat model of depression, we show acute psilocybin (0.3 mg/kg) reverses impaired reward-induced biases within 24hrs, with effects enduring for at least 7 days. This suggests psilocybin can restore...
Abstract Background Behavioural studies in animal models represent a critical component of psychiatric drug development. Positive results in animal studies have identified novel therapeutic targets for major depressive disorder (MDD) but efficacy in humans has largely not been borne out in clinical trials. A possible reason for this failed translation is inappropriate dose selection and the...
How rapid-acting antidepressants (RAADs), such as ketamine, induce immediate and sustained improvements in mood in patients with major depressive disorder (MDD) is poorly understood. A core feature of MDD is the prevalence of cognitive processing biases associated with negative affective states, and the alleviation of negative affective biases may be an index of response to drug treatment....