Question

The figure below shows the effect of ketamine on a clinical depression score. Applying the indirect response model methodology, what type of effect might the drug be having: (stimulation or inhibition) of (production or loss)? Explain.

0.5 mg/kg ketamine IV MADRS 40 35 30 25 Placebo 20 Ketamine 15 10 -60 4 11 230 Day1 Day2 Day 3 Day7 Day 10 Day 14 Minutes ays Zarate et al (2012) Biol Psych

Answer 1

The figure given in the question describes about the relationship between ketamine and clinical depression score. The blue line represents the effect of placebo and the red line represents the effect of ketamine.

From the graph, we can find that the clinical depression score decreases significantly after ketamine injection. The score reaches the baseline after 10 days. So, it is clear that the drug (ketamine) decreases the clinical depression score and thereby had an inhibitory effect on depression.