Answer:
Dr. Wasserman is demonstrating Confirmation bias.
Step-by-step explanation:
Confirmation bias can be described as a condition in which a person tends to interpret new information in favour of the prior beliefs that a person holds. In this scenario, Dr Wasserman already had beliefs that the new antidepressant would work. Based on these beliefs whenever a client came to him, he looked for patterns which would approve the fact that the antidepressant is working efficiently. Hence, Dr. Wasserman was performing confirmation bias.