Final answer:
Lee's difficulty following conversations and memory issues when depressed are examples of cognitive symptoms of depression, which include concentration and memory problems.
Step-by-step explanation:
When Lee is depressed and has a hard time following conversations, forgetting much of what was talked about, this reflects a cognitive symptom of depression. Cognitive symptoms include difficulties such as trouble concentrating, slowed processing, and memory problems. Depression not only affects mood but also impairs cognitive functions like attention, memory, and the ability to process information efficiently.