Things here are broader than the physical. Not for all people who are depressed, but a general absence of desire is common. It includes desire for physical things that you may have once liked or collected. Lack of desire for social things like friends or lovers or perhaps any contact with other people. Even the desire to be alive, which for most people is just a given, can be absent. I, for example, was not actually suicidal, I just had no desire to exist, but also no desire to put forth the effort to end my existence.

I didn't interpret that in the sense of material items. If work and love are things then experiences in general are things.

In that abstract sense wanting things isn't materialistic. Even if you want to live in a cabin on Walden Pond, you still want a "thing".

I think this is meant in the context of having goals for oneself, some drive about something(s) to make you want to get out of bed ... not simply consuming products you don't need

seems like you've confused yourself with a literal interpretation

Desire is the root of human suffering. This is a widely held belief to put it mildly.