What is this obsession called?

In a particular episode of The Big Bang Theory, Sheldon shows Amy how along the years he has hoarded every single thing he has ever encountered or used in life (basically from the past like books, games, PCs).

I believe this is OCD, but I wanted to know the particular name of the OCD. Searching online I have encountered, "Compulsive Hoarding," but it seems too generic given that it is from the point of view in hoarding everything not essential items from the past.

"Compulsive Hoarding" is more of hoarding everything and not essentials from the past.

If anyone could help me with this.

Solution 1:

According to Wikipedia, psychological research on this topic is relatively new, and both hoarding and compulsive hoarding are the official terms for now:

Compulsive hoarding, also known as hoarding disorder, is a behavioral pattern characterized by excessive acquisition of and an inability or unwillingness to discard large quantities of objects that cover the living areas of the home and cause significant distress or impairment.

(...)

Researchers have only recently begun to study hoarding, and it was first defined as a mental disorder in the 5th edition of the DSM in 2013. It was not clear whether compulsive hoarding is a separate, isolated disorder, or rather a symptom of another condition, such as OCD, but the current DSM lists hoarding disorder as both a mental disability and a possible symptom for OCD.