I think they're superficially different, and continuing the eating disorder analogy, consider this anecdote. in the middle ages, monks and nuns used to torment themselves in many ways. While men used various inventive self-corporal-punishment techniques, women mostly employed one: starvation. It was their fight against their earthly body, which they tried to minimize as possible. So was that an eating disorder? Absolutely! It's just that today, instead of reducing your earthly body to become more spiritual, women (mostly) have other excuses for the same practice, namely modern standards of beauty. When a sociologist or anthropologist encounters something like that, the assumption is that a deep underlying human psychological need uses contemporary ideas and beliefs to find justification. When it was "known" that superhuman deities rule the world, the afterlife was their domain; now, when science rules, ideas from science fiction explain those (currently?) superhuman abilities and the after-life they bring. So the same deep cause is expressed using contemporary ideas.

If you don't like the word religion, we can call it "a belief in the afterlife", although the same trend applies to other behaviors that have commonly been considered religious, so the correlation is far stronger than just a belief in the afterlife (there are also notions about "purity" that are now explained by pseudo/shoddy science).