Quite new around here. I've posted in a couple of Jeyl's "Episode Of The Week" threads, which I really like. This topic could have been more generalised, but I think it applies best to TNG - you'll see why in a moment. I hope this post isn't too long - I do go into a lot of detail, but that's because I'm hoping this will spark a detailed level of debate and interest.
In my opinion, the horror aspect of Star Trek in general is somewhat underrated. The elements of horror which appear in science fiction are probably underrated because they are both more fantastical and more subtle.
Now I'm going to make a very bold statement: In my opinion, Night Terrors has some of the most creepy and psychologically disturbing moments in not only all of television history, but perhaps film history, too. Why? Because the episode is overt enough that we know it's meant to be spooky, but too subtle for us to laugh at it. Case in point: the morgue scene.
The morgue scene is one of the most subtle freak-out moments ever, because it doesn't go for the obvious route of scaring the pants off the audience with cheap thrills; it's far more insidious than that. It's so simple: our doctor is left alone in a room full of dead bodies, which is quite normal for her considering her line of work. However, because she is hallucinating, the bodies appear to...all sit up simultaneously. She turns away, and they are lying down again. End of scene. That is all...nothing else happens. So why is it so scary?
It's highly fascinating to me that this one scene, in which not a drop of blood is spilled, no one is hurt and no one screams, is nevertheless more psychologically creepy, freaky and unnatural, IMHO, than any number of gory scenes in horror films.
That the corpses don't do anything other than make that ever so creepy rustling sound, and then sit up, could actually be the reason why it's so frightening: if they started moaning and lumbering about like zombies, even if they seemed to pose some threat to Doctor Crusher, we could still laugh at the scene and so it would lose its power. Because they do nothing other than sit up all at once in that horribly unnatural jerking movement, it's too subtle to be cheesy - we can't laugh at it, because it's genuinely freaky as opposed to silly. I find this very interesting...any thoughts? It might just be me, it might be linked to the fact that I first saw it when I was about five years old. I'm not sure. Either way, it's intriguing.
Moving on to other episodes, the general point I'm trying to make here is that the understated nature of the horror elements in TNG's particular brand of sci-fi is, perhaps, what makes gives them especially disturbing, get under-your-skin kind of creepiness, one which is too low-key to be sniggered at. Frame Of Mind is scary only because we see everything from Riker's point of view, and it's disjointed, weird and terrifying to him - and thus to the audience. Again, it's psychologically very powerful. Schisms is considered by some fans to be the scariest Star Trek episode ever, period, throughout all the episodes of every Star Trek series, and it's simply an alien abduction plot. Is Schisms more frightening than a gory horror film? It might not seem that way from the outset, but its level of spookiness is virtually unmatched...even though all the visual elements are, again, fairly subtle.
In the end, it has to come down to psychological horror, which lends itself really well to subtlety. Is psychological horror always going to be more frightening and disturbing to the human mind because it taps into our deepest fears, as opposed to simply aiming to shock? Some kind of demonic, gory, revolting film ought to be scarier, and certainly more depressing, but it doesn't seem to be, even when it's not something you can easily laugh at...maybe it's simply too extreme, and so it becomes corny. Does this mean that the visceral elements of horror are nothing without, or when compared to, the psychological ones? I can't think of any other reason why certain TNG episodes are still creepier to me than any number of films.
Hope that this all makes for some interesting food for thought and debate.