The idea in psychiatry is that speech is an outward manifestation of our thoughts, so basically all of the classic examples of thought disorder are of disordered speech. Psychiatrists can't know what we're thinking unless we tell them, so speech is what they go on. As in, if you're clanging in your speech, you are likely to be clanging with your thoughts too. However, I would tend to agree that mild thought disorder isn't necessarily obvious from speech to lay people, or if only interacting for short periods. You specifically mentioned clanging and neologisms though, which are pretty obvious examples that even lay people tend to notice, which is why I replied before as I did.

The issue with mild thought/speech disorganisation is that it can be perfectly normal and non-specific. Everybody makes up words on occasion, that's how we get new words in language, but that doesn't mean that they have thought disorder. Everybody loses their train of thought at one time or another, but that doesn't make it thought blocking. Everybody on occasion jumps from idea to idea, especially when excited, but that doesn't mean they are experiencing loose associations.

So I'm not sure that it's necessarily helpful to list everything that could possibly be considered mild thought disorganisation as people may worry that they have it when they're entirely within the normal range. Instead, I will ask, what is it that makes you think that you have disordered thinking? But, ultimately, I think that, if you are that concerned, you should consult a psychiatrist about it because they will be trained to spot it way better than either you or strangers on the internet. That way, you will know for sure.

All the best,

*Willow*