I have racing thoughts often. Usually I have a thought stream that is going so fast from, first, creation to, lastly forgetfulness (thought just fades), so fast that I cannot communicate what my mind is spewing out because, for lack of a better description, I cannot "grasp" or "catch" a part, or parts, of the thought stream before it's already passed out of my awareness and memory. You can imagine how frustrating this can be!!
If someone were to interrupt me while this is going on and ask me what I was thinking about, which happens, I can't recall what my mind was so engrossed in--very frustrating--and I tell them that I simply don't remember.
These racing thoughts make it impossible for me to utilize all of my conscious mind to think, speculate, and communicate at full, normal capacity; in effect, I literally appear less intelligent, and I know I come off as spacey. Also, I have noticed that when this is happening, my pupils tend to be fairly dilated.
Another type of racing thoughts (that I think also qualifies) is a state where my thoughts are so fast that it feels like I'm not thinking at all; it's as if my brain is "locked" into a "stream of consciousness" type state where so much activity is going on that I exhibit a short of blank stare.
I have been checked out by a neurologist since this started happening in my early 20s. The neurologist found that, during the entire EEG test (measures brain activity), my brain showed signs of seizures, especially seizures that would be both "simple partial" and "complex" seizures, rather than the "tonic clonic" (a.k.a. grand mal) seizures.
He put me on a drug called Depakote ER as the primary anti-convulsant (I now take 1500mg at night), and he also put me on Keppra XR 1000mg at night, and 1000mg at bedtime.
The change was incredible; I stopped losing track of time (apparently a sign of partial and complex seizures). I had NORMAL control of my thought stream--it was slow enough now for me to be able to "work with it" so to speak--I could communicate what I was thinking to the full extent of my thoughts, and they didn't fade from my memory nearly as quickly. Overall it's been like getting half of my mind back, or at least unlocking a major part of it.
I also sleep much better and a normal 8 - 10 hours instead of the usual 4 - 6 hours I could only get before treatment.
I also found out from the neurologist that, what I thought had been normal for vision my entire left since it had always been this way, seeing vibrant "clouds" of colors blending into each other and swallowing each other at night was not normal. Neither, it turns out, was the extent to which I saw, for lack of a better word, "auras," around people especially when lost in thought and in racing thoughts.
So, basically, the Depakote ER and Keppra XR helped me to be able to live my life to the fullest. If it hadn't been for a car accident that led to the EEG test, I would probably still be having these racing thoughts and inadequate sleep--only half a night's worth and with frequent waking.
I would recommend seeing a neurologist, not just a psychiatrist, if you have this problem. An EEG can really troubleshoot things gone awry in the brain!
Hope this helps
-Francisco