Initial effects on sleep
During the initial side effect phase of helminthic therapy, some self-treaters may experience insomnia or hypersomnia - especially if they have taken larger doses - while others report improved sleep.
Insomnia has been noted by an HDC user.
I took my second dose of HDC 8 days ago and have been suffering from insomnia. Nothing too bad just waking up 1.5 hours earlier than normal every day which is very unlike me. I took 30 the first time but this time took 50 just to see how I tolerated a higher dose. I have also had nasal congestion. 
And by several users of NA.
This is day six since my inoculation and for the past two days I've felt a little hyperactive and have had pretty bad insomnia. Although I am prone to these problems anyway, it's pretty unusual for it to happen a couple of days in a row like this… I notice one other poster mentioning a deterioration in sleep quality after about 10 days. 
For the past two weeks (after inoculating with 5 NA) I've barely slept. Some nights I'm getting as little as three hours and then I'm still awake the next night even though I feel tired. (Link expired)
I inoculated with 5 NA close to 3 weeks ago and I've suffered from insomnia for the last 5 days or so. This is highly abnormal for me as I usually fall asleep in less than 1 minute. Sometimes I fall asleep in less than 10 seconds according to friends. (I might have narcolepsy, haven't been tested) Now it takes me 3-4 hours to fall asleep every night and I still wake up 5-10 times after that. I haven't had insomnia in over 10 years.
I've never had an issue falling asleep or falling back asleep, but now (7 weeks after inoculating with NA) odds are much higher I'll have a tough time falling back asleep if I awake. Also, I'm a life long nap taker, and always for 15-20 min. However now I tend to wake up after 12 min or so - I almost never sleep to my alarm. And also I still tend to feel sleepy during the day. 
Initial insomnia typically resolves once the worms have become established.
First inoculation felt negatively affecting my sleep. But after some weeks or months, I recognized my sleep improved a lot, and today it's much better than before starting my 🪱 treatment. I wasn't expecting such a lovely side-effect... 
Occasionally, a degree of insomnia may persist.
I used to be able to sleep like a rock and nap too but it's a bit more variable now (at 14 months post inoculation with NA). Sometimes awake long periods in the night, sometimes sleep well. Napping is hit and miss. 
A few self-treaters have experienced hypersomnia.
I took my 6th dose of HDC. Now, I am in my 11th week of taking those. The only side effect that I have really felt consistently throughout the entire journey thus far is sleepiness. I would not call it fatigue because I am not exhausted at all. There are moments when I just have to fall asleep. This is a huge shift from my sleep deprived past. I would never sleep more than 4-5 hours per day in the past 10-12 years. Now, it is like ‘hey, I know you just slept 10 hours last night, but how about a 2 hour nap? 
5 days post inoculation (with 35 NA) and I have excessive sleep. I sleep my usual 9 hours, get up for 2 or 3 hours of feeling woozy and then get so tired that I can't stay awake. I sleep another 5 hours. Then I get up for 7 hours and feel pretty good. At the end of that I get tired so quickly and intensely that the first night I fell asleep at a friends place mid-conversation, and last night on my computer keyboard at my desk. Being properly awake for only about 7h/day is a bit of an issue, but I am getting good deep sleep that I am hard to awake from, so I don't think it is a matter of sleep quality. 
I've also noticed the excessive sleep issue post inoculation. I'm normally good on 7-8 hours of sleep, but now I wake up tired after 10+ hours of sleep, and I get super tired towards the end of my work day.
Early sleep improvement
Improvement in sleep may begin early.
I’ve used sleeping pills every night for the past 30 years and after my second dose of HDC haven’t needed them!😳 An unexpected bonus as I’m on helminths for Sjögren’s syndrome and RLS. 
My (NA) bounce effects: … increased quality of sleep - had first dream I could remember the details of for longer that I can recall. 
I’m 3 weeks post 25 NA inoculation and last night I actually got sleepy at 10pm, I haven’t felt like that since I was a kid. I felt sleepy and gradually just fell asleep, like a normal person. It was amazing... If this is a permanent effect of NA I will stay on them forever, even if they don’t affect any of my other symptoms! (Link expired)
The most noticeable effect of my first dose of TSO was a big improvement in sleep. I think my insomnia tends to be bipolar/inflammation related. (Edited from two posts:  
NA is great for insomnia in my opinion/experience. (Reported at almost 11 weeks after the first inoculation.) 
I sleep like a rock most nights now. I wouldn't say I had a sleep disorder prior to this, I slept okay. However, It has been noticeable how much better sleep is now. 
Long term sleep improvement
The quality of sleep is frequently improved in the long term, with a reduction in insomnia.
I've lost that 'tired but wired' feeling that stopped me relaxing properly, and I've started to sleep better.
After 9 months and 45 HWs later I have stopped with all sleeping medications… I am waking up with more energy, going to sleep naturally, and not crashing during the day. I credit the HWs with this improvement after suffering for more than 6 years and trying many different treatments with no improvement.
Yesterday she went to sleep before the rest of us. This has practically never happened.
Two months ago I could not sleep without a dose of salbutamol, and that only for three hours of sleep. It was hell. I thus spent the last two years. I was so worried and so resorted to HT. Now I wake up with the alarm again!
Sleep quality improved beyond recognition. 
My Circadian rhythms have normalised and I am getting 8 hours of solid sleep every night. 
Before I needed a good 8 hours and more - now about 6 and a half to seven is plenty.
His sleep is much better; his hypopnea is significantly reduced. The amount of naps he takes have been cut way back. He doesn't have to sleep fourteen hours on the weekends now. He sleeps better at night because he is much less congested. 
The biggest improvement I have found (5 months into using NA for ankylosing spondylitis) is in my sleep habits. I take one celecoxib 200mg tablet to sleep at nights where, even with the medication, I still struggled to get a full nights sleep, often waking up at 4.30am. Now I can last the night without discomfort.” 
I’ve had a slow yet sure resolution of insomnia symptoms, and nightmares, over the last 2.5 years, using NA for the whole time, and adding small doses of TSO during the past year. I went from requiring a sleep aid cocktail of 2-6 different medications - that sometimes did not work - to currently only requiring one (anxiety) medication and a melatonin supplement. I’m now adding 8 NA every 7 weeks and doing really well. (Via private message)
While using NA for the past 3 months, I've had great sleep. No more nightmares and no more night terrors. I believe I used to have mild sleep apnea before. Perhaps the nightmares and sleep terror were connected to that. While on NA, I don't notice sleep apnea anymore, and my husband has confirmed I snore less in weeks 1-3, and not at all from 7-12 weeks. 
I had had insomnia for decades, but TSO made a dramatic and speedy change, I think it was just before or after my 3rd dose. It has been over a year since I started TSO and the effect mostly persisted even when I had no helminths for several months. (I also think my current NA is doing the same thing.) I started HT for RA, and never thought about the insomnia being improved until it happened. 
When I started TSO, my sleep really changed. I started from extreme long term insomnia, so that's one thing. Then the insomnia disappeared but it came back and I had a period of very short sleep cycles. Then it turned into sleeping only 6 hours or so. Because of my history I judged that as inadequate (I was used to sleeping 9 or more hours IF I slept at all, and "they" say we need 7-8.) And actually what happened is that I figured out that the new normal was healthy. I had lots of energy, felt good, etc. Now I find if I sleep too long I have more pain. I find that naps are sometimes appropriate but not often needed, etc. I need to respond to my sleep, there are no particular rules. For me, finding my best sleep cycle(s), and discarding preconceived ideas, was an integral part of my TSO experience. 
I have insomnia caused by narcolepsy, disautonomia and mast cell reactions, and the worms help the insomnia. (Edited from two posts:  
I had insomnia as a symptom of ME/CFS. I've been taking NA in very small doses, 3 NA every 3 months, and my insomnia has almost vanished. It took nearly a year but I do attribute the improvement to NA. 
Dreaming in colour for the first time!
I am currently having mostly fun vivid dreams, sometimes even in color. (I only ever had black and white dreams!) 
On NA, I don't notice sleep apnea anymore. 
I think also apnea is improving for me. Haven't used my machine for a few weeks. I suppose I'll do another sleep study some day to confirm, but I'll probably wait a couple years because it's a hassle and to let the full effects of the worms show up. But I'm only on NA right now and I didn't notice either way with TSO. 
My husband confirmed I snore less (while hosting NA), and weeks 1-3 and 7-12 not at all. 🤩 
One self-treater has reported the disappearance of previously regular night terrors.
I just realized since inoculating with NA five weeks ago I haven't had a single night terror, something I would experience a couple of times per week prior to this treatment.