I believe the infant needs to undergo some sleep training. From personal experience, this is not at all fun for the parents. It requires absolute dedication from the parents in order to be effective, and in the beginning there may not seem to be any benefit to the parents.
There are various methods taught, such as the "cry it out" Ferber method. I'm not well-read on any of them, but I have heard several times that letting a child cry it out can cause mental or emotional harm. With that in mind, these are the techniques my wife and I used to transition my son from co-sleeping to sleeping in his own crib at night:
- Have a calming routine before bedtime, such as a bath followed by reading. This should be done at the same time every night.
- Take the child to bed at the same time every night.
- Have both parents tell the child goodnight.
- Have one parent stay in the room until the child falls asleep. The only things the parent is allowed to do are:
- Tell the child, "No" when they sit/stand up in their bed/crib. This is the only time you should be saying, "No". You don't say, "No" to questions or cries.
- Hug the child once per sitting/standing, but the hug must not lift the child. It has to be managed with the child sitting/standing in the crib. It's not always comfortable for the adult to do. I believe this is a healthy compromise between "Cry it out" and attachment methods, not only for the child but for us as parents.
- Gently place the child back down to a laying position, without lifting them up.
- Tell the child, "Lay down" as they're laying the child back down.
- No exceptions! No other talking!
- The tone of "No" and "Lay down" should be calm, but firm and assertive. They should not sound impatient, angry, or exasperated. If you've ever watched The Dog Whisperer with Cesar Millan, his approach to commanding dogs also works well for young children.
- Once the child seems to be asleep, the parent on duty that night should wait several minutes before leaving the room.
- If the child wakes up again after that, the same on-duty parent goes back to the room and start back at step 4. This may happen many times in the night at first.
- Wake the child up at the same time every morning. If feasibly, this should be done by the off-duty parent from the night before, because they're more likely to have gotten enough rest to wake up early.
- Do not allow extra napping during the day. One hour-long nap midday may be sufficient. Nap times vary by child. The hardest part about daytime naps is making sure the at-home parent's own naps aren't allowing the child to nap too long. Set an alarm if you're about to doze off after the little one does!
These are the additional rules we set for ourselves:
- On the first night or two, both parents should be be present for the entire time it takes for the child to fall asleep the first time. They can alternate between who is going through the step 4 sequence. However, the parents can not talk to each other. Doing this together the first time lets the child know that it's how things work now.
- If the child is calling incessantly for the other parent, and that parent is still awake, then that parent may come in once per night to go through the step 4 sequence: Say, "No", give a hug/pat, lay the child down while saying "Lay down." It's important that this is done no more than per night by the off-duty parent, and it should be done while the on-duty parent is still in the room. It tells the child, "Mama isn't going to rescue you tonight. She's on my side."
- Don't focus on watching the child. You'll be able tell when the child sits/stands without staring directly at them. Focus on something else in the room, or even the back of your eyelids. This tells the child that you're a reassuring presence, but you are not a source of attention or interaction. A few times I even listened to music with earbuds (but you have to make sure you device screen stays off while you're in the room. Best kept in a pocket).
These tricks helped us keep our sanity:
- Bring in a comfortable chair to sit in.
- Be prepared for a long battle in the beginning. (I think our first night's screaming/standing/crying phase took at least 2 hours before he fell asleep the first time. It was much shorter the second time that night, but the second night's first cycle was nearly as long as the first night's.)
- Be prepared to lay the child down possibly hundreds of times in the first cycle. You need to do it literally every time the child sits/stands. Some might get the message after a few dozen attempts. My son is very willful, and I stopped counting after 100+ times the first night.
- Be prepared for this to take at least one exhausting week's worth of dedication by the parents.
- Be prepared to have to go back into the room after these most likely scenarios: 1) You just stepped out the door 2) You just lay down in your own bed 3) You just fell asleep
- Before bed, assess your child's health so that you know your child isn't in any sort of distress from illness or gastrointestinal discomfort, this is important because:
- The child may use every type of cry and scream in their arsenal. Our son went through his usual cries: I'm unhappy, I'm tired, I'm angry, I'm hungry, I don't feel well. Then, when those failed, he invented new ones: I'm being murdered, I'm dying, I am become death destroyer of worlds. These cries will illicit strong emotions from the parents. You'll want to cave in, because it sounds like your baby is in pain and really needs you. That's the point of such outbursts: to get the parent to cave. And if you give in to those screams, you'll only find that you've taught the child to escalate even further to get their way.
- It's okay to skip saying, "No" or "Lay down", and even the hug/pat sometimes. It doesn't have to be robotic. Sometimes you'll be too exhausted or frustrated to talk without having a tone that's not calm, and that's okay. The main thing is that you have to lay the child back down every time, whether or not you speak. In fact, as the night progresses you should offer the feedback less and less often anyway, until you're only laying the child back down. A
- Sometimes, the physical and emotional toll this routine takes on the on-duty parent can be too much for the night. In that case, it's okay (and possibly necessary) to tag in the off-duty parent for a while. It doesn't have to be for the whole night. Sometimes my wife and I just needed to trade each other for 15 minutes.
- Keep perspective. Being dedicated to the routine, from start to finish, is very difficult in the beginning, but in the end it means the entire family can get more restful sleep. Also, it helps to be in a mindset of sympathy for your child, rather than a mindset of the child being antagonistic. Yes, the child is intentionally aggravating you in order to get their way, but they're doing it because they are so attached to you and are used to things being done differently. They trust you to take care of them, so you need to show them that this new way is okay, and that the baby will be okay.
- You have to be a team. If both parents are in the home at night, then they need to take turns being on-duty, and they need to both follow the routine. If one parent is more verbose, or picks up the child at certain times, then the difference in how the parents react is going to prolong the situation.
Our son was about 1 when we did the sleep training. It may have been 14 months, I don't recall exactly. I think it took at least a full week until things settled down for us. Our situation was similar, except we usually didn't let the "cry it out" stage last more than a couple minutes. It was easier to let our son come into our room. Things had to change when I wasn't getting enough sleep for school and work.
I was exhausted that entire week, but it paid off. Eventually, our son stopped fighting bed time as much and stopped waking up and crying so much through the night. (Of course, once we changed from crib to bed we've encountered different bedtime issues!)
I don't have sources right now to tell you about how I came about this method. At the time I read a lot of material on sleep training and developed this strategy based on all the insights I agreed with. I feel I struck a balance between "Cry it out" and "No tears".
I would like to add that I agree with deworde's answer, in that a failure to commit to the plan doesn't mean the parents have failed. It's likely that instead, the plan has failed. As you can read, I put quite a bit of effort developing and enacting my customized plan, because I knew I couldn't commit to some of the existing "book" methods.
If the parents find a different plan, or make their own, these are the most important aspects the plan needs to have:
Routine - The child needs to expect the same thing every night and morning. This serves both psychological and biological purposes.
Consistency - How each parent reacts to different situations needs to be consistent, and it needs to be consistent between them.
Commitment - The parents need to be able to physically and emotionally commit do the sleep training plan for a reasonable amount of time. Some lucky parents only need a day, others more than a week.