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The Toddler (16-18-ish) Month Regression: What is it and what can be done about it?

The Toddler (16-18-ish) Month Regression

When it comes to sleep, the graduation from “baby” sleep to “toddler” sleep usually happens around 18 months. This transition involves a subtle biological change associated with the transition to one nap, but the sleep regression that many toddlers experience is caused by an explosion of cognitive and emotional development. We call this the 18-ish month sleep regression because it can happen anywhere between 15-24 months. For most toddlers, it hits right around the 18-month mark. Your toddler might have a true regression and get better with minimal effort after a rough week or two or he might get stuck in a bad pattern that will only get better with intervention. The key to getting back on track quickly depends on how you interact with your child during what can be a tricky time.


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The Science Behind the 16-18 Month Regression

Right around the 18-month mark toddlers go through an explosion in development. The transition to one nap has usually happened by this time (see our nap blogs) and making it through the day on just one nap can be a tough transition. In addition, recent research has shown that the biological bedtime conferred by the circadian rhythm drifts by as much as an hour later during toddlerhood. (In other words, that same tried and true baby bedtime you’ve had for months stops working!). This circadian rhythm shift is problematic because the strongest drive to be awake happens right before the biological bedtime. The practical consequence of this is that you can end up with a toddler, who is obviously tired from having just one nap, but who cannot sleep at bedtime.

It gets worse. Now, biologically you have a tired child who cannot sleep, so what’s an overtired toddler to do with all that extra time? Unfortunately, this age is also when testing behavior happens and it’s also a time when a second separation anxiety can hit with a fury (see our blog on the first separation anxiety regression at 9 months. Some children will fill their extra awake time with experimentation that many parents interpret as active manipulation, but it’s really more just figuring out limits and consequences – What happens if I yell? Can I get out of this crib? Jumping is fun! How long can I jump? What happens when I sign/ask for milk? What happens when I sign/ask for a snack? What happens when I sign/ask for the stroller? Is it nice to sleep on the floor? Can I sleep in my parents’ bed?

On the other hand, with moderate to severe separation anxiety, some children develop genuine but sometimes irrational, fears – Where is my mom going? What if she doesn’t come back? What if I need her and she doesn’t come? What is that shadow? A dog barked at me today and it was scary. What if a dog comes in my room?

Since natural wakings happen throughout the night at the end of every sleep cycle, these problems can repeat themselves for hours in the middle of the night. This can be even more challenging for children who have not yet developed strong language skills (most haven’t at this age) because it’s hard to know whether cries should be interpreted as “I want that toy” or “I’m worried”.

Some children can experience elements of both of these issues, making it even more difficult to figure out how to respond appropriately.

What do I do about this regression?

Avoid making big sleep changes during this time.

Sometimes you can’t avoid life changes, like moving or the arrival of a sibling, but if your child has sleep issues or if you want to make a change in your child’s sleep experience, then it’s best to try to make those changes before the 18-month mark or wait until this volatile period is over (e.g. sleep location transitions, pacifier weaning etc). We know that sometimes you just can’t wait, but for those situations we recommend considering booking a consultation with us so that we can evaluate your child’s individual needs.

Provide your child with consistency and clear limits.

If your bedtime routine changes every day or doesn’t have a defined end, then it will be tough to convince your child that there is a reason to stop reading books, singing songs, or otherwise engaging with you. Intermittent “giving in” is actually very reinforcing (think gambling), so negotiating with your child (e.g. if I read you one more book, then you have to promise to go to bed) can actually backfire in the long run. It can be really helpful to use a bedtime checklist with pictures or to glue pictures of the steps in your routine on cards that your child can put in an envelope when each step is complete. Once the end of the routine happens, you should not give in with more books, snacks or activities. The end should be the end. This doesn’t mean that your routine cannot involve you being in the room with your child, but even if you stay in the room, you can and should expect that your child follows the “sleep rules” at the end of the routine.

Respect your child’s need to participate.

At this transition toddlers generally want to play an active role in their experiences. Although you should maintain a consistent bedtime routine, you should incorporate “jobs” and limited choices for your child to actively participate in the process. For example, you can offer two pairs of pajamas and let your child choose one, you can ask your child to get his toothbrush out of the cabinet or move the stool to the sink, or you can have your child find his lovey and put it in his crib. All of these things give your child some of the control that he’s craving, while still allowing you to maintain predictability and limits. Because, let’s face it, limits are actually reassuring to your child who wants to know you are able to handle any situation – including bedtime!

Determine your child’s biological bedtime.

Make sure you are asking your child to sleep when he’s ready to sleep. Remember, the biological bedtime can drift as much as an hour later during toddlerhood. If your child is not ready for sleep, then sleep training will not work no matter what strategy you use. Don’t put your child down until it’s clear that he’s able to sleep. The best way to figure out your child’s bedtime is to take his average fall asleep time from the last week and put him down at that time. This might be a socially crazy time, like 10:00 PM, but if that’s when your child normally falls asleep, it’s the right place to start. Once your child is falling asleep quickly after your routine, you can gradually move bedtime earlier by 20 minutes a day. Once you reach the time that works for your family stick to it and try not to vary bedtime by more than 30 minutes from night-to-night.

If your child is a tester….

It is extremely important that your routine has a defined end and that you reinforce that after the routine is over, it’s over. You should change your behavior after the bedtime routine. During the routine, you engage, you snuggle, you make sure all of your child’s needs are met. After the routine ends, you should transition to night-mode: stick to a good-night mantra, or express soothing murmurs or just soft “shhhh”ing, with no more conversation, toys, games, or conversation.

If your child is in a crib (which we strongly recommend), then you can frequently check in while repeating a mantra such as “good night, I love you, it is time to sleep.” Don’t engage or start a conversation. Repeat the phrase when you go in or in response to requests. For example, if your child asks for a banana, don't say "no, you already had dinner," instead, say "good night, I love you, it's time to sleep." Do the same thing in the middle of the night if your child wakes and makes requests.

If your child is in a bed (we don’t recommend making this transition before age three), then you may have to sit in the room and put your child back in bed over and over if he gets out. Or, you may have to leave the room and walk your child back to bed over and over. Every time he gets out, take his hand and put him back in bed while repeating your good night phrase. You should not provide any positive reinforcement if your child gets out of bed -- even a little tuck in or blanket rearrangement can lead to your child continuing to need you night after night. Repeat the same thing you did at bedtime in the middle of the night if your child gets out of bed. It is normal for this to be very hard and it's normal for it to take hours on the first few nights, because toddlers have an incredible capacity to stay awake.

If you opt to be in the room as your child falls asleep, then you will need to transition into leaving the room at some point -- that can be after a few nights of sitting with your child or it can be after a few weeks. Your timeline to transition out of the room really depends on whether the way you are managing your child's sleep is sustainable for you.

As always, safety is the most important factor in your nighttime parenting. Keep stuffed animals, pillows and blankets to a minimum in your child's crib (ask your pediatrician what is appropriate for your situation). If your child is climbing out of the crib, then that can add another complicated wrinkle. For more information on toddlers and crib climbing, read our article on how to keep your climbing toddler in the crib.

If your child is anxious….

Figure out what is causing the anxiety.

At this age it is totally normal for a toddler to become concerned that you might not be available when you leave or in the middle of the night. From an adult perspective we know that this is an irrational fear, but from your child’s perspective it is very real. Your child is learning how to regulate emotion and identify which situations deserve an anxiety response and which don’t. When trying to figure this out, don’t project your emotions on your child or ask leading questions like “Are you scared of the dark?” or “Did you have a bad dream?” or start checking under beds. That’s the fastest way to give your child new anxieties!

If your child seems to have typical developmental separation anxiety, then you will want to make sure that your child gets to see you at least once during nighttime interactions in order to alleviate that anxiety. Some research suggests that "camping out" in your child's room during these sensitive phases is the best way to get back on track during episodes of anxiety.

What is "camping out?"

Sit in the room without engaging, while intermittently repeating a good night phrase such as “you are safe, I love you, it is time to sleep.” Don’t engage or start a conversation. Repeat the phrase when your child asks for something like a tuck in, cuddles, or milk. Do the same thing in the middle of the night if your child wakes and makes requests. Toddlers are able to stay awake for a long time (sometimes a few hours), so it is normal for your child to take an extended time to fall asleep both at bedtime and for night waking during the first two or three days. Camping out is definitely helpful in alleviating anxiety, but it is still very hard and your child may get very upset even with you in the room. Remember, if you are in the room, then your child knows that you are available, if your child cries while you are in the room it is likely because you are not doing what he would prefer, which is a different kind of frustration than anxiety-induced cries.

If you opt to camp out in the room as your child falls asleep, then you will need to transition into leaving the room at some point -- that can be after a few nights of sitting with your child or it can be after a few weeks. Your timeline to transition out of the room really depends on whether the way you are managing your child's sleep is sustainable for you.

Camping out is not for everyone. If you don't feel comfortable doing something like camping out, then that's ok! There are other approaches, but they tend to be family and situation specific. For example, if your child wants to come into bed with you or wants to be rocked or nursed to sleep (yes, many toddlers nurse to sleep and if that works for you that's fine, if it feels like a sleep crutch, then read on!), then you may want to take a more phased approach to problem solving by making small changes, like first reestablishing the crib as the place to sleep or having the non-nursing parent take over night wakings. If you feel that you fall into this category, then consider booking an individual consultation with us, so that we can help you build a plan.

What if my child has anxiety for other reasons?

For some toddlers an event can trigger anxiety. We’ve worked with children who have had bee stings, car accidents, reactions to fire alarms, and major illness. Even more mundane stimuli, like a dog barking unexpectedly or a thunder storm can trigger night anxiety. If an identifiable stimulus is the source of your child’s stress, then you will need to be supportive and reassuring during the night until the stress from the event passes. This may mean sleeping in your child’s room for a time or staying with your child and actively soothing him until he is asleep. If your child’s anxiety seems to be more than just minor and passing, please see your child’s doctor for further evaluation.

What if my child has anxiety and is also testing?

It’s also important to note that sometimes toddler sleep problems can start as anxiety, but can evolve into testing. Imagine a scenario where your child has a bad dream and wakes terrified in the middle of the night. Obviously, you would respond with comfort and support to help him get through that tough night, BUT there is a good chance that your child might like the extra comfort that you offer and then in the future, he might wake up and call for you and use the words “bad dream,” because a bad dream led to a really nice outcome before. You can usually tell if this is happening, because the tone of your child’s waking will typically be different even when the language is the same. In this case you may start by being very supportive and responsive to the stress, but if the problem evolves, then you should evolve your parenting strategy with it.

Final thoughts

If you catch this sleep regression right away and if you have your child’s biological bedtime correct, then it should only be a few nights of drama before your child is back on track.

References (peer-reviewed literature)

  • LeBourgeois, M.K., Carskadon, M.A., Akacem, L.D., Simpkin, C.T., Wright Jr, K.P., Achermann, P. and Jenni, O.G., 2013. Circadian phase and its relationship to nighttime sleep in toddlers. Journal of biological rhythms, 28(5), pp.322-331.

  • Kahn, M., Juda-Hanael, M., Livne-Karp, E., Tikotzky, L., Anders, T.F. and Sadeh, A., 2019. Behavioral interventions for pediatric insomnia: One treatment may not fit all. Sleep.

  • Jacobson, J.L. and Wille, D.E., 1984. Influence of attachment and separation experience on separation distress at 18 months. Developmental Psychology, 20(3), p.477.

  • Guthrie, A., 1997. Separation anxiety: an overview. Pediatric dentistry, 19, pp.486-490.

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