PROVIDENCE, R.I. [Brown University] — Motherhood’s many joys come with many sacrifices, including a heightened risk of mood disorders both during and after pregnancy. Among the causes and consequences may be the profound disruption of sleep that many women experience throughout the perinatal period.

Sleep specialist Dr. Katherine Sharkey, assistant professor of medicine and of psychiatry and human behavior, is working with colleagues to study perinatal anxiety and depression and to test a new intervention to help pregnant and postpartum women improve their sleep. The trial is still ongoing, but she’s finding that despite the conventional wisdom that expectant and new mothers can kiss restful sleep goodbye, it is possible to improve sleep by respecting the natural circadian rhythms that encourage us to sleep at night and remain wakeful during the day. Sharkey says the classic advice to catch up with daytime catnaps — that is, “sleep when the baby sleeps” — may be counterproductive compared to going to sleep consistently when night calls.

In advance of Mother’s Day, Sharkey talked about how more sleep — and perhaps better mental health — may be possible and beneficial, even when many new moms are counseled to just accept poor sleep and moodiness.

Why does depression and anxiety risk rise around pregnancy and the postpartum period?

Depression cases in women tend to develop at inflection points that are associated with hormonal changes and a change in lifestyle. If we look across the lifespan — times like puberty, pregnancy, postpartum, menopause — these are all times when we know there are blips in the development of depression in women. During pregnancy, expectant mothers have massive changes in hormones like estrogen, progesterone and beta HCG that are known to affect the brain. Then there is a dramatic withdrawal of those hormones after pregnancy. It’s kind of a neurochemical roller coaster ride.

At the same time women are experiencing profound role changes when they become mothers. There is a huge increase in responsibility and changes in their relationships, and revisitation of their own childhoods. It’s premature for us to say that we know the exact mechanisms for these increased risks, but it’s likely a combination of the biological changes and the social and emotional changes.

What’s the standard of care for women with perinatal anxiety or depression?

Psychotherapy and medications have been shown to be effective in treating depression and anxiety both during pregnancy and postpartum.

One of the biggest problems is a failure of health care providers to recognize the depression or anxiety of these women and/or reluctance to treat it, especially with medications, because of a concern about the safety of medications for fetal development and in nursing infants. But there are medications that have been shown to be safe and effective in pregnant and lactating mothers, and often the benefits strongly outweigh any potential risks. In addition, there are non-pharmacologic options including some that target sleep and circadian rhythms that we are investigating. There are also things like interpersonal psychotherapy and group psychotherapy —even some exercise and yoga work that’s been done.

Another obstacle is that women are often reluctant to seek care either because they feel stigmatized that they are depressed or anxious at a time when society expects them to be happy or just because they just aren’t aware of the safe and effective treatment options. We have also had women in our research studies tell us that they are afraid authorities will try to take their baby away if they admit to symptoms of postpartum depression.

We’re lucky in Rhode Island in that we have clear services available to pregnant and postpartum women who are experiencing depression or anxiety, including my research partners at Women’s Medicine Collaborative — specifically Dr. Teri Pearlstein, Dr. Carmen Monzon and Dr. Ellen Flynn. And the Women & Infants Hospital day program is another great resource.

What role do you think sleep plays in either causing or exacerbating perinatal depression and anxiety?

In pregnancy and the postpartum period, sleep disturbance is assumed to be a foregone conclusion. When women go to their doctors and say they have a sleep issue, they are waved off with an, “Oh, this is an expected part of pregnancy.” Even worse, they are told, “Oh yeah, just wait — it’s going to get worse when the baby comes.” There are no guidelines for how bad their sleep has to get before we offer them treatment. Women are also expected to be more moody or emotional during pregnancy. It can be insidious. People are told, “Oh, you are going to cry at the Pampers commercial,” so they may not recognize when their symptoms cross over from feeling a little more emotional to a mood disorder that could and should be treated. Not only does treating anxiety and depression during the perinatal period reduce women’s suffering, but it also improves outcomes for their infants.

The mechanisms by which sleep and circadian rhythms play a role in depression are probably both bidirectional and multifactorial. By bidirectional, I mean being depressed or anxious, having those emotions, we know affects sleep. But there are also now several lines of evidence showing that a sleep problem can precede development of depression and anxiety. And the mechanisms of that are probably multifactorial: everything from biochemical to cognitive.

"I think it is possible for sleep to improve, even during the perinatal period."

The time before bed tends to be a very anxious time for postpartum moms because there is this kind of fear of the unknown. A lot of them will talk about not wanting to go to sleep because they are afraid that as soon as they go to sleep the baby will wake up, and they will have to get up and take care of the baby. The sleep disruption that is out of their control just unhinges some women because they don’t know what to expect.

How might a sleep intervention help?

A major premise of my current line of research is that sleep would help with mood issues and that I think it is possible for sleep to improve, even during the perinatal period. I disagree with the hand waving that people get, being told, “Yep, you are the one who wanted to be a mom or a dad. Better get used to it.”

One of the main things we do is teach people about sleep and circadian rhythms and how the physiology works. One thing that thwarts women’s best efforts for getting good postpartum sleep is they are told, “Sleep when the baby sleeps.” Babies don’t have a circadian clock until they are 6 to 10 weeks old, whereas women who are of childbearing age have strong biological rhythms. So for a woman who is exhausted and tries to sleep at 11 in the morning, sleep may not come then — and if you are already depressed or anxious and exhausted and then you finally think you are going to get some rest, and you can’t because your body isn’t programmed to sleep at that time, imagine how demoralizing that is.

In my study we give people strict bedtimes and wake times. Not that they have to follow it with military precision, but it’s a prescription that is meant to fit into what their lifestyle is, such as when they have to get up to get their other kids to school or what time they have to get up to go to work. What it’s meant to do is to set a time for sleeping because we know from insomnia research that if you can compress your sleep into the nighttime hours, you’ll get deeper sleep and more sleep continuity. If you wake up in the night to use the bathroom — the most common thing that wakes pregnant women, particularly in the second and third trimester — the ease with which women can go back to sleep when they have their inevitable wakeups is better.

Another thing we do is to use light boxes in the morning to really give a strong signal to the brain for daytime vs. nighttime. The biological clock can get thrown off in these women because they are up so much in the middle of the night. Day blends into night. There’s this arrhythmic infant you are being asked to care for, but our theory is that keeping your own rhythm going during that time —rather than succumbing to the infant’s non-24-hour rhythm — is protective.

Women do have to get up to take care of the baby at night. The intervention that we are doing now starts in pregnancy with the idea that we may be teaching them skills and getting things as shored up as they can be prior to the postpartum, and teaching them the tips and tricks. We teach what to expect from the baby. One thing that is abundantly clear is that new moms are different than experienced moms. There are things that women learn that first time around that make it easier the second time around.

The other thing I will say is that it’s important for people in general to know about sleep and that we try to teach pregnant and postpartum women is that your day is not just a product of your sleep the night before. If we can get people on a consistent schedule where their bodies know when to expect sleep, then (a) we think that once they are done caring for the baby they will fall back to sleep more quickly, and (b) if they have a bad night here and there, if they’ve been on a decent schedule with at least some chunks of good sleep every night, that will play forward.

Give us some Mother’s Day hope. What are you finding so far?

We’re finding that women who become night owls during pregnancy don’t tend to do as well postpartum. In the cases that we’ve studied, we measured the circadian clock and its relationship to sleep both in pregnant and postpartum, and we found that the women who do best are women who once their biological clock says it’s time for bed, go to sleep. They go to sleep as soon as it’s biological feasible for them to do so.

We’re definitely finding that we can improve sleep. The study is still ongoing but when I watch a woman’s sleep efficiency — the amount of sleep that she’s getting during the time she’s in bed — actually go up across pregnancy as they are getting closer to delivery, that makes me feel that it really is possible to improve sleep at a time where conventional wisdom says, “Ah, it’s just going to get worse, and then it’s going to get even worse after that.”

Then there is animal data that shows that depending on what kind of sleep schedule you put a pregnant rat on, it has an effect on how the rat pups sleep and respond to circadian rhythm cues like light. That what is coming down the pike for me — if you can get a pregnant mom on a really good sleep schedule, does that somehow transfer to baby and result in a baby that’s a better sleeper?