There is a wealth of evidence that many mothers experience the baby blues and post-partum depression after childbirth. But researchers have rarely studied the effect that weaning has on mom’s mood and well-being.

While you’re breastfeeding, your body is making more oxytocin, also known as the “love hormone.” Oxytocin is responsible for the muscle contractions that carry us through life: it plays a part in orgasm, birth, and breastfeeding. Truly amazing, complex stuff– and no wonder why the man-made copy, Pitocin, falls extremely short.

The window for postpartum depression has been greatly expanded in recent years, with studies showing that moms can experience symptoms starting just days or weeks after birth up to a year afterwards.

Scientists theorize that once the oxytocin levels return to pre-pregnancy levels after weaning, mom may experience a drop in mood levels because in addition to its contributions to creating life, oxytocin is also responsible for relaxation and psychological stability in our brains. But researchers don’t know for sure—because there is no data on oxytocin levels in women who wean naturally.

In 2012, a study was released linking depression with failed lactation, but that was centered around women who are forced to wean for one reason or another. Even then, it was hard for scientists to determine which problem was driving the other. Were these women weaning because the depression was too much, or was the weaning causing the depression? Most pregnancy research is baby-centered, admits Dr. Alison Stuebe, an OBGYN and assistant professor of maternal and child health at the University of North Carolina, who co-authored the study. “The mom kind of disappears from the radar” after that, she says. (Any new mom would probably agree that’s not just limited to research!)

Doctors say it’s normal to feel sad about the loss of the nursing relationship, even if you are ready to be done nursing. Many women say they feel tired, irritated, and sad, and experience mood swings similar to PMS.  These symptoms are completely normal and tend to disappear as quickly as they crop up. What you should watch for, say researchers, are symptoms that last more than a few days, change your daily activities, or your sleep patterns. If you don’t enjoy things that you used to, or find yourself lying awake at night when the kids are all sleeping peacefully, that should be a red flag.

I first became aware of post-weaning depression anecdotally. Mom friends from online group posted about having depressive symptoms, not after childbirth but after weaning, and I read a few mommy bloggers who talked about it. It was something I noted so I could be prepared for it with my second child. I hadn’t made it to a year with my first child, and hoped to nurse at least a year this time. However, I became pregnant when she was 10 months and she weaned in a few days when I started employing don’t offer/don’t refuse in a pregnancy panic. I was already awash with pregnancy hormones, and I never experienced weaning depression.

But now, I am in the process of weaning my third and final nursling. I’m not sure where in the process we are.

We moved a month after she turned one, so I committed to keeping it up for at least six more months so she could adjust completely to the change, and here we are at 18 months. Currently, she nurses first thing in the morning, and then on demand during the day. Sometimes it’s a few times, sometimes it’s just once that day. The sessions are very short and snacky, and she has to be extremely tired to actually nurse to sleep.

A month or two after she cut out regular pre-nap and pre-bedtime sessions in favor of reading books instead, I noticed a change in my mood. I would lose my temper and yell at the older kids. I didn’t want to go running, which I normally love to do. I quit caring if I got a shower or got dressed that day. I was putting off writing assignments until the last minute because I didn’t have the energy to do them. I felt hopeless and convinced that everything was going wrong in every area of my life. Sometimes I felt like everyone would be better off without me, even though I knew that wasn’t true. These feelings would last a day or two, and then I would feel like myself again.

I would love for someone to really study the effects of weaning on moms who wean naturally or purposefully. It’s confusing when you’re going through it because of how suddenly it stops and starts, and how the smallest thing can bring on such intense feelings. I feel crazy, because nursing is so hard, and you do look forward to not being confined to blocks of a few hours of freedom, to your children being independent and not needing you so much, and even to losing that layer of nursing fat that seems to hide all over your body. But then, when it comes down to really losing that relationship and never having that closeness again, it’s sad. It represents more than not nursing anymore; it’s you and your baby growing older and growing up.

I’m trying to work through my sporadic depression by taking the last placenta capsules saved from the birth of my last child, and committing to getting outside and running even when I have no desire to go. I know the sunshine, fresh air and the stimulation exercise gives my body will help. But at the same time, I am also committing to getting help and talking to someone if I can’t pull myself out of it, or if the symptoms last for more than a day or two.

If your child is weaning and you don’t feel like yourself, complete this depression checklist, which you can print and take with you to the doctor. Talk to your significant other, friends or family about how you are feeling, regardless of whether or not you think your feelings are warranted. If your doctor doesn’t understand, find one who will.

Erin Burt is a freelance writer and mother of three who lives and writes in Queensbury, New York.