Part 1: Why Mood and Sleep Changes Are Often the First Sign of Perimenopause
By Guest Blogger: Kelley DeFilippis, CRNP, MSN, NP-C, Menopause Specialist, Owner/Founder of The Menopause Wellness Center
A woman in her 40s may begin experiencing anxiety that seems to come from nowhere. She may feel unusually irritable, emotionally overwhelmed, or unlike herself. She may fall asleep easily but wake at 2:00 or 3:00 in the morning with a racing mind, unable to return to sleep.
Because her periods are still regular and she isn't having hot flashes, neither she nor her clinician may think to consider perimenopause. Yet changes in sleep, mood, anxiety, and emotional resilience can be among the earliest signs of the menopause transition, often appearing before periods change or hot flashes begin.
For many women, the first sign of perimenopause isn't a missed period. It's the feeling that something has changed in their brain.
A Neurological Transition, Not Just a Reproductive One
Menopause is often described as the end of a woman's reproductive years, but it's just as much a neurological transition as a reproductive one. Estradiol and progesterone affect brain regions involved in mood, sleep, memory, and stress response, not just reproduction.
During perimenopause, these hormones don't decline smoothly. Estradiol can spike and drop unpredictably while progesterone gradually decreases, and the brain has to continually adjust to these shifting signals. For women who are especially sensitive to these changes, that instability can show up as anxiety, irritability, low mood, disrupted sleep, and a reduced ability to manage stress.
Symptoms That Can Show Up Before the "Classic" Signs
Many women are taught to watch for hot flashes and irregular periods as the first signs of perimenopause. But mood and sleep changes often show up earlier. A woman may still have predictable cycles while experiencing:
New or worsening anxiety
Irritability or a shorter temper
Low mood, frequent crying, or emotional sensitivity
Feeling overwhelmed by things she used to handle easily
Loss of motivation or pleasure
Trouble concentrating or brain fog
Trouble falling or staying asleep, or early-morning waking
Panic symptoms or a racing heart
A sense of "not feeling like herself"
These symptoms shouldn't automatically be blamed on hormones. Thyroid problems, anemia, sleep apnea, depression, anxiety disorders, and major life stress all need to be considered too. But perimenopause should be part of that conversation, especially between ages 35 and 55, or when symptoms track with the menstrual cycle.
Why the Risk of Depression Rises During This Transition
Research consistently shows that the menopause transition carries a higher risk of depression. In one major long-term study, women without any prior depression history were about twice as likely to develop significant depressive symptoms once they entered perimenopause, compared to women who hadn't yet started the transition. A 2024 review of more than 9,000 women found similar results.
Women with a past history of depression, anxiety, PMDD, postpartum depression, severe sleep disruption, or major life stress during this time may be especially vulnerable. This doesn't mean symptoms are "just hormones." It means biology, sleep, mental health, and life circumstances all deserve to be looked at together.
Sleep Is Both a Symptom and a Multiplier
Sleep disruption is one of the most common, and most underestimated, symptoms of this transition. You don't need night sweats to experience hormone-related sleep problems. Many women simply have lighter sleep, more frequent waking, or racing thoughts at 2 or 3 a.m.
Poor sleep tends to make everything else harder: anxiety, irritability, mood, and concentration. This creates a cycle where disrupted hormones affect sleep, and poor sleep makes the mood and cognitive symptoms even more difficult to manage.
You Are Not Losing Yourself
If you're experiencing new anxiety, low mood, irritability, or poor sleep in your late 30s, 40s, or early 50s, these symptoms deserve a real evaluation. They shouldn't be brushed off as aging, stress, or something you simply have to push through.
You are not failing to cope. Your brain and body may be responding to a major hormonal transition, and help is available.
In Part 2, we'll look at a hormone that rarely comes up in menopause conversations, but plays a real role in mood, motivation, and desire: testosterone.
If you are experiencing thoughts of suicide or self-harm, seek immediate help by calling or texting 988 in the United States, calling emergency services, or going to the nearest emergency department.
Selected References: Cohen et al., Archives of General Psychiatry (2006); Badawy et al., Journal of Affective Disorders (2024); Gracia & Freeman, Obstetrics and Gynecology Clinics of North America (2018); Kravitz et al., Sleep (2008).
This series is for general education and is not a substitute for individualized medical or psychiatric care. Hormone therapy and psychiatric treatment should be selected through an individualized assessment of symptoms, medical history, risks, preferences, and treatment goals.