When Perimenopause Is More Than Mood Swings: The Link With Bipolar Disorder

Mood swings and perimenopause.  They seem to go together like hot flushes and throwing the duvet off at 3am.  One minute you're perfectly fine.  The next you're crying at an advert involving a dog.  Then somebody breathes too loudly and you briefly consider moving to a remote cottage where nobody can ever speak to you again.

Hormonal changes really can affect mood during perimenopause.  But new attention on women's mental health is highlighting something much more serious — and much less talked about.

For some women, the years around menopause may also be a period when serious mental illnesses such as bipolar disorder first emerge or existing conditions become harder to manage.

In 2026, the Royal College of Psychiatrists issued its first position statement specifically addressing menopause and mental health, warning that this relationship has historically been overlooked.

And one statistic in particular has attracted attention:

Research found a 112% increase in the incidence of bipolar disorder during perimenopause.

That sounds frightening.  So let's look at what it actually means — and, equally importantly, what it doesn't mean.

First: perimenopause does not mean you're going to develop bipolar disorder

This needs saying right at the beginning.  Feeling irritable, anxious, emotional or unlike yourself during perimenopause doesn't mean you have bipolar disorder.

Bipolar disorder is a serious mental health condition involving significant episodes of depression and periods of unusually elevated or irritable mood known as mania or hypomania.

It isn't the same thing as everyday mood swings.  And the research doesn't show that perimenopause simply causes bipolar disorder.  What researchers have found is an association between the hormonal transition around menopause and an increased rate of first diagnoses of certain psychiatric conditions.

That's a very different claim.

Where did the 112% figure come from?

Researchers at Cardiff University, working with Bipolar UK, analysed data from 128,294 women in the UK Biobank.

They wanted to answer a fascinating question:  Could the hormonal changes around menopause influence the first onset of serious mental illness?

They examined diagnoses during the four years surrounding women's final menstrual period and compared them with the years before menopause.  The biggest change they observed was in bipolar disorder.

The incidence of bipolar disorder increased by 112%.

Major depressive disorder increased by 30%. Cardiff University

Professor Arianna Di Florio, who led the research, said the study was inspired partly by women she had encountered clinically who had previously lived without severe mental-health problems and then developed serious illness around menopause. Cardiff University

That makes this an important finding.  But there's something crucial to understand about that percentage.

A 112% increase doesn't mean 112% of women develop bipolar

Absolutely not.  It's a relative increase in incidence between the periods researchers compared.

Bipolar disorder remains much less common than ordinary perimenopause symptoms such as irritability, anxiety, sleep disturbance and low mood.

So this research shouldn't make every woman who's shouted at her husband and then cried because there was no milk left wonder whether she's developing bipolar disorder.

What it does suggest is that perimenopause may represent a period of increased vulnerability for some women.

And that matters because symptoms need to be recognised.

Why might hormones affect mental health?

We don't yet have the complete answer.  During perimenopause, levels of hormones including oestrogen don't simply decline smoothly.  They can fluctuate considerably.  Oestrogen interacts with several systems in the brain, including neurotransmitters involved in mood, cognition and emotional regulation.

Then add everything else perimenopause can bring:

• Poor sleep.
• Night sweats.
• Physical symptoms.
• Changes in relationships.
• Work pressure.
• Caring responsibilities.
• Children leaving home — or somehow still requiring a taxi service at 21.
• Ageing parents.
• Changes in confidence.

Sometimes all at once.  It's therefore difficult to separate the biological, psychological and social factors completely.

Researchers are increasingly arguing that reproductive transitions — including menstruation, pregnancy, the postnatal period and menopause — deserve much more attention within mental-health care.

The Royal College of Psychiatrists now says menopause can be associated not only with anxiety, depression and cognitive changes but, in some cases, with the triggering or worsening of serious mental illness. www.rcpsych.ac.uk

So what's the difference between perimenopause mood swings and bipolar disorder?

This is probably the question many women will have.  Because perimenopause can make you feel very unlike yourself.

Typical perimenopause mood changes can include:

• Irritability.
• Anxiety.
• Feeling overwhelmed.
• Low mood.
• Tearfulness.
• Reduced resilience.
• Difficulty concentrating.
• Poor sleep.
• Changes in motivation.

These can be miserable and disruptive.  But mania or hypomania involves a more distinct change in mood, energy and behaviour.

Possible symptoms can include feeling unusually energised or “high”, needing significantly less sleep without feeling tired, talking much more or much faster than usual, racing thoughts, feeling unusually confident or powerful, becoming much more impulsive, taking unusual risks or spending excessively.

With severe mania, a person may also experience psychotic symptoms such as delusions or hallucinations.  It's the degree of change, combination of symptoms, duration and impact on everyday life that matter.  And that's why bipolar disorder shouldn't be diagnosed from an online symptom checklist.

“But I've never had bipolar disorder before”

That's precisely why this research is interesting.  The Cardiff researchers weren't simply looking at women who already had bipolar disorder.  They specifically investigated first-onset psychiatric disorders around menopause. Cardiff University

For some women, therefore, the first obvious episode may happen in midlife.  That doesn't necessarily mean menopause single-handedly created the illness.  

There may be underlying genetic or biological vulnerability that hadn't previously resulted in a clinical episode.  Hormonal change could potentially be one of several factors that help bring that vulnerability to the surface.

Researchers still have a great deal to learn about exactly why this happens and which women are most susceptible.

What if I already have bipolar disorder?

This is another important part of the picture.

The Royal College of Psychiatrists says perimenopause may represent a period of particular clinical risk for women who have bipolar disorder or are vulnerable to it. The Guardian

There is also evidence that previous sensitivity to reproductive hormonal changes may be relevant.

Women with bipolar disorder who have experienced significant premenstrual mood symptoms or postnatal depression appear to have a greater risk of depressive relapse around menopause, according to evidence highlighted by the College. The Guardian

That raises a really interesting possibility:

Our previous responses to hormonal change may tell doctors something about how we'll respond to menopause.

It's an area researchers are still investigating.

And sleep could be particularly important

This one deserves more attention.  Perimenopause can absolutely destroy sleep.  Night sweats wake you up.  Hormonal changes may disrupt sleep.  Anxiety wakes you at 3am.

Then you can't get back to sleep because your brain decides this is the ideal moment to remember something embarrassing you said at a Christmas party in 2008.

But disrupted sleep is also particularly important in bipolar disorder.  Changes in sleep patterns can accompany or contribute to mood episodes.

So if you already have bipolar disorder and perimenopause is suddenly playing havoc with your sleep, it's worth discussing that with your mental-health team rather than simply accepting it as another menopause symptom.

Where does HRT fit into this?

This is where things become much less straightforward.  HRT can be highly effective for many menopause symptoms.

And if hot flushes, night sweats and disrupted sleep are contributing to poor mental wellbeing, successfully treating those symptoms could clearly make a difference to quality of life.

But HRT is not a treatment for bipolar disorder.

The evidence about how menopausal hormone therapy interacts with serious mental illness is still limited, and treatment needs to be individualised.

The Royal College of Psychiatrists has specifically called for better access to menopause assessment and treatment — including HRT where appropriate — for women with mental illness, rather than having physical and mental healthcare treated as completely separate issues. www.rcpsych.ac.uk

That's an important distinction.

It shouldn't be:

“Is this menopause OR mental health?”

Sometimes both need considering.

The problem of everything being blamed on one diagnosis

There's another issue the College has highlighted: diagnostic overshadowing.  Imagine you've already been diagnosed with bipolar disorder.  

You reach your 40s and develop:

• Hot flushes.
• Night sweats.
• Brain fog.
• Sleep problems.
• Anxiety.
• Changes in mood.

But because you already have a psychiatric diagnosis, every new symptom is attributed to your mental health.  The menopause gets missed.  The reverse can happen too.

A woman experiencing significant psychiatric symptoms in her 40s may assume:  It's just menopause.

And a potentially serious mental-health problem could therefore be overlooked.  The answer isn't to assume one or the other.

It's to consider both.

Why haven't we heard more about this?

That's a good question.  The Royal College of Psychiatrists commissioned YouGov polling as part of its 2026 work and found that only 28% of UK women knew a new mental illness could be associated with menopause. The Guardian

Compare that with almost everybody knowing about hot flushes.  We've become dramatically better at talking about menopause over the past few years.

But much of the conversation still revolves around a familiar collection of symptoms:

• Hot flushes.
• Weight changes.
• Brain fog.
• Sex drive.
• Sleep.
• Mental health is often reduced to “you might feel a bit anxious or emotional.”

For some women, it can be considerably more serious than that.

When should you ask for help?

If your mood or behaviour changes substantially during perimenopause — particularly if the change feels completely out of character — don't automatically assume you just have to ride it out.  Talk to your GP.

It's particularly important to seek professional advice if you're experiencing things such as:

• needing dramatically less sleep than usual
• unusually high energy lasting for days
• racing thoughts or very rapid speech
• feeling unusually powerful, invincible or excessively confident
• significant impulsivity or risk-taking
• spending or behaving in ways that are very unlike you
• severe depression
• hallucinations, delusions or losing touch with reality.

If you already have bipolar disorder and notice your symptoms changing as you enter perimenopause, talk to your psychiatrist, GP or mental-health team.

And don't change psychiatric medication or HRT without medical advice.

If you feel you may harm yourself or someone else, or you're experiencing severe mania or psychosis, seek urgent medical help rather than waiting for a routine appointment.

The Hot Again take

We talk a lot about women being told:  “It's just your hormones.”

And quite rightly.  Women shouldn't have every health problem dismissed as menopause simply because they're in their 40s or 50s.  But there's another side to that conversation.

We shouldn't dismiss serious changes in mental health as “just hormones” either.  The Cardiff research doesn't tell us that perimenopause causes bipolar disorder.

It doesn't mean ordinary menopause mood swings are bipolar.  And it certainly doesn't mean women should start diagnosing themselves.  What it does tell us is that the relationship between our hormones and our brains is far more significant than medicine has historically acknowledged.

For a small number of women, perimenopause may coincide with the first appearance of serious mental illness.

For women already living with bipolar disorder, hormonal change may affect how well they've previously been able to manage their condition.

And for everyone else?  It's another reminder that menopause isn't simply about hot flushes and periods stopping.  Our brains are part of this transition too.

So if you're going through perimenopause and find yourself thinking:

“This isn't just a mood swing. I genuinely don't feel like myself.”

Don't be embarrassed to say so.

Don't assume you're overreacting.

And don't feel you need to work out whether it's hormones, mental health or both before asking for help.

It's not just you — and it's worth taking seriously.

Sources:
The Guardian's coverage: Three in four women unaware menopause can trigger new mental illness. 
Cardiff University
Royal College of Psychiatrists' menopause and mental-health statement