"Hormone replacement therapy treatments 'can prevent depression in menopausal women'," reports the Daily Mirror.
Researchers in the US found women who took HRT for a year were less likely to develop symptoms of depression during that time than those who took a placebo.
Women going through menopause are at higher risk of depression.
Previous small studies have shown that hormone replacement therapy (HRT) can help treat depression in women going through menopause.
This study of 172 women aged 45 to 60 is the first to find that HRT may help prevent depression occurring in the first place in this group.
Half the women taking part in the study were given HRT and half were given a placebo treatment (a fake medicine).
The researchers found 32.3% of women who took a placebo scored highly on a depression symptom score at least once during the year of study, while 17.3% of women who took HRT reached the same depression symptom scores.
If the study can be repeated in a larger group of women, HRT could be an option for preventing depression in menopausal women.
The researchers speculated that HRT may help regulate hormone levels – previous research has linked fluctuating hormone levels (specifically the hormone oestradiol) to depression.
Women taking HRT were more likely than those taking a placebo to experience spotting or moderate or heavy vaginal bleeding.
This may be a factor for some women when deciding whether or not to take HRT.
HRT is also known to slightly raise the risk of breast cancer and blood clots in the veins.
But though these risks need to be taken into account, they're very small, and most experts argue they're usually outweighed by the benefits of HRT.
Read more about the risks associated with HRT.
The study was carried out by researchers from the University of Regina in Canada and the University of North Carolina and the National Institute for Mental Health in the US.
It was funded by grants from the National Institutes of Health and was published in the peer-reviewed journal JAMA Psychiatry on an open access basis, so it's free to read online.
The Mail Online and Daily Mirror gave a reasonable overview of the study, but the Mail Online didn't mention side effects and the Mirror only mentioned bleeding.
Surprisingly, neither of the news stories considered the potential increase in risk of breast cancer with HRT.
This was a double-blinded randomised controlled trial, which is the best sort of study to see whether a treatment works.
Researchers recruited 172 women aged 45 to 60 who were in perimenopause (the "pre-menopausal stage", usually lasting a period of a few years where the ovaries gradually stop producing oestrogen) or early post-menopause, and didn't have depression at the start of the study.
Half were randomly selected to be given oestrogen patches and progesterone pills, while the others took placebo patches and pills.
The study lasted a year, during which time the women were questioned about their mood every 2 months using a standard depression questionnaire.
The researchers then looked for differences in depression symptom scores between the 2 groups, and considered whether other factors affected the results.
Women in the treatment group were given skin patches of 0.1mg a day of oestradiol, plus tablets of 200mg progesterone to be taken for 12 days every 3 months. Progesterone is given along with oestradiol to protect against the risk of womb cancer.
The depression symptom score used was the Center for Epidemiological Studies Depression Scale, which runs from 0 to 80.
People are considered to be at risk of depression if they have a score of 16 or over. We refer to this as a high depression symptom score.
Researchers looked at the following factors to see if they had an effect on treatment outcome:
Of the 172 women in the study, 43 (25%) had a high depression symptom score (suggesting they may have had depression) at least once during the year.
This was more common for women taking the placebo than women taking HRT:
HRT reduced the chances of a high depression symptom score for women in early menopause, but not late or post-menopause – women with a history of stressful life events were more likely to benefit from treatment.
Perhaps surprisingly, menopausal symptoms like hot flushes didn't affect the chances of benefiting from treatment.
Women were more likely to get irregular vaginal bleeding if they took HRT. One woman taking HRT developed a blood clot in a leg vein (deep vein thrombosis).
The researchers pointed out that their study confirms that women going through the menopause "are at high risk for developing clinically significant depressive symptoms".
They said their study is the first to show that HRT "prevents this transition-related increase in risk for depressive mood".
They also said doctors should be "alert to the high risk for clinically significant depressive symptoms" in women going through early menopause and that – if their findings are repeated in a larger study – they should "consider using [HRT] as a prophylactic [protective] treatment in the prevention of clinically significant depressive symptoms" in women eligible for treatment.
The effects of the menopause vary widely from one woman to another. Some women have few problems, whereas others are badly affected by symptoms like hot flushes, mood swings and depression.
A decision about whether to take HRT to ease menopausal symptoms is likely to be different for each woman.
Women can discuss the risks and benefits of treatment, and the different types of HRT available, with their GP.
This new study underlines the relatively high chances of having symptoms of depression while going through the menopause.
But it's not true to say that women in the study with high depression symptom scores all had depression, or that HRT prevented depression. Only 2 women in the placebo group were diagnosed with severe depression.
The study showed a big effect of treatment, although it was small. The results need to be confirmed in studies with larger populations to be sure the results are reliable.
The researchers reported that the HRT and placebo patches weren't identical, so some women might have known whether or not they were taking active treatment.
Also, the effects of active treatment on vaginal bleeding may have made women guess they were taking real HRT.
The potential for HRT to prevent symptoms of depression may seem an attractive option for women approaching the menopause.
But women going through the menopause are usually advised to take HRT only for as long as necessary to treat their symptoms.
That's because of the small increased risk of breast cancer, deep vein thrombosis and cardiovascular disease. Taking HRT to try to prevent depression may expose women to unnecessary risks.
If you're troubled by low mood, a good first step is to talk to your GP. They'll be able to discuss possible treatment options with you.