Allopregnanolone - Why You Feel Down When You’re Not In The ‘Normal Weight’ Category -

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There are days when you feel like you could jump out of bed at 6am and do just about anything, and there are days when it’s a struggle to drag yourself from under the duvet before 7.30am. Our mood is affected by a variety of external factors – general life stresses, lack of sleep, your diet – but it’s also determined by hormones.

Did you know that your body specifically produces a ‘feel good’ steroid that seriously increases feelings of well-being?

Allopregnanolone is a mood-affecting steroid and has previously been linked to feeling good, and in the same vein, depression and anxiety when at low levels.

However, a recent study has found that women who suffer from anorexia nervosa or obesity tend to have lower levels of the neurosteroid, making them more likely to suffer from depression or anxiety.

What is allopregnanolone?

Allopregnanolone, which scientists have thankfully nicknamed ‘allo’, is a metabolite of the female hormone, progesterone. Its job is to bind receptors for the the neurotransmitter gamma-aminobutyric acid (GABA) which are the receptors that anti-anxiety drugs target.

This enhances the signal produced when GABA binds to its receptor, and simply put, produces a positive mood and feelings of well-being.


How is a low level of allopregnanolone linked to obesity and anorexia nervosa?

A study published in the journal Neuropsychopharmacology examined the link between low levels of allo and individuals who were obese or anorexic.

It states that 50% of women with anorexia have depression or anxiety, and 43% of adults who are obese have depression.

While previous studies have linked low levels of allo to depression, anxiety and PTSD, this is the first time that the impact of this chemical on mood has been assessed in individuals suffering from anorexia or obesity.

“We are beginning to see more and more evidence that low allo levels are tightly linked to depression, anxiety, post-traumatic stress disorder and other mood disorders,” said Graziano Pinna, associate professor of psychiatry in the University of Illinois at Chicago College of Medicine and an author on the paper.

“To see that women with anorexia nervosa and obesity have low levels adds to the picture that the role of allo is under-recognized in mood disorders.”

Pinna’s colleagues, led by Dr. Karen Miller, professor of medicine at Harvard Medical School, selected the following participants for the study:

  • 12 women with anorexia and amenorrhea, with a BMI of less than 18.5
  • 12 women considered to be of ‘normal weight’ with a BMI between 19 and 24
  • 12 obese women with BMI 25+

None of the individuals had been clinically diagnosed with depression, but were asked to fill out a questionnaire to assess their mental health and detect symptoms of depression or anxiety. They also had blood samples taken which were tested for their levels of allo.

Allopregnanolone - Why You Feel Down When You’re Not In The ‘Normal Weight’ Category -

Interestingly, the results showed that the blood levels of allo were 50% lower in women suffering from anorexia or obesity when compared to the women with a healthy BMI.

The women who were clinically obese also showed allo levels 60% lower than the ‘normal weight’ women.

The results also suggests that those who presented severe symptoms of depression or anxiety had lower levels of allo, with researchers concluding that there is a distinct correlation between the level of allo and the severity of the mood disorders.

Across the board, the women in the study had low levels of progesterone, leading the researchers to conclude ‘that the decrease in allo in participants with anorexia nervosa and obesity may have been caused by improper functioning of enzymes responsible for the metabolism of progesterone into allo.’

“Depression is an incredibly prevalent problem, especially in women, and also particularly at the extremes of the weight spectrum,” said Miller. “The hope is that a greater understanding of mechanisms contributing to these disorders — including abnormalities in the regulation of hormones and their neuroactive metabolites — may lead to new targeted therapies in the future.”

While the study selected individuals for each category based on their BMI, it’s worth noting that it’s not always an accurate measurement of health as it doesn’t take into account how much of your weight is muscle mass or fat.

Wondering if your diet can boost your mood? Take a look at Foods For Depression and The Drink That Fights Depression.


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