--- title: Can a hormone that usually reduces anxiety instead cause anxiety after your body adapts to its being blocked? description: Yes. When a hormone precursor was blocked, the hormone THP (which normally calms anxiety) instead increased anxiety in female mice. This effect involved chang url: https://niyora.com/research/papers/steroid-withdrawal-in-the-mouse-results-in-anxiogenic-effects-of-3alpha-5beta-2006/ --- - [Niyora](https://niyora.com/) - [Research](https://niyora.com/research/) - [Library](https://niyora.com/research/library/) - Can a hormone that usually reduces anxiety instead cause anxiety after your body adapts to its being blocked? Lab study, 2006 # Can a hormone that usually reduces anxiety instead cause anxiety after your body adapts to its being blocked? Yes. When a hormone precursor was blocked, the hormone THP (which normally calms anxiety) instead increased anxiety in female mice. This effect involved changes to specific brain receptors. Early or limited evidence Female wild-type and delta knockout mice ## What they did Researchers gave female mice a drug called finasteride for 3 days to block production of a steroid hormone. Then they tested the mice in a maze where anxious mice avoid open spaces. They also measured changes in brain receptors to see what had changed. ## What they found After hormone blockade, THP caused anxiety instead of reducing it. The mice avoided open spaces more than expected. The researchers found increased levels of a specific brain receptor (alpha4 subunit) in the hippocampus. When they tested mice lacking this receptor type, the anxiety effects disappeared. ## What it means for you Changes in brain receptors from low hormone levels might flip how certain hormones and drugs affect anxiety, which could explain some PMDD symptoms. The brain receptor change might be a key mechanism. This is a laboratory mouse study modeling one possible mechanism in PMDD, but not a study of women with the disorder. 3 days finasteride treatment ## About the study Original title Steroid withdrawal in the mouse results in anxiogenic effects of 3alpha,5beta-THP: a possible model of premenstrual dysphoric disorder Authors Smith SS, Ruderman Y, Frye C et al. Journal Psychopharmacology Year 2006 Study design Lab study What was tested Finasteride to block hormone production, then THP and other drugs Open access Yes Read the paper [doi.org/10.1007/s00213-005-0168-3](https://doi.org/10.1007/s00213-005-0168-3) ## Topics [Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Premenstrual dysphoric disorder (PMDD)](https://niyora.com/research/topics/condition-pmdd/)[Low mood and depression](https://niyora.com/research/topics/symptom-depression-mood/)[Anxiety and tension](https://niyora.com/research/topics/symptom-anxiety/)[Neurosteroids (allopregnanolone)](https://niyora.com/research/topics/treatment-neurosteroids/)[Anxiolytics and other psychotropics](https://niyora.com/research/topics/treatment-anxiolytics/)[Pregnancy and postpartum](https://niyora.com/research/topics/comorbidity-postpartum/) Research tells you what helps on average. Niyora helps on the day it hits. Calm down, see it another way, and decide what to say, with a PMS and PMDD app built by a doctor. ## Related studies Review, 2003 How do menstrual cycle hormones affect the brain and cause mood disorders like PMDD? Randomised trial, 2017 Does Sepranolone reduce symptoms of severe premenstrual syndrome (PMDD)? Review, 2010 Can neurosteroids help with anxiety and brain disorders? Case-control study, 2026 What role do brain chemicals called neurosteroids play in PMDD? Case-control study, 2025 Do certain hormone-related brain chemicals predict how bad premenstrual depression and anxiety will be? Review, 2022 Can blocking a natural brain steroid help PMDD? Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗