TLDR Finasteride worsens stress effects on sensory processes, possibly linking to anxiety/depression.
The study investigated the effects of acute swim stress on prepulse inhibition (PPI) response in rats and found that finasteride administration, which decreases the levels of the neurosteroid allopregnanolone (ALLO), can increase the negative effects of stress on sensory gating processes. The study suggests that the maintenance of adequate levels of plasma and/or brain ALLO levels can be protective against the deleterious effects of environmental stress. The study also suggests a possible linkage to mood disorders such as anxiety/depression that have been reported in post-finasteride syndrome patients.
17 citations
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September 2013 in “The International Journal of Neuropsychopharmacology” 
73 citations
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July 2013 in “The Journal of Sexual Medicine” Finasteride use changes brain chemicals, causing lasting sexual issues and anxiety/depression.
18 citations
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January 2013 in “Psychoneuroendocrinology” 24 citations
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December 2012 in “Behavioural Brain Research” 42 citations
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August 2012 in “Psychoneuroendocrinology” 
134 citations
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August 2012 in “The Journal of Clinical Psychiatry” Former finasteride users with persistent sexual side effects have higher rates of depression and suicidal thoughts.
35 citations
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September 2009 in “Psychoneuroendocrinology” 64 citations
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March 2008 in “Neuropsychopharmacology” 
61 citations
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January 2008 in “Biological & Pharmaceutical Bulletin” Finasteride almost fully depletes allopregnanolone in rat brains and enhances 20α-DHP, but doesn't change 3α-DHP levels.
98 citations
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April 1997 in “The Journal of Steroid Biochemistry and Molecular Biology” Finasteride effectively blocks rat enzymes, but with varying methods and strength.
6 citations
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April 2015 in “Behavioural Brain Research” Finasteride worsens stress effects on sensory processes, possibly linking to anxiety/depression.
18 citations
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January 2013 in “Psychoneuroendocrinology”
