Davis Van Dyk / Psychology / Faculty Mentor: Linda Perrotti

Opioid withdrawal induces anxiety, which influences continued use. With extensive research demonstrating conflicting gender findings and there being a lack of research in the estrous cycle’s role in withdrawal-induced anxiety, this study investigates anxiety during opioid withdrawal in Long Evans rats, considering estrous cycle stage. Rats received escalating morphine doses for ten days while controls received saline injections. Anxiety-like behaviors were evaluated using the elevated plus maze (EPM) 24 hours after the last morphine administration and female estrous cycle stages were monitored. The study revealed heightened anxiety-like behaviors in rats experiencing morphine withdrawal, with decreased open-arm entries and time spent in open arms, and increased closed-arm entries and time spent in closed arms compared to saline controls. Interestingly, proestrous/estrous females exhibited elevated anxiety during withdrawal compared to metestrous/diestrous stages and saline-treated females. This aligns with evidence linking sex differences in addiction-like behaviors to different levels of estradiol and progestin, which is important as a factor in opioid withdrawal-induced anxiety in females and for developing targeted interventions in opioid addiction treatment.

Video Presentation