GPER1 and bipolar disorder: 2005, Walf et al. 2009). Recently, there has been an increased interest in animal studies on anxiety‐like behaviors about GPER and the GPER agonist G‐1. However, there are inconsistent results regarding whether GPER increases or decreases anxiety (Hart et al. 2014, Kastenberger et al. 2012, Kastenberger and Schwarzer 2014, Zheng et al. 2020). One study, by Fındıklı et al., reported increased serum GPER levels in GAD patients, and this pattern has also been observed in samples of people with schizophrenia and bipolar disorder (Fındıklı et al. 2016, Hursitoglu et al. 2020, Orhan et al. 2018).