During pregnancy, women with polycystic ovary syndrome (PCOS) display high circulating androgen levels that may affect the fetus and increase the risk of mood disorders in offspring. This study investigated whether maternal androgen excess causes anxiety-like behavior in offspring mimicking anxiety disorders in PCOS. The PCOS phenotype was induced in rats following prenatal androgen (PNA) exposure. PNA offspring displayed anxiety-like behavior in the elevated plus maze, which was reversed by flutamide [androgen receptor (AR) blocker] and tamoxifen [selective estrogen receptor (ER) modulator]. Circulating sex steroids did not differ between groups at adult age. The expression of serotonergic and GABAergic genes associated with emotional regulation in the amygdala was consistent with anxiety-like behavior in female, and partly in male PNA offspring. Furthermore, AR expression in amygdala was reduced in female PNA offspring and also in females exposed to testosterone in adult age. To determine whether AR activation in amygdala affects anxiety-like behavior, female rats were given testosterone mi-croinjections into amygdala, which resulted in anxiety-like behavior. Together, these data describe the anxiety-like behavior in PNA offspring and adult females with androgen excess, an impact that seems to occur during fetal life, and is mediated via AR in amygdala, together with changes in ERα, serotonergic, and GABAergic genes in amygdala and hippocampus. The anxiety-like behavior following tes-tosterone microinjections into amygdala demonstrates a key role for AR activation in this brain area. These results suggest that maternal androgen excess may underpin the risk of developing anxiety disorders in daughters and sons of PCOS mothers. maternal androgen excess | anxiety | behavior | polycystic ovary syndrome | amygdala P olycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by excessive androgen secretion and abnormal insulin activity and affects up to 17% of women worldwide (1). Women with PCOS are at an increased risk of developing symptoms of anxiety and depression. In fact, over 60% of women with PCOS are diagnosed with at least one psychiatric disorder, such as depression, anxiety, or an eating disorder (2). Suicide attempts have also been shown to be seven times more common in women with PCOS than in healthy controls (3). The mechanisms underlying the development of PCOS are poorly understood. Although a genetic basis for PCOS has been suggested, the intrauterine milieu might also affect the reproductive/endocrine function of a child born to a PCOS mother in a manner that is independent of genetic inheritance or sex. It is also known that daughters of mothers with PCOS are at increased risk of developing the syndrome and that sons tend to suffer from obesity and insulin resistance (4). Thus, it has been proposed that PCOS originates during fetal development and that this might be, in part, a result of maternal androgen excess (5). Maternal testosterone levels in humans have been shown to affect brain morphology and function (6) and to be correlated to neural development and mental function (7). There is evidence for a crucial role of the hippocampus and the amygdala in the development of anxiety and depression, and that these neural circuits are affected by fluctuations in sex steroids in humans and in rodents (8). We have previously demonstrated that continuous exposure to dihydrotestosterone (DHT) from puberty until adulthood in female rats down-regulates androgen receptor (AR) expression in the hy-pothalamus and induces anxiety-like behavior in female rats (9). The increased rates of anxiety disorders and disruptive behavioral disorders among children with genetically induced hyperandrogenism further indicate that androgen excess may contribute to a higher risk of psychopathology (10). During pregnancy, androgens are metabolized to estrogens by the placenta in women and by the ovaries in rodents. Thus, the effects of testosterone on pregnancy are partly mediated by es-trogen (11). Women with PCOS exhibit high circulating androgen levels during pregnancy, which hypothetically could be related to the increased risk of mood disorders in their offspring (12). Significance Polycystic ovary syndrome (PCOS) is the leading cause of anovu-latory infertility characterized by excessive androgen secretion. PCOS women are at an increased risk of developing depression and anxiety disorders. Although the etiology of PCOS is unclear, it is proposed to originate during fetal development because of maternal androgen excess. We describe here, in rodent models reflecting the anxiety phenotype of PCOS, evidence for disordered androgen receptor function in the amygdala, together with changes in estrogen receptor-α, serotonergic and GABAergic genes in the amygdala, and hippocampus. These findings define a previously unknown mechanism that may be critical in understanding how maternal androgen excess has the potential to increase the risk of developing anxiety disorders in daughters and sons of PCOS mothers.