Neuroimaging Research in Women’s Mental Health: Current Research and Emerging Trends in Women and Transgender Women’s Psychiatry and Mental Health

Abstract

Women’s mental health seems to be affected by different factors and present with particular epidemiology when compared to men’s mental health. In terms of mood disorders, these include the age of onset, seasonal features, incidence of suicidal attempts, and typicality of features. One hypothesis is that the difference in sex hormones is considered to impact the epidemiology and the course of psychiatric disorders in women. For example, changes in the hormonal milieu that occur in the end of pregnancy have been linked to peripartum depression, and the fluctuations of sex hormones during the menstrual cycle have been linked to premenstrual dysphoric disorder (PMDD). Neuroimage research has contributed to identifying potential biomarkers in respect to these disorders. For instance, peripartum depression has been associated with a decreased activation of the limbic structures, as well as a decreased functional connectivity between frontal cortex and limbic structures, which seems to point out different pathophysiologic mechanisms for postpartum depression. Regarding PMDD, being diagnosed with bipolar disorder while experiencing this comorbidity is related to a more challenging course of bipolar disorder. This seems to be related to female sex hormones’ neuroactivity, since they were shown to affect the glutamatergic and GABAergic systems. According to the phase of the menstrual cycle, women with PMDD seem to exhibit different brain activation in the motor and somatosensory cortices. Complementarily, a cortical thickness study showed that PMDD women with bipolar disorder present with an increased cortical thickness of the left superior temporal gyrus, a decreased cortical thickness of the left parietal, and superior frontal and left pericalcarine cortices, including, resting-state functional connectivity (rs-FC) between the left hippocampus and right frontal cortex, as well as decreased rs-FC between right hippocampus and right premotor cortex. Although there are not many neuroimaging studies investigating the influence of “female” sex hormones in the brain, and therefore, their relationship with psychiatric symptoms in transgender women/transgender person should also be considered a population vulnerable to female sex neuroactive steroids influence.