Sex steroids play very important roles in the development and function of the central nervous system and have long been known to exert powerful effects on brain differentiation, neural plasticity, central neurotransmission and behavior. Estrogens, progestins, and androgens are able to induce several effects in brain areas of the central nervous system, through binding with specific receptors (1). Sex steroid hormones act through genomic mechanisms, modulating synthesis, release and metabolism of many neuropeptides and neurotransmitters, and through non-genomic mechanisms, inşuencing electrical excitability, synaptic function, morphological features and neuron-glia interactions (2).
Animal research has shown that estrogens, progesterone and testosterone are critically involved in myelination, forming the basis of white matter connectivity in the central nervous system. Animal studies have also provided evidence that estrogen modulates dopaminergic activity and affects dopamine related behaviors in animals in a variety of ways.
Clinical observations suggest that sex steroids have potent effects on mood, mental state and cognitive functions. Data also suggest that estrogen has a pivotal role in modulating other neurotransmitter systems such as serotonergic and glutamatergic systems that have implications for schizophrenia and mood disorders (3,4). Sex steroid deficiency causes many neuroendocrine changes. At the hypothalamic level, estrogen withdrawal gives rise to vasomotor symptoms, eating behavior disorders, and altered blood pressure control. On the other hand, at the limbic level, the changes in serotoninergic, noradrenergic and opioidergic tones contribute to modifications in mood, behavior and nociception.
Studies of testosterone concentrations in depression have yielded inconsistent results reporting low as well as high testosterone levels associated with depression (5). On the other hand anabolic steroid use has increased in prevalence in many countries over the past decade, and it can lead to aggression, depression, mania and psychosis, in addition to a range of physical complications which seem to be important in clinical practice (6).
References:
1. McEwen BS Steroid hormones are multifunctional messengers to the brain. Horm Res. 1992; 37(Suppl 3):1-10.
2. Genazzani A.R. et al. Endocrinology of Menopausal Transition and Its Brain Implications CNS Spectr. 2005 Jun;10(6):449-57.
3. Janice R, Stevens MD Schizophrenia: reproductive hormones and the brain. Am J Psychiatry 2002; 159:713-719.
4. Seeman MV. The role of estrogen in schizophrenia. J Psychiatry Neurosci 1996; 21:123-125.
5. Zarrouf FA, Artz S, Griffith J, Sirbu C, Kommor M. Testosterone and depression: systematic review and meta-analysis. J Psychiatr Pract 2009;15:289-305.
6. Hall, R. C. W., Hall, R. C. W. & Chapman, M. J. Psychiatric complications of anabolic steroid use. Psychosomatics, 2005; 46- 285.