However, it is only able to do so at micromolar concentrations, which, similarly to the case of the L-VGCCs, are far greater than the low nanomolar concentrations of allopregnanolone estimated to be present in the brain. Biphasic actions at the GABAA receptor
Increased levels of allopregnanolone can produce paradoxical effects, including negative mood, anxiety, irritability, and aggression. This appears to be because allopregnanolone possesses biphasic, U-shaped actions at the GABAA receptor – moderate level increases (in the range of 1.5–2 nmol/L total allopregnanolone, which are approximately equivalent to luteal phase levels) inhibit the activity of the receptor, while lower and higher concentration increases stimulate it. This seems to be a common effect of many GABAA receptor positive allosteric modulators. In accordance, acute administration of low doses of micronized progesterone (which reliably elevates allopregnanolone levels) has been found to have negative effects on mood, while higher doses have a neutral effect. Antidepressant effects
The mechanism by which neurosteroid GABAA receptor PAMs like brexanolone have antidepressant effects is unknown. Other GABAA receptor PAMs, such as benzodiazepines, are not thought of as antidepressants and have no proven efficacy, despite clinicians prescribing Alprazolam for depression in the past. Neurosteroid GABAA receptor PAMs are known to interact with GABAA receptors and sub-populations differently than benzodiazepines. As examples, GABAA receptor-potentiating neurosteroids may preferentially target δ subunit-containing GABAA receptors, and enhance both tonic and phasic inhibition mediated by GABAA receptors.
The differential diagnosis of a renal tumor in a young patient with hypertension includes Juxtaglomerular cell tumor, Wilms tumor, and renal cell carcinoma, all of which may produce renin. Hypertension secondary to other renal disorders
Chronic kidney disease
Kidney disease / renal artery stenosis –  the normal physiological response to low blood pressure in the renal arteries is to increase cardiac output (CO) to maintain the pressure needed for glomerular filtration.Here, however, increased CO cannot solve the structural problems causing renal artery hypotension, with the result that CO remains chronically elevated. Renal segmental hypoplasia (Ask-Upmark kidney)

Hypertension secondary to endocrine disorders
Neurogenic hypertension – excessive secretion of norepinephrine and epinephrine which promotes vasoconstriction resulting from chronic high activity of the sympathoadrenal system, the sympathetic nervous system and the adrenal gland. The specific mechanism involved is increased release of the "stress hormones", epinephrine (adrenaline) and norepinephrine which increase blood output from the heart and constrict arteries.