Abstract: Use is provided for a 7&agr;-hydroxy or 7-oxo substituted 3&bgr;-hydroxy-steroid possessing the carbon skeleton of cholesterol, androsterone, pregnenolone or estradiol, or an analogue thereof substituted independently at one or both of the 7- and 3-positions with an ester or ether group, in the manufacture of a pharmaceutical composition for the therapy of neuropsychiatric, immune and/or endocrine disorders or for inducing cognitive enhancement. Uses for Cyp7b enzymes in producing such steroids is also provided together with various novel steroids and test kits and methods for diagnosing the disorders.