Mental dysfunction is not based on some structural distortion, such as a lump or an obstruction which, once developed, does not go away. Mental illness comes & goes repeatedly.

Sex hormones are critically important for the maintenance of a normal mind but are equally involved in the development of mental illnesses.

I remember some years ago looking up the definition of major depressive disorder (MDD).  The book described major depression as a "psychiatric disorder" characterized by a set of typical symptoms, which it went on to describe in some detail.

Mood disorders including unipolar & bipolar depression & generalized anxiety disorder are exquisitely sensitive to sexual, thyroidal & adrenal hormones.