A method treats patient with treatment resistant depression, adjunct to standard antidepressant treatment or as monotherapy. These patients will be identified by non-response to at least one pharmacological antidepressant treatment with a sufficient dose and over a sufficient period of time. Further, one embodiment of the method includes a procedure to identify patients who would benefit from a combination of standard antidepressants with the described compounds from the start of the treatment in order to maximize the likelihood of response. Another embodiment of the method combines the described compounds with forms of Magnesium salts in order to overcome longer term tolerability issues with the compounds. An important downstream mechanism of the described interventions is the property to reduce the production and/or increase the absorption of cerebrospinal fluid to treat a variety of symptoms, including cognitive dysfunction, memory loss, apathy, sleep disturbances, pain disorders, and somatoform pain and headache.