The present disclosure is directed to a method of treating a neuropsychiatric disorder. This method involves selecting a subject having the neuropsychiatric disorder and administering to the selected subject a preparation of glial progenitor cells at a dosage effective to treat the neuropsychiatric disorder in the subject. Another aspect of the disclosure is directed to a method of treating a neuropsychiatric disorder that includes selecting a subject having the neuropsychiatric disorder and administering, to the selected subject, a potassium (K+) channel activator at a dosage effective to restore normal brain interstitial glial K+ levels in the selected subject and treat the neuropsychiatric disorder is also disclosed.