AQP4 and myalgic encephalomeyelitis/chronic fatigue syndrome: Moreover, therapeutics (noradrenaline and specific serotonergic antidepressants) for GD and ME/CFS have been associated with increased astrocytes and upregulated AQP4 expression; these include ketamine [187,193] and mirtazapine (improves glial cell line-derived neurotrophic factor production) [65,186].