A causality dilemma: ARFID, malnutrition, psychosis, and hypomagnesemia

We present a novel case of a woman with coincident occurrence of auditory and visual hallucinations, electrolyte disturbances, chloride unresponsive alkalosis, and an eating disorder. The patient was ultimately diagnosed with Gitelman syndrome comorbid with schizophreniform disorder and avoidant restrictive food intake disorder. Eating disorders are often associated with electrolyte abnormalities which, in turn, can cause or contribute to other neuropsychiatric symptoms. At the same time, psychotic disorders can lead to food intake aversions or overconsumption of fluids with associated effects on electrolyte balance. In this case, a third factor, Gitelman syndrome, resulted in persistent hypomagnesemia with metabolic alkalosis and, while separate from her eating disorder, simultaneously reinforced the patient's strong food preferences, excessive fluid intake, and excessive movement related to her complaints of persistent joint pain.