The above advice is given by the The National Institutes of Health [NIH]. This is the link to the full advice given by NIH:
https://www.nichd.nih.gov/health/topics/autism/conditioninfo/treatments/medication-treatment
NIH make no mention that “imbalances in the body’s chemical systems” is based on a THEORY. A theory that remains unproven. It is concerning that the primary USA agency for biomedical and public health research does not make this clear.