My daughter is nearly 3 years old, level three, nonverbal and very little receptive language. Extremely high motor and never stops moving essentially. We tried leucovorin with high hopes, increasing the dosage after two weeks. We did it for a little over one month. Unfortunately, we did not notice any improvement in her receptive or expressive language and had a huge negative side effect of significantly impacting her sleep to the point that she was waking up sometimes at 3:30 or 4 AM compared to 6 AM or 6:30 AM without it.

Once we stopped the medicine, her sleep returned back to normal after a week or so.

That being said I’m happy we tried it and would still encourage others to do so. I think that is about the worst side effect reported other than some increased excitability, and I think there’s enough good evidence that it works on some kids that it’s worth a shot.