Intolerance to milk proteins
There has been speculation if milk proteins may have a role in Attention Deficit Hyperactivity Disorder (ADHD), autism, depressions and schizophrenia in some cases.
There are major supports to the hypothesis that ADHD may be linked to increased levels of neuroactive peptides and increased urinary peptide levels [158,159]. A diet free
of milk, milk products and gluten may in many cases give reduced ADHD symptoms. Further, opioid peptides derived from food proteins (exorphins) have been found
in urine of autistic patients. This area of investigation is important and large scale, good quality randomised controlled trials are needed.