|Dude means a regular sort of person...|
So said one of the conclusions of the paper by Jessica Jackson and colleagues  as the results further stack up implicating immune function and diet in relation to at least some cases of schizophrenia. That being said, researchers did not find any "robust clinical profile" which differentiated those with antibodies from those without on the basis of symptom presentation, so it seems the only way to determine possible gluten sensitivity is to do some blood work.
I'd only be repeating myself (see here) if I went on discussing the Jackson results in any great detail. That such findings, alongside quite a lot more focus on the gut-brain axis (see here and see here) in relation to at least some schizophrenia (the schizophrenias?) are becoming all too frequent these days in the peer-reviewed research literature is deserving of some real action now. Indeed, a recent Nature piece said as much with the title: Gut–brain link grabs neuroscientists (perhaps only missing out on what exactly has been grabbed).
This authorship group have previously described preliminary results based on the use of a gluten-free diet in cases of schizophrenia  (open-access) but a large comprehensive trial is still lacking at the time of writing. Indeed one has to go back to 1986 and the days of Billy Ocean talking about The Tough Gettin' Going and the results published by Vlissides and colleagues  to see how long such a trial has been awaited (assuming we don't count the even earlier writings of the late Curt Dohan on this topic).
Oh and that a gluten-free diet might not be the only research direction to take is another potentially important point...
 Jackson J. et al. Gluten sensitivity and relationship to psychiatric symptoms in people with schizophrenia. Schizophrenia Research. 2014. 11 October.
 Jackson J. et al. A gluten-free diet in people with schizophrenia and anti-tissue transglutaminase or anti-gliadin antibodies. Schizophr Res. 2012 Sep;140(1-3):262-3.
 Vlissides DN. et al. A double-blind gluten-free/gluten-load controlled trial in a secure ward population. Br J Psychiatry. 1986 Apr;148:447-52.
Jackson J, Eaton W, Cascella N, Fasano A, Santora D, Sullivan K, Feldman S, Raley H, McMahon RP, Carpenter WT Jr, Demyanovich H, & Kelly DL (2014). Gluten sensitivity and relationship to psychiatric symptoms in people with schizophrenia. Schizophrenia research PMID: 25311778