The authors declare that this work has been funded by the South African Medical Research Council (BHH). The funder has no other role in this study. The authors would like to thank Mr. Cor Bester, Me. Antoinette Fick and Mr. Petri Bronkhorst for their assistance in the breeding and welfare of the animals.

Conflict of interest

The authors declare that over the past 3 years. Brian Harvey has participated in speakers/advisory boards and received honoraria from Organon, Pfizer and Servier, and has received research funding from Lundbeck. The authors declare that, except for income from the primary employer and research funding to BHH from the South African Medical Research Council, and the above-mentioned exceptions, no financial support or compensation has been received from any individual or corporate entity over the past 3 years for research or professional services, and there are no personal financial holdings that could be perceived as constituting a potential conflict of interest. Michael Berk has received Grant/Research Support from the NIH, Cooperative Research Centre, Simons Autism Foundation, Cancer Council of Victoria, Stanley Medical Research Foundation, MBF, NHMRC, Beyond Blue, Rotary Health, Geelong Medical Research Foundation, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Organon, Novartis, Mayne Pharma and Servier, has been a speaker for Astra Zeneca, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Janssen Cilag, Lundbeck, Merck, Pfizer, Sanofi Synthelabo, Servier, Solvay and Wyeth, and served as a consultant to Astra Zeneca, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Janssen Cilag, Lundbeck Merck and Servier. Dr Berk is a co-inventor of two provisional patents regarding the use of NAC and related compounds for psychiatric indications, which, while assigned to the Flory Institute of Neuroscience and Mental Health, could lead to personal remuneration upon a commercialization event.