Provided are methods and compositions for treating autism spectrum disorders by administering an antioxidant or agent that stabilize or enhance expression of altered neuroligins. An aspect of the disclosure includes site-specific delivery of the antioxidant to the endoplasmic reticulum (ER) to reverse incorrect disulfide binding of the protein neuroligin. Also disclosed is a method of targeting the antioxidant to neuroligin by using the calcium binding or other recognition site of neuroligin to bind the antioxidant. The antioxidant can be cysteamine linked to a molecule which binds to a binding site.