Since the publication of the first meta-analysis, olfactory research in schizophrenia has grown exponentially, with over 100 studies published since that time. This exponential growth has coincided with a greater refinement in reporting medication and smoking variables. For example, the calculation of pack years and pack days as measures of smoking dosages have now been reported across several studies. In addition, new meta-analytic techniques have emerged that enable the examination of moderator variables such as duration of illness, age of illness onset, and antipsychotic medication type. The growing body of olfactory studies in first-degree family members, youths at-risk for psychosis, and individuals with psychometrically defined schizotypy has also allowed for the analysis of study effect sizes in these subgroups. Finally, research on olfactory hedonic judgments has also gained interest in schizophrenia, with studies examining qualitative ratings of odor characteristics.