Effects of open access publishing on article metrics in Neuropsychopharmacology.

Neuropsychopharmacology (NPP) offers the option to publish articles in different tiers of an open access (OA) publishing system: Green, Bronze, or Hybrid. Green articles follow a standard access (SA) subscription model, in which readers must pay a subscription fee to access article content on the publisher's website. Bronze articles are selected at the publisher's discretion and offer free availability to readers at the same article processing charge (APC) as Green articles. Hybrid articles are fully OA, but authors pay an increased APC to ensure public access. Here, we aimed to determine whether publishing tier affect the impact and reach of scientific articles in NPP. A sample of 6000 articles published between 2001-2021 were chosen for the analysis. Articles were separated by article type and publication year. Citation counts and Altmetric scores were compared between the three tiers. Bronze articles received significantly more citations than Green and Hybrid articles overall. However, when analyzed by year, Bronze and Hybrid articles received comparable citation counts within the past decade. Altmetric scores were comparable between all tiers, although this effect varied by year. Our findings indicate that free availability of article content on the publisher's website is associated with an increase in citations of NPP articles but may only provide a moderate boost in Altmetric score. Overall, our results suggest that easily accessible article content is most often cited by readers, but that the higher APCs of Hybrid tier publishing may not guarantee increased scholarly or social impact.