<i>HTR5A-AS1</i> was strongly co-expressed with <i>HTR5A</i>, and functional predictions implicated involvement in synaptic and GABAergic signaling, consistent with cortico-hippocampal circuit disruption in schizophrenia.<h4>Conclusions</h4>These findings provide the first evidence that <i>HTR5A-AS1</i> is a bona fide antisense transcript with developmental and synaptic roles that may contribute to schizophrenia risk. This evidence concerns the gene HTR5A and schizophrenia.