HTR5A and schizophrenia: This paper will review the evidence for attributing the risk of schizophrenia onset to early defects in serotonergic neurotransmission and explore the perspective of selective serotonin receptor inhibitor (SSRI) pharmacotherapy as a method of treatment and intervention for prodromal and ultra-high-risk patients by increasing 5-HT<sub>1A</sub> receptor sensitivity levels and modifying the transcription of 5-HT<sub>1A</sub> receptor-associated gene expression in these groups.