Mapping the genetic landscape across 14 psychiatric disorders

Area of Science:

• Psychiatric Genetics
• Genomics
• Neuroscience

Background:

• Psychiatric disorders exhibit significant comorbidity and genetic overlap, challenging traditional diagnostic classifications.
• Previous genomic studies identified shared genetic signals but failed to fully define disorder-specific influences.
• Understanding shared genetic architecture is crucial for refining psychiatric nosology and developing targeted therapies.

Purpose of the Study:

• To comprehensively characterize shared and disorder-specific genetic influences across 14 psychiatric disorders.
• To identify underlying genomic factors contributing to the genetic variance of these disorders.
• To explore the neurobiological underpinnings of shared genetic factors for therapeutic implications.

Main Methods:

• Applied advanced statistical and functional genomic analyses to a large dataset of 1,056,201 cases across 14 psychiatric disorders.
• Utilized common variant genetic association data to identify and characterize underlying genomic factors.
• Investigated polygenic overlap, local genetic correlation, and pathway enrichment for identified genomic factors.

Main Results:

• Identified five genomic factors explaining approximately 66% of the genetic variance across the 14 disorders, linked to 238 pleiotropic loci.
• Found substantial genetic overlap between schizophrenia and bipolar disorder (SB factor), and major depression, PTSD, and anxiety (Internalizing factor), with few disorder-specific loci.
• Discovered distinct biological enrichments: SB factor associated with excitatory neuron genes, Internalizing factor with oligodendrocyte biology.

Conclusions:

• The majority of genetic variance in psychiatric disorders is explained by shared genomic factors, not disorder-specific influences.
• Findings support a potential shift towards a more neurobiologically informed psychiatric nosology.
• Identified shared genetic pathways offer novel targets for developing therapeutics for common comorbid psychiatric conditions.