Similarities and dissimilarities between psychiatric cluster disorders

Area of Science:

• Neuroscience
• Genetics
• Pharmacology

Background:

• The molecular underpinnings of psychiatric disorders remain largely unknown.
• Previous studies faced limitations due to biased disorder selection, data availability, and normalization challenges.

Purpose of the Study:

• To comprehensively investigate common molecular mechanisms across a broad spectrum of psychiatric disorders.
• To identify shared and distinct pathological features and potential therapeutic targets using an unbiased approach.

Main Methods:

• Utilized DisGeNET, a gene-disease association database, to analyze 36 psychiatric disorders and comorbid conditions.
• Employed a novel 'density index' metric to quantify similarities and dissimilarities at pathway, cell-type, drug-target, and chromosome levels.
• Performed a multi-level analysis including biological pathways, cell types, drug targets, and chromosomal associations.

Main Results:

• Cognition and neurotransmission pathways drive similarity across all analyzed disorders.
• Immune system and signal-response pathways contribute to disorder-specific dissimilarities.
• Neurotransmission-related drug targets are implicated across disorders, with dendrite-targeting interneurons being notably involved at the cellular level.
• Chromosomal level interactions most significantly influence disorder similarity, followed by cellular level influences.

Conclusions:

• Identified distinct cellular and molecular pathologies and druggable mechanisms common to several psychiatric disorders.
• Demonstrated that psychiatric disorder similarities originate at the chromosomal level and propagate upwards to cellular and pathway levels.
• Provided novel insights into the complex molecular architecture underlying psychiatric conditions.