The Insulin-like Growth Factor Family as a Potential Peripheral Biomarker in Psychiatric Disorders: A Systematic...

Area of Science:

• Neuroscience
• Biochemistry
• Psychiatry

Background:

• Psychiatric disorders (PDs) pose a significant global health burden, with diagnoses relying on subjective assessments due to a lack of objective biomarkers.
• Peripheral biomarkers, such as those in plasma or serum, offer accessible and cost-effective insights into central nervous system processes.
• The insulin-like growth factor (IGF) family, including IGF-1, IGF-2, and IGF-binding proteins (IGFBPs), plays crucial roles in neuroplasticity, cognition, and neuroprotection.

Purpose of the Study:

• To review and evaluate the evidence for alterations in the IGF family across various psychiatric disorders over the past 40 years.
• To focus specifically on the roles of IGFs in schizophrenia (SZ), major depressive disorder (MDD), and bipolar disorder (BD).
• To assess the potential of IGFs as reliable peripheral biomarkers for psychiatric conditions.

Main Methods:

• Comprehensive literature review spanning approximately 40 years of research.
• Analysis of studies investigating IGF-1, IGF-2, and IGFBP levels in patients with schizophrenia, major depressive disorder, bipolar disorder, and other psychiatric disorders.
• Evaluation of the association between IGF alterations and clinical features, including metabolic dysregulation and neurogenesis.

Main Results:

• In schizophrenia, IGF-1 alterations are linked to metabolic issues, treatment response, and HPA axis dysfunction.
• In major depressive disorder, IGF-1 may play a compensatory role in neurogenesis, though findings are inconsistent.
• Emerging evidence suggests potential roles for IGF-2 and IGFBPs across a spectrum of psychiatric disorders.

Conclusions:

• The IGF family shows promise as potential peripheral biomarkers for psychiatric disorders.
• Heterogeneity in study findings and methodological limitations necessitate further rigorous research.
• Validation of IGFs as reliable biomarkers for psychiatric conditions requires more consistent and robust evidence.