# Molecular Basis Underlying Changes of Brain Entropy and Couplings in Late-life Depression. > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/molecular-basis-underlying-changes-of-brain-entropy-and-couplings-in-late-l/ > **Published:** 2026-04-28T14:03:48-04:00 | **Last Modified / Clinically Audited:** 2026-09-28T16:04:18-04:00 > **Clinical Summary:** Late-life depression (LLD) with high prevalence accelerates cognitive impairment and becomes a risk factor for dementia, yet the pathogenesis of LLD is still... --- CED Clinical Relevance  #58Monitored Relevance  Early-stage or contextual signal requiring further evidence before action. 🔬 Evidence Watch  |  CED Clinic Journal Current neuropharmacology Study Type [Clinical Study](https://cedclinic.com/cannabis-hyperemesis-syndrome-psychiatric-risk/) Population Human participants Why This Matters This item covers developments relevant to [cannabis medicine](https://cedclinic.com/essential-oils-industrial-hemp-antimicrobial-benefits/) and [clinical practice](https://cedclinic.com/cannabis-reproductive-health-women-clinical-evidence/). Clinicians monitoring evidence in this area should review the source material. [Clinical Summary](https://cedclinic.com/recreational-marijuana-legalization-24-states-update/) Late-life depression (LLD) with high prevalence accelerates [cognitive impairment](https://cedclinic.com/acute-effects-partial-cb1-receptor-agonists-cognition/) and becomes a risk factor for dementia, yet the pathogenesis of LLD is still largely unclear. Delineating the neuromolecular mechanism of LLD is of great significance to its etiology, early diagnosis, and precision treatment. This study included 35 patients with LLD and 41 age-matched healthy controls (HCs). Brain entropy (BEN) and functional connectivity (FC) were used to assess the abnormalities in brain functional system irregularity and couplings in LLD, using resting-state functional magnetic resonance imaging. Additionally, transcriptome and neurotransmitter data were employed to investigate the neuromolecular mechanisms underlying these changes. Compared with HCs, patients with LLD exhibited significantly reduced BEN in the temporoparietal junction (TPJ) and decreased FC between TPJ and the middle frontal gyrus (MFG). Moreover, the changes of BEN were closely associated with the genes’ expression pr Dr. Caplan’s Take “This is a development worth tracking. The clinical implications will become clearer as more evidence accumulates.” Clinical Perspective 🧠 Clinicians should review this item in the context of their current practice and patient population. 💬 Join the Conversation Have a question about how this applies to your situation? [Ask Dr. Caplan →](https://benjamincaplan.com/ask-dr-caplan) Want to discuss this topic with other patients and caregivers? [Join the forum discussion →](https://cedclinic.com/interact/discussion-forums/forum/cannabis-industry/) Have thoughts on this? Share it: [X Share on X](https://twitter.com/intent/tweet?text=Just%20read%20this%20on%20CEDclinic.com%3A%20Molecular%20Basis%20Underlying%20Changes%20of%20Brain%20Entropy%20and%20Couplings%20in%20Late-life%20Depression.%20%40drcaplan&url=https%3A%2F%2Fcedclinic.com%2Fmolecular-basis-underlying-changes-of-brain-entropy-and-couplings-in-late-l%2F)[in Share on LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fcedclinic.com%2Fmolecular-basis-underlying-changes-of-brain-entropy-and-couplings-in-late-l%2F)[🦅 Share on BlueSky](https://bsky.app/intent/compose?text=Just%20read%20this%3A%20Molecular%20Basis%20Underlying%20Changes%20of%20Brain%20Entropy%20and%20Couplings%20in%20Late-life%20Depression.%20via%20%40drcaplan.bsky.social%20https%3A%2F%2Fcedclinic.com%2Fmolecular-basis-underlying-changes-of-brain-entropy-and-couplings-in-late-l%2F)[📷 Follow on Instagram](https://www.instagram.com/drbenjamincaplan)[📝 Read more on Substack](https://doctorapprovedcannabis.substack.com/)[🔔 Subscribe via RSS](https://cedclinic.com/feed/) 📰 Source: [https://pubmed.ncbi.nlm.nih.gov/42003122/](https://pubmed.ncbi.nlm.nih.gov/42003122/) Table of Contents - [FAQ](#FAQ)[Why is late-life depression an important focus for research?](#Why_is_late-life_depression_an_important_focus_for_research) - [How did the researchers study the brain in late-life depression?](#How_did_the_researchers_study_the_brain_in_late-life_depression) - [What brain differences were found in people with late-life depression?](#What_brain_differences_were_found_in_people_with_late-life_depression) - [Related](#Related) ## FAQ ### Why is late-life depression an important focus for research? Late-life depression is highly prevalent, accelerates [cognitive impairment](https://cedclinic.com/acute-effects-partial-cb1-receptor-agonists-cognition/), and is a risk factor for dementia, yet its causes remain largely unclear. The article states that clarifying its neuromolecular mechanism is of great significance for understanding its origins, diagnosing it early, and developing precision treatment. ### How did the researchers study the brain in late-life depression? The study compared 35 patients with late-life depression with 41 age-matched healthy controls using resting-state functional MRI. Brain entropy was used to assess irregularity in brain functional systems, and functional connectivity was used to assess couplings. Transcriptome and neurotransmitter data were then used to explore the molecular mechanisms behind these changes. ### What brain differences were found in people with late-life depression? Compared with healthy controls, patients with late-life depression showed significantly reduced brain entropy in the temporoparietal junction (TPJ). They also had decreased functional connectivity between the temporoparietal junction and the middle frontal gyrus (MFG), indicating weaker coupling between these two brain areas. [https://cedclinic.com/contact/](https://cedclinic.com/contact/) Physician-Led, Whole-Person Care A doctor who takes the time to truly understand you. Personal care that starts with listening and is guided by experience and ingenuity. Health, Longevity, Wellness One-on-One Cannabis Guidance Metabolic Balance [Leave a Message](https://cedclinic.com/contact/) [Metabolic Care](https://cedclinic.com/metabolic/metabolic-how-it-works/) [Medical Consulting](https://cedclinic.com/book/) [Cannabis Care](https://cedclinic.com/book/) [https://cedclinic.com/contact/](https://cedclinic.com/contact/) ### Related --- ### Verification & Medical Governance - **Lead Clinical Author:** Benjamin Caplan, MD - **Credentials:** Board Certified in Family Medicine (ABFM), Former CMO Canna Care Docs (250,000+ patients supervised), Founder & CMO CED Clinic & CED Foundation, Author of *The Doctor-Approved Cannabis Handbook* (Penguin Random House). - **Clinical Scale:** 350,000+ lifetime evaluations overseen; 81,008-patient Real-World Evidence Registry (`~/.ced_rwe_vault.db`); 125,000+ peer-reviewed study literature observatory (`http://localhost:8768/api/explorer/terminal`). - **License Verification:** Commonwealth of Massachusetts License #240562 (https://checkahealthlicense.mass.gov/). - **NPI Registry:** 1962722637 (https://npiregistry.cms.hhs.gov/provider-view/1962722637). - **Ethics & Data Privacy:** Clinical registry observations adhere strictly to HIPAA Safe Harbor de-identification (45 CFR § 164.514(b)) and criteria for secondary research exemption under 45 CFR § 46.104(d)(4).