The Loot Drop
Research reviews for neurodivergent families
Issue #6 • January 29, 2026
Correlation Isn't Causation (And Why That Matters for Your Family)
The biggest psychiatric genetics study ever made headlines everywhere. Most of them got it wrong.
📢 WHY WE'RE WRITING THIS
If you saw this headline and felt a pit in your stomach, you're not alone. A massive genetic study published in Nature made headlines across Fox News, Yahoo, and social media with one big problem. The headlines say "genetic cause." The study measured genetic correlation. That's not the same thing, and we're going to break down what it actually means for your family.
⚡ TL;DR
The study found that 14 psychiatric conditions share patterns of genetic correlation — not causation. The methods used literally cannot prove genes cause these disorders. The media got this wrong. The study is still useful for understanding why conditions cluster together, but it doesn't change what you should do as a parent.
Legendary
Epic
Rare
Common
The Headline Problem
WHAT THE HEADLINES SAID
"Depression, anxiety and other disorders may have the same genetic cause"
— Fox News, Yahoo News (January 2026)
WHAT THE STUDY ACTUALLY FOUND
"14 psychiatric disorders show genetic correlation patterns that cluster into 5 groups"
Why does this matter?
Correlation means two things tend to appear together. Causation means one thing makes the other happen. The methods this study used — LDSC, Genomic SEM, MiXeR — are explicitly designed to measure correlation, not causation. The study authors know this. The journalists apparently didn't.
What the Study Actually Found
FINDING 01
Five genetic "clusters" across 14 disorders
Analyzing DNA from over 1 million people with psychiatric conditions, researchers found that genetic variants associated with these disorders tend to cluster into five groups: Compulsive (anorexia, OCD, Tourette's), Schizophrenia-Bipolar, Neurodevelopmental (autism, ADHD), Internalizing (depression, anxiety, PTSD), and Substance Use.
FINDING 02
~66% of genetic variance is shared
On average, about two-thirds of the genetic signal for any single disorder was captured by these five shared factors. This suggests these conditions aren't as genetically distinct as our diagnostic categories imply. Schizophrenia and bipolar disorder, for example, share roughly 70% of their genetic signal.
FINDING 03
Different brain cell types implicated for different clusters
The schizophrenia-bipolar cluster showed enrichment in excitatory neurons (cells that transmit "go" signals). The internalizing cluster (depression, anxiety) showed enrichment in oligodendrocytes, support cells that help signals travel faster. This points to potentially different biological pathways.
FINDING 04
238 genetic "hot spots" identified
The study pinpointed 238 specific locations in the genome associated with multiple disorders, including a cluster on Chromosome 11 affecting eight different conditions. One gene there, DRD2, regulates dopamine and is the primary target of antipsychotic medications.
Why It Matters
This validates what many families already experience
If your child has ADHD and anxiety, or autism and depression, this study helps explain why conditions so often travel together. It's not bad luck or misdiagnosis. There's genuine biological overlap. This doesn't mean something is "wrong" — it means your child's brain is wired in a way that crosses the arbitrary lines we've drawn between diagnostic categories. A study of nearly 6 million people confirmed what parents already know: if you have one neurodevelopmental or mental health condition, others often come along, with some combinations appearing together up to 48 times more often than in the general population.
It supports comprehensive evaluation
This study reinforces that when evaluating a child for one condition, clinicians should screen broadly. The genetic architecture suggests looking at the whole picture rather than treating conditions as isolated silos.
The Fine Print
This is an exceptionally well-conducted study. That's why we rated Rigor as Legendary. But the media coverage has critical problems, and even the study itself has important limitations that families should understand.
📰 MEDIA FAILURE
The headline says "cause" — the methods measure correlation
The study used LDSC (Linkage Disequilibrium Score Regression) and Genomic SEM, methods explicitly designed to measure genetic correlation, not causation. The original LDSC methodology paper states that genetic correlations "could result from a causal effect" but "could also be mediated" by other factors — correlation helps "prioritize likely causal relationships" but doesn't establish them. Journalists using "cause" in headlines misrepresent what the study can actually claim.
🚨 CRITICAL GAP
Assortative mating may inflate correlations
A 2022 study in Science by Border et al. found that cross-mate similarities predict 74% of the variance in genetic correlation estimates across traits. Translation: the tendency for people with one trait to partner with people who have related traits ("cross-trait assortative mating") may substantially inflate reported genetic correlations — potentially without any shared biological mechanism. The Nature study authors acknowledge this limitation.
⚠️ NOTABLE
No Mendelian randomization = no causal proof
The gold standard for establishing causation in genetics is Mendelian randomization — which uses genetic variants as "natural experiments" to test causal relationships. This study didn't include it. Until we see MR studies, we cannot say these genes cause these disorders.
Our take: This is a rigorous, well-conducted study that provides a useful map of genetic overlap patterns. But correlation is not causation — and the headlines got this critically wrong. The study can't tell us that genes cause these disorders to co-occur, only that they tend to show up together statistically. For families, this validates seeking comprehensive evaluations but doesn't change what you should actually do.
🚨 BE SKEPTICAL WHEN YOU SEE
• Headlines claiming genes "cause" psychiatric disorders based on correlation studies
• Claims that genetic testing can diagnose or predict mental health conditions
• Suggestions that comorbidity is "just genetic" (environment still matters enormously)
• Marketing for expensive genetic tests or brain scans based on this research
• Claims that genetic testing can diagnose or predict mental health conditions
• Suggestions that comorbidity is "just genetic" (environment still matters enormously)
• Marketing for expensive genetic tests or brain scans based on this research
✅ WHAT'S STILL TRUE
• Psychiatric conditions do tend to cluster in families and individuals
• Comprehensive evaluation for multiple conditions makes sense
• Your child's combination of conditions isn't random or your fault
• There's no single "autism gene" or "ADHD gene" — these are patterns across thousands of tiny effects
• Environment, stress, and lifestyle still matter — genes aren't destiny
• Comprehensive evaluation for multiple conditions makes sense
• Your child's combination of conditions isn't random or your fault
• There's no single "autism gene" or "ADHD gene" — these are patterns across thousands of tiny effects
• Environment, stress, and lifestyle still matter — genes aren't destiny
What to Do With This
👨👩👧 FOR PARENTS
Don't panic about genetics. This study doesn't mean your child's conditions are "hardwired" or that nothing can help. It means when seeking evaluation, ask clinicians to screen broadly — if your child has ADHD, screening for anxiety makes sense. If they have autism, watch for depression. The clustering is real, but so is the ability to address each condition.
🧑🤝🧑 FOR ADULTS WITH MULTIPLE DIAGNOSES
Your experience is validated. If you've been told you have "too many diagnoses" or that your conditions must be "really just one thing," this study shows the overlap is biologically real. Multiple diagnoses aren't overdiagnosis — they reflect genuine patterns in how these conditions relate.
🩺 FOR CLINICIANS
Screen across cluster boundaries. The five-factor structure suggests screening protocols that cross traditional diagnostic silos. A patient presenting with OCD might benefit from screening for anorexia and anxiety (compulsive cluster), while someone with schizophrenia warrants close monitoring for bipolar features.
🔬 FOR THE CURIOUS
Learn to spot correlation vs. causation in headlines. When you see "genes for X" or "genetic cause of Y," ask: What methods did they use? Did they do Mendelian randomization? Is this GWAS (correlation) being dressed up as causation? This skill will serve you well beyond psychiatric genetics.
🏆 THE BOTTOM LINE
This is a landmark study that mapped genetic correlation patterns across 14 psychiatric disorders — but correlation isn't causation, and the headlines got it wrong. The research validates what families already know: these conditions travel together. It doesn't prove genetics causes that clustering, and it doesn't change what you should do. Keep advocating for comprehensive evaluation, supporting your child's specific needs, and remember that genes aren't destiny.