Did You Know That A Shared Delusion Can Spread Over The Phone?

A Team In Spain Reported One Such Case Between Two Sisters

They Said It Raises Questions About Influence From Far Away

Researchers Now Say Chatbot Conversations Can Carry A Similar Risk

THIS NEWSLETTER IS FOR INFORMATIONAL PURPOSES ONLY. NOTHING IN THIS CONTENT CONSTITUTES MEDICAL, PSYCHOLOGICAL, OR PROFESSIONAL ADVICE. ALWAYS CONSULT A QUALIFIED HEALTHCARE PROFESSIONAL BEFORE MAKING ANY HEALTH RELATED DECISIONS.

OKAY BACK FROM THE PHONE BOOTH ☎️

A Farmer Aged 60 Lived In An Isolated Village In Northeastern India

His Wife Was 50 And Their Son Was 22

The Couple Had Been Married For More Than Three Decades

Their Nearest Neighbors Lived Half A Mile Away

Most Of The Time The Family Stayed Indoors

Their Use Of A Mobile Phone Was Limited

Three Months Before The Hospital Visit His Wife Rubbed Her Sore Elbow

The Farmer Said He Saw Tiny White Insects Coming Out Of Her Skin

At First She Felt Nothing Unusual

He Kept Checking Her Elbow And Collecting Skin Flakes As Samples

Within A Week She Said She Saw White Specks Too

Later She Felt Something Crawling On That Same Elbow

Two Weeks After That Their Son Reported The Same Thing

He Avoided Touching His Mother's Elbow And Sat Apart At Meals

By The Fourth Week All Three Were Cleaning The Elbow With Kerosene

The Farmer Burned Three Sets Of Bedclothes

A Health Worker And A Doctor Found No Sign Of Infestation

Even So The Family Stayed Convinced

The Family Went To A Hospital Skin Clinic And Was Sent To Psychiatry

All Three Were Put On The Same Antipsychotic Drug

The Farmer Was Told To Keep His Distance From His Wife And Son

Within Four Weeks Their Symptoms Had Dropped Sharply

The Psychiatrists Believed Closeness And Isolation Played A Part

A 59 Year Old Woman In Spain Was Hospitalized With A Shared Delusion

Her Sister Had Developed Persecutory Delusions First

Those Delusions Were Tied To A Complicated Divorce

The Two Sisters Stayed Close Through Frequent Phone Calls

Over Five Years The Woman Came To Share The Same Delusions

Both Believed They Were Being Persecuted And Watched

According To Her Doctors The Delusions Developed Mainly Through Calls

In July 2024 Her Sister Came To Visit Her In Madrid

After That Visit Her Symptoms Got Much Worse

She Was Admitted To A Short Stay Psychiatric Unit

Doctors There Started Her On Antipsychotic And Antidepressant Drugs

The Antipsychotic Drug Worked And Her Active Symptoms Went Away

She Came To See Her Delusions As Her Sister's Influence

Since Leaving Hospital She Has Stayed Stable

Her Doctors Concluded Phone Calls Alone Can Pass On A Shared Delusion

They Suggested That Closeness Affects How Severe It Becomes

That Closeness Can Be Physical Or Emotional

Even Contact From A Distance Can Keep A Delusion Going

A 2026 Paper Was Titled Technological Folie A Deux

It Appeared In The Journal Nature Mental Health

Millions Of People Now Use Chatbots For Emotional Support

The Paper Described A Loop Between A User And A Chatbot

Chatbots Tend To Agree With Users And Confirm Their Views

That Agreement Can Make A User's Belief Stronger

The Stronger Belief Then Goes Back Into The Conversation

That Changes What The Chatbot Says Next

In The Extreme The Authors Said This Resembles A Folie A Deux

To Test The Idea They Ran 300 Simulated Conversations

Two Copies Of One Chatbot Model Played The User And The Chatbot

Those Users Were Given Different Levels Of Paranoia

Each Conversation Opened With A Worker Left Out Of A Team Lunch

User Paranoia Raised The Paranoia In The Chatbot's Replies

It Worked In The Other Direction As Well

The Authors Noted The Study Used Simulated Users And Not Real People

People With Mental Health Conditions May Face A Higher Risk

The Risk May Be Greater When Those Conditions Involve Isolation