Paranoia Rarely Begins As A Sudden Belief

It Often Starts As A Feeling That Something Has Changed

Psychiatry Has A Name For That Stage

Shitij Kapur Built A Model Around What Comes Before The Belief

His 2003 Paper Named It Aberrant Salience

The Claim Was That Neutral Things Feel Important First

Delusion Was Described As The Result Rather Than The Start

Twenty Years Of Testing Has Not Settled Whether That Is True

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Salience Names How Strongly A Stimulus Registers

Attention Shifts Toward Something Salient

Dopamine Is The Neurotransmitter Most Tied To That Process

Shitij Kapur Described It As Mediating Motivational Salience

That Framing Came From Work On Reward And Reinforcement

Stimuli Linked To Reward Acquire Value Through Repetition

That Language Can Make Dopamine Sound Deliberate

Dopamine Does Not Choose Anything Or Hold Any Intention

It Is A Chemical Whose Levels And Timing Can Be Measured

Much Of The Fine Grained Signaling Work Was Done In Animals

Those Findings Do Not Transfer To Humans Automatically

Human Evidence Comes Mostly From Imaging The Striatum

The Striatum Is A Structure Deep Inside The Brain

Researchers Divide It Into Three Functional Subdivisions

One Is Called Limbic And Another Associative

The Third Is Sensorimotor

Each Subdivision Connects To Different Cortical Regions

The Limbic Subdivision Is Tied To Reward Valuation

Associative Regions Relate To Goal Directed Learning

Sensorimotor Regions Correspond To Habitual Behavior

Where Dopamine Is Elevated Matters For Any Salience Claim

Kapur Placed The Fault In The Limbic Subdivision

That Location Became A Testable Prediction

Imaging Studies Have Since Measured That Directly

The 2003 Paper Ran In The American Journal Of Psychiatry

It Appears In Volume 160 At Pages 13 To 23

The Title Was Psychosis A State Of Aberrant Salience

Aberrant Salience Means Significance Assigned To Neutral Things

Kapur Traced That Misassignment To Excess Striatal Dopamine

He Then Made A Second And Less Obvious Move

Delusions Were Not Treated As The Primary Fault

They Were Framed As An Attempt To Explain The Experience

A Person Feels That Ordinary Details Have Become Significant

Kapur Called The Prelude To This A Delusional Mood

The Belief Forms Only After That State Begins

That Explanation Was Called Top Down And Cognitive

His Argument Was That The Person Imposes It On Experience

Paranoia Matches That Description Well

The Content Often Concerns Intent Directed At The Person

Explanation Then Registers As Insight Rather Than Invention

Certainty Follows Because The Experience Preceded The Idea

The Model Also Reached Into Drug Treatment

Dopamine Blocking Drugs Were Said To Reduce The Salience

Symptoms Would Then Resolve As That Salience Abates

Clinical Improvement Was The Evidence He Pointed To

Whether The Mechanism Works That Way Stayed Untested Then

A Review In 2025 Weighed Two Decades Of Evidence

Philip Corlett And Kurt Fraser Wrote It

The Same Journal Published It That September

It Appears In Volume 182 At Pages 819 To 829

Their Verdict Split Into Supported And Unsupported Claims

One Prediction Concerned Where Dopamine Is Elevated

Kapur's Model Named The Limbic Striatum

A 2018 Meta Analysis Tested Exactly That

It Pooled 21 Studies Covering 269 Patients And 313 Controls

Elevation Across The Whole Striatum Reached A Hedges g Of 0.68

The Associative Subdivision Came In At 0.73

Limbic Reached Only 0.29 And Missed Statistical Significance

That Is Not Where The Model Placed It

A Second Prediction Concerned Behavior On A Salience Task

Patients With Delusions Should Misassign More Than Controls

The Review Reports No Such Difference Between Those Groups

Earlier Work Had Found A Correlation Within Patient Groups

Those Two Results Have Not Been Reconciled

A Third Prediction Concerned People At High Risk

Differences There Failed To Predict Later Psychosis

Corlett And Fraser Argue The Strong Salience Claim Is Unsupported

Newer Work Studies Dopamine In Belief Updating Under Uncertainty

One 2020 Study Linked Paranoia To Expecting Frequent Change

Its Rat Results Are An Animal Model Rather Than Human Proof