PTI

Aliases

• PTI
• Perceptual-Thinking Index
• perceptual-thinking index

Definition

PTI is a composite index that groups signs of perceptual and thinking disorganization. Its function is to alert the reader to review possible distortion of reality, ideational slippage, or loss of perceptual precision.

Interpretation

• If PTI is positive, mediation and ideation should be reviewed first.
• The index usually becomes more meaningful when problems converge in WSum6, Lv2, M-, X-%, and XA%.
• Its interpretation points to possible thought disturbance, not an automatic diagnosis.
• The index gains weight when several different parts of the protocol point in the same direction.

Cautions

• A positive PTI does not by itself mean psychosis.
• A negative PTI does not remove all possibility of disturbed thinking.
• Extreme stress, intoxication, situational disorganization, or very low response volume can complicate the reading.

Cautions

• PTI is an actuarial signal and requires returning to the base variables.
• WSum6, Lv2, M-, X-%, and XA% should be reviewed before drawing strong conclusions.

Variables to Review Together

• WSum6
• Lv2
• M_minus
• X_minus_percent
• XA_percent

Cross References

• [Interpretation/Special Indices] Special Indices
• [Interpretation/Ideation] WSum6
• [Interpretation/Ideation] Lv2
• [Interpretation/Ideation] M-
• [Interpretation/Mediation] X-%
• [Interpretation/Mediation] XA%

Evidence Strength

• Evidence tier: supported
• Empirical support is relatively strong among the special indices, but PTI cannot independently diagnose a thought disorder or psychotic disorder.
• Review the actual WSum6, Lv2, M-, X-%, and XA% pattern and consider acute stress, intoxication, developmental factors, and short records instead of relying on the positive/negative label alone.