Comparisons between self-reported and interview-verified psychotic-like experiences in adolescents

Area of Science:

• Psychiatry
• Psychological Assessment
• Mental Health Research

Background:

• The Community Assessment of Psychic Experiences (CAPE-P15) is frequently used to measure self-reported psychotic-like experiences (PLEs).
• The established validity of the CAPE-P15, particularly its positive subscale, requires further investigation.
• There is a need to assess the consistency between self-reported and interview-verified PLEs.

Purpose of the Study:

• To evaluate the consistency between self-reported PLEs (PLEs-S) and interview-verified PLEs (PLEs-I) using the CAPE-P15.
• To determine the validity of the CAPE-P15 in a college student population.
• To explore the diagnostic accuracy of specific CAPE-P15 items, especially concerning associated distress.

Main Methods:

• 1255 college students completed the CAPE-P15 to assess lifetime and current PLEs.
• Telephone interviews were conducted with high-risk students and a subset of others, using CAPE-P15 items and criteria for attenuated positive symptom syndrome.
• Analysis focused on correspondence rates (CRs) and kappa (κ) values to assess consistency.

Main Results:

• When considering PLEs alone, consistency between self-report and interview was below established thresholds (low κ values and CRs).
• Adequate consistency (κ = .432, CR = 90.0%) was found for lifetime PLEs when associated distress was included in self-reports.
• Bizarre experiences (BEs) demonstrated adequate diagnostic accuracy for lifetime PLEs when distress was considered. Optimal cut-off points for frequency scores were identified for lifetime and past-month PLEs.

Conclusions:

• The overall validity of the CAPE-P15 for genuine PLEs is limited, but its accuracy improves significantly when associated distress is considered.
• The scale is particularly effective for detecting lifetime PLEs when distress is factored in.
• Self-report items related to bizarre experiences may be valuable for identifying PLEs in late adolescence.