Paranoid explanations of experience: a novel experimental study.

BACKGROUND: Paranoia is a common experience in the non-clinical population. We use a novel experimental methodology to investigate paranoid ideas in individuals without a history of mental illness. AIMS: We aimed to determine whether this paradigm could elicit unfounded paranoid thoughts and whether these thoughts could be predicted by factors from a cognitive model. METHOD: Fifty-eight individuals took part and completed measures assessing trait paranoia, mood, self and other schema and attributional style. They were exposed to two experimental events: 1) an interruption to the testing session by a stooge, and 2) a recording of laughter played outside the testing room and subsequently asked about their explanations for these events. RESULTS: 15.5% (n = 9) of the sample gave a paranoid explanation for at least one of the experimental events. The remainder reported generally neutral explanations. Individuals with a paranoid explanation reported significantly higher levels of trait paranoia. Factors predictive of a paranoid interpretation were interpersonal sensitivity and attributional style. CONCLUSIONS: The results show that spontaneous paranoid explanations can be elicited in non-clinical individuals, even for quite neutral events. In line with current theories, the findings suggest that emotional processes contribute to paranoid interpretations of events, although, as a novel study with a modest sample, it requires replication.

Spanish adaptation of the Green Paranoid Thought Scales.

BACKGROUND: The aim of this study was to adapt and obtain validity evidence of the Spanish Green Paranoid Thought Scales (S-GPTS). METHOD: 191 Spanish people responded to S-GPTS, Peters Delusions Inventory (PDI), and measures of psychopathology. RESULTS: Principal Component Analyses on the polychoric correlation matrix identified two factors accounting for 71.0% of the cumulative variance. Cronbach alphas for S-GPTS total and its subscales were above .90 in clinical and non-clinical group. The value of the area under the receiver operating characteristic curve was higher for the S-GPTS (.898), than for the PDI (.859). The best S-GPTS threshold to discriminate between cases and non-cases was 92 (sensitivity, 97.35%; specificity, 65%). S-GPTS scores positively correlated with PDI and measures of anxiety and depression. CONCLUSION: The S-GPTS has adequate psychometric properties to provide valid measures of delusional ideation in a Spanish population.