Examining the structure of ideas of reference in clinical and community samples.

AIMS: This study addresses the psychometric properties of a Spanish validation of the REF scale of ideas of reference (IRs) in detecting and following at-risk mental states and psychosis. METHODS: A total of 9447 participants were distributed in three groups: 676 patients with various diagnoses-154 with psychotic disorders, 6291 youths aged 11 to 20, and 2480 adult participants aged 21 to 84. RESULTS: Youths had higher scores than adults on IRs, observing a progressive decrease and stabilization in the twenties. Exploratory factor analysis provided a structure for the overall IRs score, with five first-order dimensions and one second-order dimension. Confirmatory factor analysis supported the structure with excellent fit. The REF scale was invariant across sex and samples. The internal consistency of the complete scale was excellent and acceptable across the five first-order factors. Strong relationships were found with the positive dimension of the community assessment of psychic experience-42, as well as with aberrant salience. Low and moderate relationships were found with public self-consciousness, anxiety, and depression. Youths and patients diagnosed with schizophrenia and other psychotic disorders had a high mean IRs frequency. Male sex, greater age (among the adults), and the "causal explanations", "Songs, newspapers, books" and "laughing and commenting" REF subscales showed predictive power in the diagnostic categories of schizophrenia and other psychotic disorders. CONCLUSIONS: The results provide satisfactory that the REF scale could be used to study psychosis.

Vulnerability to Psychosis, Ideas of Reference and Evaluation with an Implicit Test.

BACKGROUND: Ideas of reference (IRs) are observed in the general population on the continuum of the psychotic phenotype (as a type of psychotic-like experiences, PLE). The instruments usually used to evaluate IRs show some problems: They depend on the cooperation of the participant, comprehension of items, social desirability, etc. Aims: The Testal emotional counting Stroop (TECS) was developed for the purpose of improving evaluation of individuals vulnerable to psychosis and its relationship with ideas of reference. The TECS (two versions) was applied as an implicit evaluation instrument for IRs and related processes for early identification of persons vulnerable to psychosis and to test the possible influence of emotional symptomatology. METHOD: A total of 160 participants (67.5% women) from the general population were selected (Mean (M) = 24.12 years, standard deviation (SD) = 5.28), 48 vulnerable and 112 non-vulnerable. RESULTS: Vulnerability to psychosis was related to greater latency in response to referential stimuli. Version 4 of the TECS showed a slight advantage in identifying more latency in response to referential stimuli among participants with vulnerability to psychosis (Cohen's d = 1.08). Emotional symptomatology (especially stress), and IQ (premorbid) mediated the relationship between vulnerability and IR response latency. CONCLUSIONS: The application of the implicit Testal emotional counting Stroop test (TECS) is useful for evaluating processes related to vulnerability to psychosis, as demonstrated by the increased latency of response to referential stimuli.