Passage
Psychotic disorders are characterized by a loss of contact with reality. The most common psychotic disorder is schizophrenia, which has a typical onset of psychotic symptoms in early adulthood. Schizophrenia displays considerable inter-individual variation throughout the course of the disorder; many factors appear to influence its progression. Comorbid (co-occurring) conditions, common in schizophrenia, may lead to poorer prognoses. For example, research suggests that fewer depressive symptoms are moderately associated with higher rates of medication compliance, whereas more depressive symptoms are associated with increased future relapses. The early detection of psychosis also appears to have a significant impact on long-term outcomes in schizophrenia. A first psychotic episode that goes untreated for a longer period is associated with more future hospitalizations and a diminished response to future therapeutic interventions.Researchers conducted a study to determine which was better at predicting the development of psychosis, a major component of schizophrenia, in high-risk young adults: the presence of certain speech pattern features or a standard clinical symptom inventory. The participant sample was restricted to 50 younger adults (age 18-30) who either met criteria for prodromal syndrome (preclinical signs of psychosis) or had a first-degree relative with schizophrenia.Every three months for three years, participants were interviewed and given the Symptoms of Psychosis Inventory (SPI) , a standardized clinical assessment designed to measure psychosis and related symptoms. The SPI contains two subscales based on the major symptoms of schizophrenia: the Positive Symptom Scale (PSS) and the Negative Symptom Scale (NSS) , which are summed to provide a total SPI score. Transcribed interview data were analyzed with software designed to assess the following speech pattern features: semantic coherence (the relatedness of phrases to one another) , the number of determiners (eg, "that," "which," "what") used in a phrase (determiner density) , and phrase length.Experienced clinicians diagnosed 11 participants with active psychosis by the end of the study. A computer program generated two models that predicted the development of active psychosis based on the data collected. One model based the prediction solely on a combination of the three speech pattern features ("Speech Model") and the other model based the prediction solely on SPI symptoms data ("SPI Model") (Table 1) .Table 1 Comparison of Predictive Models

-Which of the following is accurate regarding the design of the study described in the passage?

Question

Passage
Psychotic disorders are characterized by a loss of contact with reality. The most common psychotic disorder is schizophrenia, which has a typical onset of psychotic symptoms in early adulthood. Schizophrenia displays considerable inter-individual variation throughout the course of the disorder; many factors appear to influence its progression. Comorbid (co-occurring) conditions, common in schizophrenia, may lead to poorer prognoses. For example, research suggests that fewer depressive symptoms are moderately associated with higher rates of medication compliance, whereas more depressive symptoms are associated with increased future relapses. The early detection of psychosis also appears to have a significant impact on long-term outcomes in schizophrenia. A first psychotic episode that goes untreated for a longer period is associated with more future hospitalizations and a diminished response to future therapeutic interventions.Researchers conducted a study to determine which was better at predicting the development of psychosis, a major component of schizophrenia, in high-risk young adults: the presence of certain speech pattern features or a standard clinical symptom inventory. The participant sample was restricted to 50 younger adults (age 18-30) who either met criteria for prodromal syndrome (preclinical signs of psychosis) or had a first-degree relative with schizophrenia.Every three months for three years, participants were interviewed and given the Symptoms of Psychosis Inventory (SPI) , a standardized clinical assessment designed to measure psychosis and related symptoms. The SPI contains two subscales based on the major symptoms of schizophrenia: the Positive Symptom Scale (PSS) and the Negative Symptom Scale (NSS) , which are summed to provide a total SPI score. Transcribed interview data were analyzed with software designed to assess the following speech pattern features: semantic coherence (the relatedness of phrases to one another) , the number of determiners (eg, "that," "which," "what") used in a phrase (determiner density) , and phrase length.Experienced clinicians diagnosed 11 participants with active psychosis by the end of the study. A computer program generated two models that predicted the development of active psychosis based on the data collected. One model based the prediction solely on a combination of the three speech pattern features ("Speech Model") and the other model based the prediction solely on SPI symptoms data ("SPI Model") (Table 1) .Table 1 Comparison of Predictive Models

-Which of the following is accurate regarding the design of the study described in the passage?

Quizplus · Accepted Answer

11ecba2d_0da6_e9f3_a3bf_4bf5731eec8d_MD0008_00 A scientific hypothesis is a testable explanation for a phenomenon. The alternative hypothesis is based on prior evidence and assumes that a significant relationship or difference exists between variables (and often predicts the nature of that relationship or difference). In this study, the alternative hypothesis was that a significant difference would be found between statistical models of speech pattern features and clinical symptom assessments in the accuracy of psychosis prediction. The inverse of the alternative hypothesis, the null hypothesis, states that there is no significant difference or relationship between the variables measured. Here, the null hypothesis was that no significant difference would be found between computer models of speech pattern features and scores on the SPI in the prediction of future psychosis. Therefore, the null hypothesis is that speech pattern features and scores on the SPI will predict psychosis with similar accuracy. (Choice B) This study was observational, so no true independent variable was manipulated by the researcher to establish a causal relationship. The speech pattern features and SPI measure are predictive variables assumed to indicate the risk of future psychosis. (Choice C) All the study participants either met criteria for prodromal symptoms (preclinical signs of psychosis) or had a first-degree relative with schizophrenia. This study sought to determine whether speech pattern features or the SPI measure (not prodromal symptoms alone) could predict the development of psychosis. (Choice D) Researchers were interested in determining whether certain speech patterns or a standard clinical inventory better predicted the development of psychosis, not the severity of disease. Educational objective: The null hypothesis states that no significant difference or relationship exists between variables, whereas the alternative hypothesis assumes that a significant relationship or difference does exist between variables.

Passage Psychotic Disorders Are Characterized by a Loss of Contact with with Reality