Schizophrenia Screening Tests

The Positive and Negative Syndrome Scale (PANSS) evaluates the positive and negative symptoms of schizophrenia. In this scale, positive symptoms refer to an excess or distortion of normal functions, such as hallucinations and delusions. Negative symptoms, on the other hand, represent a loss of normal functions such as effect and motivation.

The PANSS schizophrenia scale is a 30-item questionnaire. It was conceived as an operationalized, drug-sensitive instrument that provides a balanced representation of both positive and negative symptoms and determines their relationship to one another. In the 45-minute clinical interview, the patient is rated from 1–7 on 30 different symptoms based on the interview, as well as reports from family members or hospital workers. Studies have found this questionnaire to be both reliable and valid.

The Scale for the Assessment of Negative Symptoms (SANS), unlike the PANSS, is only used to measure the negative symptoms of schizophrenia. The SANS schizophrenia scale is a questionnaire comprised of 19 questions and is split into five domains of negative symptoms. Within each of these domains, these symptoms are rated from 0 (absent) to 5 (severe). Because it contains more questions than questionnaires that are typically used to screen for schizophrenia, it may yield more interpretable findings.

The Brief Psychiatric Rating Scale (BPRS) does not focus solely on schizophrenia symptoms. Instead, it is used to measure symptoms such as depression, anxiety, hallucinations and other similar behaviors. It is a 24-item questionnaire on which symptoms are rated on a 1–7 scale. The BPRS schizophrenia scale is slightly older than other questionnaires. However, the BPRS has been shown to be particularly good at capturing affective symptoms related to the manic dimension of schizophrenia.

The Clinical Global Impression-Schizophrenia (CGI-SCH) scale was designed to assess positive, negative, depressive and cognitive symptoms of schizophrenia. Research suggests that the CGI‐SCH scale is a valid and reliable questionnaire to evaluate severity and treatment response in schizophrenia. It has ten questions that are answered on a 1–7 scale. Simply put, it is simple, short, valid and has clinical value.

The Calgary Depression Scale for Schizophrenia (CDSS) is the only questionnaire designed for the assessment of depression in schizophrenia, and it differentiates between depression and the negative and positive symptoms of schizophrenia. It has nine questions that are answered on a 0–3 scale. One study suggests that the CDSS may provide the best assessment for depression in patients with schizophrenia.