Screening tests for mental health problems are usually brief self-administered questionnaires. They are useful for identifying people with the targeted mental health conditions (e.g. depression). They are designed to have “high sensitivity’ and capture the vast majority of their target mental health problems. However, they are not very “specific” to the mental health problem they are designed to identify. Therefore, a positive screen does not establish that the target mental health problem is indeed present but alerts to the need for further examination by a clinician.
The PHQ-9 is a commonly used self-administered, screening test for depression. The PHQ-9 scores each of the nine symptoms of major depression listed in the diagnostic instrument for mental disorders (DSM-IV). Each symptom can rated on a four-point scale with "0" meaning “not at all” and "3" meaning “nearly every day”.
The PHQ-9 scale and references related to validation studies can be found in https://patient.info/doctor/patient-health-questionnaire-phq-9
The C-SSRS was developed by Columbia University investigators. It rates an individual's degree of suicidal thoughts on a scale, ranging from "wish to be dead" to "active suicidal thoughts with specific plan and intent." Questions are phrased for use in an interview format, but the C-SSRS may be completed as a self-report measure. The scale identifies behaviors which may be indicative of an individual's intent to complete suicide.
The C-SSRS consists of 6 "yes" or "no" questions in which respondents are asked to indicate whether they have experienced several thoughts or feelings relating to suicide over the past month. Each question addresses a different component of the respondent's suicidal thoughts severity.
Question 1: desire to be dead
Question 2: suicidal thoughts
Questions 3-5: more specific suicidal thoughts and intent
Question 6: suicidal behavior over the respondent’s lifetime
If the respondent answers "yes" to Question 2, he/she is instructed to answer Questions 3-5. If the respondent answers "no" to Question 2, he/she may skip to Question 6.
Further information about the use of C-SSRS can be found in the Columbia Lighthouse Project webpage: http://cssrs.columbia.edu/