The different instrument has been designed with the aim of assisting the clinician in screening and making a diagnosis of depression based on symptoms exhibited by the patient. Beck Depression Inventory (BDI) and the Centre for Epidemiologic Studies Depression Scale (CES-D) are used for this purpose. This study was carried out to ascertain the specificity and sensitivity of these instruments in assessing symptoms associated with depression and to identify clinical and psychosocial features between true positive and false positive participants.
The effectiveness of any diagnostic aid is its ability to identify true positives and true negatives i.e. sensitivity and specificity respectively. A diagnosis tool that is sensitive and specific to a given disorder remarkably improves diagnosis and treatment.
In this study, sample population was adolescent selected randomly into three cohorts. They were selected from nine senior high schools. This was to give a true representation of urban and rural populace in western Oregon. 1,709 students completed the initial (T1) assessment which comprised interview and answering questionnaires. The study was carried out from 1987 to 1989. However, only 61% of the sample population participated in the study. Ethical issues like written consent from parents (students were minors) was addressed, and adolescent was paid for participating in the study. In the second assessment (T2), 1507 (81%) adolescence returned for the test. The meant interval between the two tests was set at 13.8 months.
Initial participating adolescences (T1) were interviewed using the Schedule for Affective Disorders and Schizophrenia for School- Age Children (K-SADS) where nine major symptoms were used for diagnosis of depression. In T2, Long Interval Follow-up Evaluation (LIFE) was administered to participants. Bias was eliminated by training and supervision of diagnostic interviewers used for the study. All interviews were audio and video taped for review by the second interviewer who reviewed about 12% of the interviews.
During the study, three distinct groups were formed to include: the adolescent who score greater than 27 (one standard deviation above the mean of the sample on the CES-D) and met diagnostic criteria for major depression forming group 1. This group was designated as the ‘true positive group’, group 2 (false positive) were adolescences scoring above 27 but did not met the diagnostic criteria and group 3 designated as the true negative group was adolescences that scored less than 27 and also didn’t meet the diagnostic criteria.
The results showed that adolescences that were diagnosed with depression (true positive) showed a marginal increase of CES-D score when compared to participants in the false positive group (individuals who meet criteria for the screening procedure but do not meet psychiatric diagnostic criteria). However, it was observed that only true positive participants met the diagnostic criteria for the major depressive disorder. Although individuals in the false positive group didn’t meet the diagnostic criteria, they exhibited symptoms that didn’t differ with those in the true positive group on the measure of psychosocial dysfunction. Individuals in the false positive group showed an increased level of future psychological disturbance that participants in the true negative group and as such, such individuals should not be neglected but further evaluated and monitored.
Participants in the true positive and false positive group where differentiated mainly on suicidal attempt because they both shared similar psychosocial features because of the perception of symptoms.
The study, however, had restrictions because the sample population was adolescence and as such, results may not apply to older individuals and to children. It is recommended that researchers and clinician should focus on individuals in the false positive group because of their peculiar psychosocial problems due to a high score of self-report depression even though they don’t meet the DSM-III-R criteria for the diagnosis of depression.
You have just read a summary of the research paper: Gotlib, Ian H., Peter M. Lewinsohn, and John R. Seeley. “Symptoms versus a diagnosis of depression: differences in psychosocial functioning.” Journal of consulting and clinical psychology 63.1 (1995): 90-100