Self-report measures of psychological distress or psychopathology are widely used and can be easily implemented as psychiatric screening tools. Positive psychological constructs such as vitality/optimism and work functioning have scarcely been incorporated. We aimed to develop and validate a psychological distress instrument, including measures of vitality and work functioning. A patient sample with suspected depressive, anxiety, and somatoform disorders (N=242) and a reference sample of the general population (N=516) filled in the 48-item Symptom Questionnaire (SQ-48) plus a battery of observer-rated and self-report scales (MINI Plus, MADR, BAS, INH, BSI), using a web-based ROM programme. The resulting SQ-48 is multidimensional and includes the following nine subscales: Depression (MOOD, six items), Anxiety (ANXI, six items), Somatization (SOMA, seven items), Agoraphobia (AGOR, four items), Aggression (AGGR, four items), Cognitive problems (COGN, five items), Social Phobia (SOPH, five items), Work functioning (WORK, five items), and Vitality (VITA, six items). The results showed good internal consistency as well as good convergent and divergent validity. The SQ-48 is meant to be available in the public domain for Routine Outcome Monitoring (ROM) and can be used as a screening/ monitoring tool in clinical settings (psychiatric and non-psychiatric), as a benchmark tool, or for research purposes.
The measurement of self-reported psychological distress is prominently represented in both the psychological and psychiatric literature. Historically, assessment of the general psychological status of individuals by means of self-report dates back to the First World War, and the development of the so called Personal Data Sheet by Woodworth (1918). Woodworth's scale provided a means for each man to “interview himself” and created a historical benchmark for a new modality of psychological measurement (Derogatis and Melisaratos, 1983). Nowadays, self-report measures of psychological distress or psychopathology are widely used as psychiatric screening tool in clinical settings and epidemiological studies.
Many validated self-report questionnaires for measuring psychological distress or psychopathology have been developed (see Dohrenwend et al., 1980, Ritsner and Ponizovsky, 1998, Ritsner et al., 2002 and Luckett et al., 2010). For instance, Symptom Checklist-90 (SCL-90; Derogatis et al., 1973) and its short-form Brief Symptom Inventory (BSI, BSI-18; Derogatis and Melisaratos, 1983 and Derogatis, 2001); General Health Questionnaire (GHQ; Fichter et al., 1988); 50-Item Brief Symptom Rating Scale (BSRS-50; Lee et al., 1990); Talbieh Brief Distress Inventory (TBDI; Ritsner et al., 1995); Mood and Anxiety Symptoms Questionnaire (MASQ; Watson et al., 1995a and Watson et al., 1995b) and its short-form MASQ-D30 (Wardenaar et al., 2010).
Studies concerning the above-mentioned instruments often used multiple related concepts interchangeably: concepts such as psychological distress, emotional distress, affective distress, mental distress, global distress, symptom distress, psychiatric distress, general psychopathology. Notably, however, these instruments have been useful for assessing the aggregate level of nonspecific psychological distress, and not for diagnosing particular psychiatric disorders (Dohrenwend et al., 1980, Coyne, 1994 and Ritsner and Ponizovsky, 1998). Elevated scores on the scales are an indicator of possible psychopathology and could assist the clinician to predict the probability of individuals meeting criteria for disorder (Dohrenwend et al., 1980, Boulet and Boss, 1991 and Oakley Browne et al., 2010).
More specifically, “psychological distress” can be described as a reaction of an individual to external and internal stresses, characterized by a mixture of psychological symptoms, such as sadness, anxiety, confused thinking, hopelessness, helplessness, dread, and poor self-esteem (Ritsner et al., 2002). In addition, some instruments, such as the BSI, include somatic distress. Psychological distress was originally considered as a uni-dimensional construct. However, more recent research suggested a multidimensional structure of psychological distress. For instance, Schwannauer and Chetwynd (2007) found a three-factor model of depression, anxiety, and general psychological distress.
The assessment of psychological distress is important both in health care and mental health care, because of its relevance for compliance, quality of life, prediction of treatment outcome and planning of treatment (Kalman, 1993, Buchanan, 1996, Awad et al., 1996 and Ritsner et al., 2002). Research has shown that pervasive distress may affect the course of illness, symptom expression, as well as levels of social relationships and adaptation (Feldman et al., 1995, Laatsch and Shahani, 1996, Barker and Orrell, 1999 and Ritsner et al., 2002).
More recently, there is a growing awareness that, in addition to distress-based measures, attention must also be paid to more positive constructs such as vitality/optimism (van Fenema et al., 2012 and Giltay et al., 2004) and work functioning (Burdick et al., 2010 and Verboom et al., 2011). The importance of both constructs has already been demonstrated. For instance, Burdick et al. (2010) showed that poor work functioning was significantly related to subsyndromal depression and course of illness. Emotional vitality, on the other hand, seems to be a critical positive psychological factor (related to but separate from optimism) that may promote psychological health as well as physical health (Wyshak, 2003, Giltay et al., 2004, Rozanski and Kubzansky, 2005 and Kubzansky and Thurston, 2007). In addition (lack of) vitality/optimism has been shown to be an important defining feature of depression, with distinct implications for prognosis (Giltay et al., 2006).
To date, there is no psychological distress instrument available that also measures vitality and work functioning. Another shortcoming is that most self-report instruments are usually not free of charge, which particularly in Routine Outcome Monitoring (ROM) with repeated assessment is a costly matter. In line with these shortcomings, the purpose of this study was to develop and validate a brief psychological distress instrument (SQ-48), which also includes measures of vitality and work functioning (or study). In addition, the SQ-48 is developed as a public domain questionnaire, freely available to clinicians and researchers. This practical advantage is in line with growing efforts in other scientific areas to develop instruments that are free of charge (Moessner et al., 2010).
The SQ-48 is meant as a screening tool to improve diagnostic recognition in clinical and nonclinical settings. Therefore, the present study used both clinical and nonclinical samples: a patient sample with suspected depressive, anxiety, and somatoform disorders, and a reference sample of the general population. In this way, the SQ-48 could be useful as a monitoring tool in the context of ROM (Luckett et al., 2010, Moessner et al., 2010 and Carlier et al., 2012), for benchmark purposes (Hermann et al., 2006, Minami et al., 2008 and Cleary et al., 2010), or as a research tool in for instance epidemiological studies.
