Depressive disorders are severe mental illnesses associated with high societal (Lépine & Briley, 2011) and individual burden (Hirschfeld et al., 2000; Judd et al., 2000). Main symptoms of depressive episodes are sad mood, diminished interest in activities, and fatigue or low levels of energy, lasting for at least two weeks (American Psychiatric Association, 2013). Cognitive behavioural theories explain the aetiology of depression by diatheses-stress models with dysfunctional attitudes (Abela & D'Alessandro, 2002; Beck, 1963; Fuhr, Reitenbach, Kraemer, Hautzinger, & Meyer, 2017; Köhler et al., 2015), rumination (Nolen-Hoeksema, 1991, 2004) (Olatunji, Naragon-Gainey, & Wolitzky‐Taylor, 2013; Raeisizadeh & Mohammadi, 2018; Ruscio et al., 2015) and attributional style (Abramson, Metalsky, & Alloy, 1989; Alloy, Abramson, Metalsky, & Hartlage, 1988; Liu, Kleiman, Nestor, & Cheek, 2015) as major psychological factors. In the general population, lifetime prevalence of depressive disorders is high, ranging from 6.6% in Japan to 21.0% in France (Bromet et al., 2011). Ten to seventeen percent of individuals with depressive disorders develop a chronic course (Steinert, Hofmann, Kruse, & Leichsenring, 2014), spending approximately 20.8 percent of their lifetime in depression (Vos et al., 2004). Although cognitive behavioural psychotherapy is effective in the treatment of depression in the short-term, 54% of initial responders relapse in a 2-year period after treatment (Vittengl, Clark, Dunn, & Jarrett, 2007). Furthermore, depressive disorders are associated with heightened risk for self-directed aggression compared with the general population.
Self-directed aggressive behaviour describes any behaviour intended to harm oneself in active or passive ways (VandenBos, 2007). Self-directed active aggressive behaviour is defined as an active engagement in self-harm (e.g., cutting oneself, self-punishment; Buss, 1961), whereas self-directed passive aggressive behaviour is defined as harmful inactivity (e.g., omission of one´s own needs or reduced self-reward; Turp, 2007). The link between self-directed aggression and depression may be explained by the self-control model of depression (Rehm, 1977), which is based on Kanfer's (1971) behavioural self-control model. According to the self-control model of depression, depressive symptoms are a result of a maladaptive feedback loop of dysfunctional self-monitoring and distorted self-evaluation, which leads to reduced self-reward (self-directed passive aggressive behaviour) and increased self-punishment (self-directed active aggressive behaviour).
The above mentioned cognitive factors are assumed to contribute to this feedback loop: Rumination represents a form of dysfunctional self-monitoring (Donaldson, Lam, & Mathews, 2007; Mor & Winquist, 2002) while dysfunctional attitudes (Otani, Suzuki, Matsumoto, & Shirata, 2017) and negative attributional style (Rozensky, Kravitz, & Unger, 1981) contribute to a distorted self-evaluation. Correlations between self-directed active aggression with depressive symptoms, rumination (Nicolai, Wielgus, & Mezulis, 2016; Rogers & Joiner, 2017), dysfunctional attitudes (Chioqueta & Stiles, 2007; Ranieri et al., 1987), and negative attributional style (Abramson et al., 2002; Fox et al., 2015; Ribeiro, Huang, Fox, & Franklin, 2018) have been demonstrated multiple times. On the other hand, research about self-directed passive aggressive behaviour is scarce (Turp, 2007). However, a recent study found a moderate association between self-directed passive aggressive behaviour and depressive symptoms in an inpatient sample (Schanz et al., 2021). Thus, intensified research efforts about the role of self-directed passive aggressive behaviour in depression seem a promising avenue of identifying new prevention and treatment options for depressive disorders that are much needed considering the enormous burden of depression (Bromet et al., 2011; Steinert et al., 2014; Vittengl et al., 2007; Vos et al., 2004)
Study aims
Study 1 (preregistered at German Clinical Trials Register: DRKS000140051) aims to determine whether the correlation between self-directed passive aggressive behaviour and depressive symptoms found in inpatients (Schanz et al., 2021) holds-up in patients seeking outpatient psychotherapy. Furthermore, Study 1 investigates the hypothesis that depressed patients report higher levels of self-directed passive aggressive behaviour than patients with other mental disorders.
Based on the self-control model of depression, Study 2 (preregistered at German Clinical Trials Register: DRKS000190201) aims to test the assumptions that self-directed passive aggressive behaviour is associated with dysfunctional self-monitoring (rumination) and self-evaluation (dysfunctional attitudes and negative attributional style) processes and that it mediates their association with depressive symptoms. Additionally, Study 2 examines whether self-directed passive aggressive behaviour accounts for a unique amount of variance in depressive symptoms when controlling for the described cognitive factors.