Abstract

The high degree of comorbidity among mental disorders has led research to focus on finding factors associated with the development of different types of psychopathology, called transdiagnostic factors. Ruminating is involved in the etiology and maintenance of a depressive disorder and recent evidence implies that ruminating also appears to be involved in the development of anxiety disorders. Two longitudinal studies investigated whether ruminating could explain the competing and prospective associations for the above mentioned disorders. One study involves adolescents and one study involves adults. It was found that ruminating was a mediator of the unequal association between symptoms of depression and anxiety among adolescents and a shared mediator of this association among adults. In prospective analyzes among adolescents, it appeared that the baseline of depression predicted an increase in anxiety and ruminating led to a complete mediation of this association. The same was found in adults, plus that baseline anxiety was a predictor of an ncrease in depression. This study shines light on the important trans-diagnostic factor ruminating within emotional disorders.

Introduction

Various transdiagnostic factors for depression and anxiety disorders are now known: elements of affect, attention, memory, reasoning, (repeated negative) thoughts and behavior. Repeatedly negative thinking is seen as thoughts that come back, are passive or relatively uncontrolled and have a focus on negative content. A specific type of this is ruminating. A pattern of the reaction to distress in which an individual passively and pervasively thinks about the annoying symptoms and the causes and consequences of these symptoms, in which active problem-solving strategies are not given room.

Ruminating appears to be a predictor for later depressive symptoms and their future onset, number of depressive episodes and their duration. Rumination is also often reported by clients as a symptom of an anxiety disorder, PTSD and social anxiety. Rumination can lead to anxiety and depression symptoms through various mechanisms. Experimental induction of ruminating in stressed individuals leads to: more mal-adaptive, negative thoughts, less effective problem solving, uncertainty and immobility in the implementation of solutions and less willingness to participate in distracting, mood lifting activities. In addition, ruminant people experience less social support and more social friction than non-ruminant people and are considered less favored by non-ruminant people.

Within this study, the prediction is tested whether ruminating is statically responsible for the relationship between symptoms of anxiety and depression, both cross-sectionally and longitudinally. By means of two samples; adolescents (11-14 years) and adults (25-75 years). If ruminating appears to be a transdiagnostic factor, there is expected to be evidence of the role of ruminating in the overlap of such symptoms at a random moment, over time, and in individuals at different points in their lives.

Method

Adolescent participants

The participants come from two high schools. The baseline sample consisted of 51.2% boys (total N = 1065). On measurement 2, 20.8% did not participate, on measurement 3, 20.4% of the baseline sample did not participate.

Adolescent measuring instruments

Depressive symptoms: Children's Depression Inventory (CDI), based on self-report. Anxiety symptoms: Multidimensional Anxiety Scale for Children (MASC), based on self-report. Ruminating: Children's Response Styles Questionnaire (CRSQ), based on self-reporting.

Adolescents procedure

Questionnaires were filled in during mentoring, the CDI and the CRSQ were taken on T1 and T3. All three lists were taken on T2. T1 plus 4 months = T2 plus 3 months = T3.

Adult participants

Called from random phone numbers in a specific part of the US. N = 1317 participated in baseline interview, with different age groups (25-35, 45-55, 65-75). T1 plus 1 year = T2 (14.1% of T1 did not participate in T2). Participants who completed both measurement moments took part in the study (N = 1132).

Adult measuring instruments

• Depressive symptoms: Beck Depression Inventory (BDI), based on self-report and the Hamilton Rating Scale for Depression (HRSD), filled in by interviewer. The interviewer also had to pay attention to non-verbal behavior.

• Anxiety symptoms: Beck Anxiety Inventory (BAI), based on self-report.

• Ruminate: Response Styles Questionnaire (RSQ), based on self-reporting.

Adult procedure

Trained interviewers conducted the self-reports and HRSD, usually at participants' homes.

Results

Cross-sectional analyzes: Within the adolescent sample, depression was significantly associated with anxiety. A significant mediation effect was found for ruminating between the symptoms of depression and anxiety. The same was found within the adult sample, although the mediation effect there was only partial. Longitudinal analyzes: Within the adolescent sample it was found that depression on T1 predicted an increase in lumination from T1 to T2 and that this increase in turn predicted an increase in anxiety from T1 to T3. Within the adult sample a significant indirect effect was found from anxiety on T1 to depression on T3 by means of ruminating. A significant indirect effect of depression on anxiety symptoms through ruminating was found.

Discussion

Transdiagnostic factors are relevant for improving theoretical models and clinical interventions. In doing this, broad and combined treatments can be set up, with little or no taking into account specific disorders. Rumination is responsible for a significant proportion of the overlap between depression and anxiety in both adolescents and adults (more visible in adolescents). This shows that rumination is actually a trans-diagnostic factor, and certainly needs to be involved in the combined treatments. This factor is more visible in adolescents, because internalizing problems are less differentiated in adolescents than in adults. Rumination can also play a greater role in the development of anxiety symptoms in adolescents compared to in adults.

Cross-sectional findings show that rumination plays an important role in explaining the competing symptoms of depression and anxiety, but does not provide information on whether ruminating is involved in the temporal progression from depression to anxiety and vice versa. The longitudinal findings show that rumination is a complete mediator between depression and later anxiety among adolescents. This shows that depressive symptoms predict an increase in ruminating over time and that this increase in ruminating is responsible for the development in anxiety symptoms. Moreover, this shows an increased risk of anxiety disorders among adolescents with depressive symptoms. Among adults, rumination is a significant mediator in the prospective associations of anxiety and subsequent depression and vice versa. This shows that ruminative responses to negative affect are associated with increased risks of developing co-morbid symptoms of emotional disorders over time.

Shortcomings: research largely based on self-report instead of DSM diagnoses, only looking at symptoms of anxiety and depression and no other comorbid symptomatology, different measurement methods between the two sample participants and finally it cannot be demonstrated that the associations found are causal know the connection.