Research master thesis | Psychology (research) (MSc)
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Objective: This study aimed to clarify the relationship between the course of core depressive symptoms and the course of insomnia symptoms in older adults with a depressive disorder, and to...Show moreObjective: This study aimed to clarify the relationship between the course of core depressive symptoms and the course of insomnia symptoms in older adults with a depressive disorder, and to identify predictors of an unfavorable versus a favorable course of core depressive symptoms and insomnia symptoms. Method: We examined 329 older adults (median age 69 (IQR 65-75), 66.9% women) with a depressive disorder within the Netherlands Study of Depression in Older persons (NESDO), a naturalistic cohort study with a six-year follow-up and assessments every six months in between. Core depressive symptoms and insomnia symptoms were assessed with 14 and 3 items, respectively, from the Inventory of Depressive Symptomatology (IDS). We applied growth mixture modelling to identify classes of participants with similar trajectories of core depressive symptoms and insomnia symptoms. The association between core depressive and insomnia symptom trajectories was examined with a chi-squared test. Finally, we investigated predictors of class membership for core depressive symptoms and for insomnia symptoms using multinomial logistic regression. Results: We identified three trajectories of core depressive symptoms: high and stable (22.2% of participants were assigned to this class), moderate and declining (37.4%), and low and declining (40.4%). We identified four trajectories of insomnia symptoms: high and stable (23.1%), moderate and stable (55.6%), low and increasing (7.6%), and moderate and declining (13.7%). There was a significant association between core depressive and insomnia symptom trajectories, in particular for the most and least favorable trajectories. Number of chronic diseases, a comorbid anxiety disorder, and functional limitations predicted less favorable core depressive symptom trajectories. We found no predictors for insomnia symptom trajectories. Conclusion: Persistent insomnia symptoms are highly prevalent in older adults with depression, even in those with improving core depressive symptoms. This highlights the need for separate treatment of insomnia symptoms in addition to depression interventions.Show less
Sleep disturbances and disorders have been linked with increased suicidality. Research is just beginning to explore using sleep interventions to reduce suicidality, but until now has not considered...Show moreSleep disturbances and disorders have been linked with increased suicidality. Research is just beginning to explore using sleep interventions to reduce suicidality, but until now has not considered how sleep and suicidality change across the lifespan, and how that may impact the effectiveness of interventions. This study is the first meta-analysis examining whether sleep interventions are effective for reducing suicidality, and whether age has an impact on outcomes. A search was conducted on February 8th, 2022, using PubMed, PsycINFO and Web of Science. Article selection and data extraction was performed using the Covidence Systematic Review software. Twenty-one articles were included in this study. Sleep interventions were categorized as cognitive behavioural therapies (CBTs), circadian rhythm therapies (CRTs) and pharmacological therapies (PTs). Age groups were defined as adolescents (15-18), young adult college students (18-24), and adults (18-64). Sleep interventions overall had a small, significant effect size in reducing suicidality. CBTs and CRTs significantly reduced suicidality with small and medium effect sizes, but PTs did not. When stratified by age group, results found that sleep interventions overall significantly reduced suicidality in adolescents and adults with medium effect sizes, but there was no significant reduction in young adults. The results of this study suggest that sleep interventions may reduce suicidality and serve as a versatile and transdiagnostic treatment approach that deserves more focus. It also provides preliminary evidence that age may be a possible moderator for treatment effectiveness, and that future studies should include age as a moderator.Show less
Depression and insomnia are prevalent disorders which are often found to occur comorbidly. Compared to suffering from one disorder alone, a comorbidity is related to a higher symptom burden and...Show moreDepression and insomnia are prevalent disorders which are often found to occur comorbidly. Compared to suffering from one disorder alone, a comorbidity is related to a higher symptom burden and reduced treatment success. Still, only a number of studies focus on the psychological risk factors for the onset and maintenance of depression and insomnia. This study hypothesized that high levels of perfectionism and rumination can predict an increase in depressive symptoms and sleep disturbances. In a sample of 69 healthy university students, an online survey with a series of self-report questionnaires was administered. The study confirmed the already established finding of a comorbidity between depressive symptoms and sleep disturbances. Regarding the main hypotheses of this study, multiple regression analyses yielded that rumination significantly predicts depressive symptoms as well as sleep disturbances, while perfectionism was not a significant predictor of an increase in depressive symptoms and sleep disturbances. Existing literature suggests that this could be either explained by 1) the mediating effect of rumination between perfectionism and sleep disturbances or depressive symptoms and that 2) maladaptive, but not adaptive, perfectionism has detrimental effects on mood and sleep. Future research should investigate these hypotheses and additionally examining whether other factors, for instance worry or stress, might be relevant in predicting depressive symptoms and sleep disturbances. Further knowledge about the mechanisms behind the comorbidity between depression and insomnia is relevant in order to improve existing treatment approaches as well as establish prevention measures which target these risk factors.Show less
