Psychology Data Collection Project

Hypothesis: A positive correlation exists between generalized anxiety and depression

What is the correlation? 0.276

Generalized Anxiety Disorder And Psychiatric Comorbidities Such As Depression, Bipolar Disorder, And Substance Abuse

Article Summary

Generalized anxiety disorder (GAD) is one of the main anxiety disorders and is in most cases comorbid with a number of other psychiatric disorders. This makes it even harder for the medics to diagnose or even treat the disorder. In a study cited in this article, a substantially high percentage of individuals with major depressive disorders (MDD) who were assessed using a semi-structured diagnostic interview were diagnosed with GAD. According to epidemiological data from the National Comorbidity Survey (as cited in this article), 67% of the individuals with GAD have lifetime unipolar depressive disorder. The extensive link between the two conditions has even prompted some to suggest that GAD be reclassified as a mood disorder. This research also points out the high costs that are associated with GAD. In addition to predisposing a person to MDD, it also leads to increased medical utilization as well as unpleasant impacts a person’s workplace productivity (Simon, 2009, p. 10).

Anxiety disorders occur relatively earlier in life and thus as many studies have suggested, they occur prior to the first episode of MDD. It is thus viewed as a prodrome for MDD. In fact, a study cited in this article further suggests that a person with GAD has an increased possibility of developing a major depressive episode in the course of the year as compared to a person with no anxiety disorder. These findings are however conversed by another set of study among the adults and children which suggests a varied order of onset. In this case, a significant proportion is seen to have the onset of MDD come before GAD. Treatment of GAD can offset the chances of one contracting secondary MDD. The study suggests that further research be conducted on both the pharmacotherapy and psychotherapy interventions for GAD to prevent occurrence of MDD. It however points out that presence of anxiety comorbidity in patients with primary depression can interfere with treatment response (Simon, 2009, p. 11).

According to our data, there is a weak positive correlation between generalized anxiety and depression i.e. 0.28. In the aforementioned research, there is strong evidence indicating that there is a positive correlation between the two variables. The weak correlation can be explained by the uncertainty on which of the two conditions i.e. GAD and MDD precede the other i.e. the reciprocal influence factor. As can be drawn from the research, there are situations where MDD actually leads to GAD.

Divergence can also be explained by the fact that correlation does not necessarily imply causation. Whereas a statistical test may indicate that there is a correlation between variables, it may not necessarily mean that one variable causes the other i.e. the weak correlation (~0.3) does not disapprove our hypothesis that GAD predisposes one to MDD. It is just an evidence of the reciprocal influence between the two variables. The graph below represents the weak correlation between generalized anxiety and depression using data from our results.

Generalized anxiety versus Depression

Hypothesis 2: A positive correlation exists between loneliness and depression

What is the correlation? 0.539

Article: Loneliness as a Specific Risk Factor for Depressive Symptoms: Cross-Sectional and Longitudinal Analyses

Article Summary

This article seeks to find out how much loneliness acts as a unique factor for depressive symptoms. The article begins by acknowledging the role played by depressive symptomatology as an important indicator of general well-being and health among the middle-aged and the older adults. According to Weiss (as cited in the article), loneliness is a gnawing chronic disease that that exhibits no redeeming features. It has for long been a correlate of depressive symptoms.  As a measure for loneliness, the revised UCLA Loneliness scale is frequently used. It is a 20-item questionnaire focusing on general feelings of social isolation and dissatisfaction with a person’s social interaction (Cacioppo, Waite, Hawkley, & Thisted, 2006, p. 140).

Previous studies also support this hypothesis. Alpass and Neville (as cited in the article), conducted a research and reported a significant association between loneliness and depressive symptoms among 217 older men in New Zealand. In their research, they had controlled for variables such as age, education, income and social support. Another research that is quoted in the article is one by Hagerty and Williams that also found a significant association between loneliness and depressive symptoms in their sample which comprised of undergraduates and patients with major depressive disorders. Again, this research had controlled variables such as social support, social conflict and sense of belonging (Cacioppo, Waite, Hawkley, & Thisted, 2006, p. 141).

In order to determine this relationship, two studies were conducted after controlling for demographic variables and psychosocial risk factors. The first study used the 2002 wave of the HRS which is a nationally representative, longitudinal study of persons born in 1947 or earlier who were interviewed by phone. The second study, the researchers used the first year of data that was collected in Chicago, health, Aging, and Social Relations Study (CHASRS), a population-based study of persons born between 1935 and 1952 living in a large metropolitan area who were tested individually in their laboratory. In the first study, a three-item scale was used to gauge the feelings of social isolation using telephone interview.

The second study used a R-UCLA, which as aforesaid is a 20-item questionnaire that measures people’s general feelings of social isolation, loneliness, and dissatisfaction with one’s social interactions. Results from the study 1 replicated findings from prior cross-sectional research that indicated high levels of reported loneliness are indeed linked to elevated levels of depressive symptoms. A hierarchical regression analysis of the second study also replicated major findings of study. Latent variable growth models however revealed reciprocal influences over time between the two variables i.e. loneliness and depressive symptomatology (Cacioppo, Waite, Hawkley, & Thisted, 2006, p. 146).

Research findings

In our study as well, there was a moderate positive correlation between loneliness and depression i.e. 0.539 ~ 0.54. The results from my research clearly do support the findings from the aforementioned research. The moderate correlation can be explained. As aforementioned, correlation does not necessarily imply causation. As can be drawn from the latent variable growth model study in the research, there is a reciprocal influence over time between the two variables. This implies that it is not always that loneliness causes depression, rather, vice versa can also be true i.e. depression in the long term can cause loneliness. This can be the reason for the moderate correlation. Without the reciprocal influence, the correlation would be strong. The scatter graph below is a representation of the moderate positive correlation between loneliness and depression from our results.