The Influence of Anxiety on the Relationship Between Depression and Sleep Disturbances

The influence of anxiety on the relationship between depression and

sleep disturbances

Unit code: PSY4032

Due date: 17th June, 2018

Tutor: Laura Connolly

Live class: Thursday 8:00 – 9:00pm

Word Count: 1498 words

Abstract

This study aimed to determine the relationship between depressive symptomology and poor sleep/sleep disturbance in a non-clinical population. It then aimed to determine the extent state anxiety influences this relationship. It was hypothesised that there would be a significant correlation between depressive symptomology and poor sleep/sleep disturbance in the non-clinical population. It was further hypothesised that this relationship would remain significant after state anxiety was controlled for. Psychology students from Monash University (N=321, mean age = 24.18) were asked to voluntarily complete the Pittsburg Sleep Quality Index to measure sleep quality and the DASS­21 to measure depression, anxiety and stress. The results showed a significant positive correlation between depressive symptomology and poor sleep/sleep disturbance and a significant, positive partial correlation after state anxiety was controlled for. It was concluded there is a relationship between depressive symptoms and sleep disturbance which is independent of state anxiety.

The influence of anxiety on the relationship between depression and sleep disturbances

Sleep occupies roughly a third of each day throughout most people’s lives and helps people live a healthy and productive life. Disturbances of sleep vary in symptoms, onset and duration. They range from not sleeping to sleeping too much to waking during a sleep cycle, nightmares, difficulties falling asleep and difficulty sleeping due to medications, medical conditions, substance abuse and mental disorders. Inadequate sleep, of either duration or quality, and its subsequent daytime consequences are very common, affecting 33-45% of Australian adults (Adams, Appleton, Taylor, McEvoy & Antic, 2017).

The Diagnostic and Statistical Manual of Mental Disorders 5th ed (DSM-5) states that depression is a common and serious medical illness that negatively affects how you feel, the way you think and how you act. Depression has been shown to have a high co­morbidity with anxiety. Anxiety disorders differ from normal feelings of nervousness or anxiousness and involve excessive fear or anxiety (American Psychiatric Association, 2013). It is estimated that 60% of people diagnosed with depression also meet the criteria for clinical anxiety disorder (Kaufman & Charney, 2000).

The DSM-5 indicates that sleep problems often co-occur with depression and anxiety (American Psychiatric Association, 2013). Buysse et al. (2008) studied depression and insomnia and found one of the most reliable risk factors for insomnia is depression and that the reverse is the same. Manber et al. (2008) support the concept of insomnia and depression being comorbid rather than insomnia being a symptom. Atalay (2011) demonstrated that 40­60% of clinical patients suffering from insomnia carried symptoms associated with depressive and anxiety disorders. The results further established no significant correlation between depression and insomnia but rather demonstrated state anxiety as more associated with insomnia. The conclusion was that sleep difficulties might be the result of interactions between insomnia and state anxiety. Alternatively, Johnson, Roth and Breslau (2006) conducted a directional study between insomnia, anxiety and depression in adolescents to understand potential etiological connections. Their results showed there is a definite relationship between insomnia and both anxiety and depression, independent of each other.

From the previous research and literature it is evident that a relationship exists between sleep disturbance and depression and anxiety. There has been much previous research looking at the relationship of depression and sleep disturbance but little research that looks specifically at the influence of state anxiety. It is important to establish what role anxiety plays in sleep disturbance as it may help to better understand sleep disturbance and target treatment for a better clinical outlook for patients and to gain further insight that may direct further study and research.

This study aimed to establish the extent to which state anxiety influences the relationship between sleep disturbances and depressive symptomology in order to understand the role anxiety plays in sleep disturbance which in turn may lead to more effective treatment. It was hypothesised that there will be a significant correlation between depressive symptomology and poor sleep/sleep disturbance in the non-clinical population. It was further hypothesised that this relationship would remain significant after state anxiety was controlled for.

Method

Participants

Participants were recruited by convenience sampling from the Graduate Diploma of Psychology students of teaching period three of 2018 of Monash University. There were 321 participants that completed the study. They ranged in age from 19 to 60 years old, with a mean of 24.18 years old (SD= 7.70). There were 251 female and 70 male participants.

Design

The study was a non-experimental, correlational study with state anxiety as the predictor variable and depression and sleep disturbance as the criterion variable. Anxiety and depression were operationalised as scores on the DASS­21 and sleep disturbances were operationalised with a score greater than five indicating ‘poor sleep’ on the PSQI.

Materials

Pittsburgh Sleep Quality Index (PSQI) Buysse, Reynolds, Monk, Berman and Kupfer (1989). The PSQI consists of ten items, some of which contain multiple parts. The total score on the PSQI can range from 0 to 21, with higher scores indicating worse sleep quality. There are seven component scores that share a high internal consistency (Cronbach’s α= .83), and good overall test-retest reliability (r= 0.85) (Buysse et al. 1989). The PSQI seven component scales are sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, use of sleeping medication, and daytime dysfunction.

Depression, Anxiety and Stress Scale - 21