Sleep problems act as a mediator between chronic disease and depression

New research has revealed that individuals who have suffered a stroke, as well as those with heart disease, diabetes, and hypertension, have increased odds of developing depression. Additionally, individuals with sleep problems also face a higher likelihood of experiencing depression. The paper was published in the Frontiers in Psychology.

Depression is a mental health disorder characterized by persistent sadness, loss of interest in activities, and emotional or physical fatigue. It affects mood, cognition, and daily functioning, leading to difficulties in work, relationships, and self-care. Symptoms can include changes in appetite, sleep disturbances, feelings of worthlessness, and difficulty concentrating.

The causes of depression are not fully understood, but numerous factors that increase its likelihood have been identified. These include genetic predisposition, neurochemical imbalances, stressful life events, and underlying medical conditions. If left untreated, depression can significantly reduce quality of life and increase the risk of suicidal thoughts and behaviors. Treatment options include therapy (such as cognitive-behavioral therapy), medications (such as antidepressants), lifestyle changes, and support networks. However, current treatments are not highly effective, with at least 30% of cases that receive high-quality treatment failing to achieve remission of symptoms.

Study author Ming Tan and her colleagues note that chronic diseases and sleep problems play a significant role in depression. They hypothesized that sleep problems may mediate the link between chronic diseases and depression—meaning that chronic diseases could lead to sleep disturbances, which in turn may increase susceptibility to depression.

To investigate this possibility, the researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES), collected between 2005 and 2018. NHANES is a large-scale study conducted by the Centers for Disease Control and Prevention (CDC) every two years. It employs a complex sampling procedure to ensure the sample is representative of the overall population of the United States.

The analysis included data from 10,710 adult participants, with an average age of 46 years. Among them, 3% had depression, 32% had hypertension, 10% had diabetes, 9% had heart disease, 3% had experienced a stroke, and 8% reported trouble sleeping.

The researchers used data on depression symptoms (measured by the Patient Health Questionnaire-9), medical history, and sleep duration. They also accounted for participants’ gender, age, body mass index, race, income status, smoking status, drinking status, education level, and marital status.

The results showed that participants who had experienced a stroke had 71% higher odds of suffering from depression compared to those who had not. Similarly, individuals with heart disease had 42% higher odds of depression, while those with hypertension had 25% higher odds compared to individuals without these conditions. Additionally, individuals with sleep problems had twice the odds of suffering from depression. In contrast, longer sleep duration was associated with lower odds of depression.

The researchers tested a statistical model to examine whether sleep problems mediate the relationship between chronic diseases and depression. The results supported the possibility of such mediation.

“Chronic diseases and sleep problems may increase the likelihood of depression among U.S. adults, with sleep serving as a mediator between chronic diseases and depression,” the study authors concluded.

The study sheds light on the links between chronic diseases, sleep problems, and depression. However, it is important to note that the study’s design does not allow for causal inferences to be drawn from the results.

The paper, “Sleep as a mediator between chronic diseases and depression: a NHANES study (2005–2018),” was authored by Ming Tan, Haihong Zhao, Ruya Nie, Pingping Deng, and Cuixiao Wang.