COPD patients with smoking history face higher risk of developing ADHD but a slight reduction in Alzheimer's disease risk: Study

Conversely, the researchers did not observe any causal association between COPD and psychiatric disorders among patients who never smoked. The findings were published online in the International Journal of Chronic Obstructive Pulmonary Disease.

"Never-smokers with COPD showed no causal association with psychiatric disorders. In contrast, ever-smokers with COPD experienced a higher risk of ADHD (OR: 2.303) but experienced a slight reduction in the risk of Alzheimer’s disease (OR: 0.994)," the researchers reported.

Chronic obstructive pulmonary disease is a progressive inflammatory respiratory condition characterized by symptoms like limited physical activity, dyspnea, and partially reversible airflow obstruction. Clinically, COPD patients often present with comorbidities such as hypertension, coronary heart disease, psychological disorders, cognitive impairment, and other ailments, indicating that COPD should no longer be considered exclusively as a pulmonary disorder.

Although there has been significant scientific progress in the past few years, the potential relationship between COPD and mental illness remains debatable. To shed light on the same, Qinxia Zhang, Department of Respiratory Medicine, The First People’s Hospital of Fuyang, Hangzhou, Zhejiang, People’s Republic of China, and colleagues retrieved COPD data from the genome-wide association studies (GWAS) directory and data on mental illnesses, including obsessive-compulsive disorder, schizophrenia, post-traumatic stress disorder, Alzheimer’s disease, major depressive disorder, panic disorder, ADHD, bipolar disorder, multiple disabilities, and schizophrenia, from the Psychiatric Genomics Consortium.

To explore the association between COPD and mental illnesses, a two-sample Mendelian randomization (MR) approach was applied, with subgroup analyses based on smoking history.

The key findings of the study were as follows:

• The two-sample MR analysis revealed no causal link between overall COPD and the development of common psychiatric disorders.
• Subgroup analyses based on smoking history showed no causal association between never-smokers with COPD and the occurrence of psychiatric disorders.
• Ever-smokers with COPD were associated with a significantly increased risk of ADHD (OR: 2.303) and a modestly reduced risk of Alzheimer’s disease (OR: 0.994).

The findings revealed that ever-smokers with COPD face a higher risk of ADHD development but may reduce the risk of Alzheimer’s disease to some extent. In COPD patients without a smoking history, no causal association with psychiatric disorders was observed.

"Therefore, there is a need to pay attention to preventing psychiatric disorders in COPD patients with a smoking history," the research team concluded.

Reference:

Zhang Q, Zhang H, Xu Q. Association of Chronic Obstructive Pulmonary Disease with Risk of Psychiatric Disorders: A Two-Sample Mendelian Randomization Study. Int J Chron Obstruct Pulmon Dis. 2024;19:343-351. https://doi.org/10.2147/COPD.S442725