Randomized controlled trial of acupuncture for anxiety and depression in patients with chronic insomnia

Chronic insomnia is a health problem affecting approximately 10 to 20% of the world's population, and its incidence has been increasing significantly because of the accelerated pace of modern life, work pressure, and inadequate lifestyle habits. This condition does not occur in isolation: approximately 70% of patients with chronic insomnia also present depressive symptoms, while 20 to 30% develop anxiety symptoms. The relationship between these problems is bidirectional, meaning that insomnia can cause anxiety and depression, which in turn worsen sleep symptoms. This interrelationship can seriously affect patients' quality of life and, in extreme cases, increase the risk of suicide.

Acupuncture, one of the most traditional practices of Chinese medicine, has been widely studied as a treatment for sleep disorders. Previous research has shown that acupuncture is safe and effective for treating insomnia, offering lasting benefits and good patient acceptance. However, most studies focus only on clinical efficacy, leaving gaps regarding the mechanisms by which acupuncture acts. Substances such as serotonin and cortisol play important roles in the development of insomnia and associated mood disorders.

Cortisol, known as the stress hormone, tends to be elevated in patients with insomnia and depression, while serotonin, a neurotransmitter that regulates mood and sleep, is usually decreased.

This study aimed to assess whether acupuncture can simultaneously improve sleep quality, reduce anxiety and depression, and normalize blood levels of cortisol and serotonin in patients with chronic insomnia. The investigators conducted a randomized controlled clinical trial in which 60 patients with chronic insomnia were randomly divided into two groups of 30 people each. The first group received true acupuncture at specific points traditionally used to treat insomnia: Baihui, Yintang, Shenmen, and Sanyinjiao. The second group received sham acupuncture at points unrelated to insomnia treatment.

Patients were unaware of which type of treatment they were receiving, ensuring impartiality of the results. Both groups were treated three times a week for four weeks, totaling 12 sessions, and were followed for three months after the end of treatment.

To evaluate outcomes, the investigators used scientifically validated questionnaires: the Pittsburgh Sleep Quality Index to measure sleep quality, the Hamilton Anxiety Rating Scale to assess anxiety symptoms, and the Hamilton Depression Rating Scale to measure depressive symptoms. In addition, they collected blood samples before and after treatment to measure cortisol and serotonin levels. During the study period, four patients dropped out: one from the true acupuncture group moved to another city for work, and three from the control group were excluded for using psychotropic medications during treatment, resulting in 56 patients who completed the study.

The results clearly demonstrated the superiority of true acupuncture over sham. After treatment, patients who received true acupuncture showed significant improvements in all parameters assessed: sleep quality improved substantially, sleep latency decreased, sleep efficiency increased, and anxiety and depression scores were considerably reduced. More importantly, these improvements remained stable during the three months of follow-up, indicating that the benefits of acupuncture are lasting. In contrast, the group that received sham acupuncture showed only small temporary improvements that disappeared by the end of the observation period.

Laboratory tests revealed that true acupuncture produced a significant reduction in blood cortisol levels and an increase in serotonin levels, suggesting that the technique acts on the biological mechanisms responsible for sleep and mood disorders.

These findings have important implications for both patients and health care professionals. For patients with chronic insomnia accompanied by anxiety and depression, acupuncture represents a safe and effective therapeutic alternative that can be used alone or in combination with other treatments. The fact that the benefits are maintained for at least three months after the end of treatment is particularly encouraging, as it suggests that a relatively short course of acupuncture can provide prolonged symptom relief. For health care professionals, these results provide robust scientific evidence that acupuncture acts through measurable biological mechanisms and is not merely a placebo effect.

Normalization of cortisol and serotonin levels offers a scientific explanation for the benefits observed clinically.

The study has some limitations that should be considered. First, symptom assessment was based primarily on questionnaires completed by the patients themselves, which can introduce subjectivity into the results. Future studies could benefit from the use of polysomnography, an objective examination that monitors sleep throughout the night. Second, chronic insomnia has very varied causes and presentations, and it would be important to determine whether acupuncture is equally effective for all types of insomnia.

Third, although the study investigated important biological markers, other aspects such as changes in brain activity or in the function of different brain regions still need to be explored. Despite these limitations, this research contributes significantly to our understanding of how acupuncture can help people with chronic insomnia and associated mood disorders, offering hope to millions of people who suffer from these interconnected problems.