By Lauren DeSouza- Master of Public Health, Simon Fraser Public Research University – Canada
Staff Research and Content Writer
© Copyright – SUD RECOVERY CENTERS– A Division of Genesis Behavioral Services, Inc.,
Milwaukee, Wisconsin – November 2023 – All rights reserved.
In recent years, there has been growing interest in how inflammation in the body might be linked to depression. Research is starting to show that inflammation can contribute to depression and vice-versa, through chronic stress, the immune system, the endocrine system, and more. This new evidence has led to growing research into the potential for using anti-inflammatory drugs to treat depression. Statins, primarily known for their cholesterol-lowering effects, have been studied for their potential anti-inflammatory properties. These properties may contribute to their impact on depressive symptoms.
There is a debate on whether statins can effectively treat depression. Although some small clinical trials have reported positive anti-depressive effects, real-world studies have suggested that statins may worsen symptoms of anxiety and depression. To resolve this controversy, a new study comprehensively reviewed the available evidence regarding the efficacy of using statins for treating major depressive disorder (MDD).
What is the relationship between inflammation and depression?
Studies have consistently shown elevated levels of inflammatory markers, such as cytokines (small proteins involved in cell signaling during the immune response), in individuals with depression. Inflammation can influence the balance of neurotransmitters, such as serotonin and dopamine, which affect mood regulation. Neuroinflammation (inflammation in the brain) may play an especially prominent role in depression. The immune cells in the brains of people with depression have been observed not to function correctly, suggesting a link between neuroinflammation and mood disorders.
Image via Freepik
Anti-inflammatory medications such as statins may have antidepressant side effects through various pathological mechanisms. These include:
- Anti-inflammation: Suppressing the production of inflammatory molecules such as cytokines
- Immune regulation: Regulating immune cell function, which reduces inflammation
- Neuroprotection: Protecting neurons from inflammation-related damage
- Neurotrophic: Influencing neurotransmitter systems, which play a role in mood management
- Antioxidant: Reducing oxidative stress in cells, which is linked to inflammation.
What did this study do?
This study was a systematic review and meta-analysis. This means that researchers looked at all studies that aimed to answer the question they were interested in. The research question in this study was, “What is the effect of statin on depressive mood and inflammation status among patients with major depressive disorder (MDD)?” They specifically looked for randomized controlled trials (RCTs) as these studies use the most rigorous methods to test the effectiveness of a drug, either against a placebo or another treatment.
In the included studies, patients were given either a combination of statin with a selective serotonin reuptake inhibitor (SSRI), a standard treatment for MDD, or given just the SSRI. for a study to be included in the review, its participants had to be given either an SSRI or an SSRI plus statin for a minimum of 6 weeks. In total, 6 studies were included in the review.
The researchers were primarily interested in whether the treatment with statin reduced patients’ depressive symptoms, which were measured with the Hamilton Depression Rating Scale. They also wanted to understand how statin affected patients’ response to treatment and how many relapsed into major depression during treatment with statin. Finally, they looked at how many patients in each study experienced adverse effects from statin and what these effects were.
What were the results?
Compared with using SSRIs alone, treatment with statin plus SSRIs was associated with significantly decreased depressive symptoms among patients with MDD. When used as an add-on to SSRIs, treatment with statin safely and effectively improved the severity of depressed mood and lowered inflammation. In addition, patients treated with stain had a similar rate of relapse and similar response to treatment as using SSRIs alone, suggesting that these treatments are comparably effective and well-tolerated.
The positive effects of statin treatment were most prominent in studies with mid- to long-term follow-up periods. However, most of the included studies had short follow-up periods. The authors note that more studies with longer follow-ups are needed to ascertain the risks and benefits of statin treatment for MDD. Large RCTs are warranted to confirm the value of statin therapy in patients with MDD, especially among those with diseases of the cardiovascular system and nervous system.
Image via Freepik
What are the key takeaways?
- There is a growing awareness of the link between inflammation and depression.
- Researchers are exploring the use of anti-inflammatory medications as an adjunct treatment for depression.
- The use of statin, an anti-inflammatory medication, is controversial in the treatment of depression.
- A systematic review and meta-analysis of existing literature found a net positive effect of treatment with statins in combination with SSRIs on depressive mood.
Xue Xiao, Hu Deng, Peng Li, Jifei Sun, Jing Tian. Statin for mood and inflammation among adult patients with major depressive disorder: an updated meta-analysis. Front. Psychiatry, 15 November 2023. Sec. Psychological Therapy and Psychosomatics
Volume 14 – 2023 | https://doi.org/10.3389/fpsyt.2023.1203444
How did this study work?
This study specifically looked at patients with depression who also suffered from insomnia. The researchers were interested in seeing whether electroacupuncture was a safe and effective treatment for patients with comorbid mental health and sleep disorders.
This study was a randomized clinical trial that compared groups of patients receiving the target intervention, electroacupuncture, with sham acupuncture and with standard care (no intervention). Standard care included guidance from a doctor to get regular exercise, eat a healthy diet, and manage their stress levels during the trial, as well as continuing to take any prescribed medications for sleep or depression.
This was the longest study to date to look at acupuncture to treat insomnia. Patients received electroacupuncture three times a week for eight weeks, for a total of 24 sessions. This was followed by a 24-week observational period to see how long the benefits of treatment would last, for a total study duration of 32 weeks.
The acupuncture administered in this study targeted the Governor vessel. According to the researchers, the Governor vessel “governs all yang meridians and helps regulate the balance of yin-yang in the body, which is closely related to brain functions”. Targeting this vessel can help to calm nerves and relax patients, improving their symptoms of depression.
What were the results?
Patients who received electroacupuncture experienced significant improvements to their sleep. Their sleep quality improved, they slept for longer, and they woke up fewer times during the night. These improvements persisted for the duration of the study, meaning that the effects of the acupuncture lasted for weeks after it had been administered.
Electroacupuncture also helped to improve symptoms of mental health disorders. Patients experienced reductions in the severity of insomnia, symptoms of depression, and symptoms of anxiety.
With regard to safety, there were no severe adverse events reported during the trial. The researchers conclude that electroacupuncture may be a safe treatment for patients with comorbid depression and insomnia.
What are the takeaways?
- Electroacupuncture is a safe and effective treatment to help patients with depression-related insomnia improve their quality of sleep.
- The benefits of electroacupuncture on sleep quality continue for over 20 weeks after treatment.
- Electroacupuncture can also help patients improve symptoms of depression and anxiety.
Yin X, Li W, Liang T, et al. Effect of Electroacupuncture on Insomnia in Patients With Depression: A Randomized Clinical Trial. JAMA Netw Open. 2022;5(7):e2220563.