News: Cannabidiol (CBD) Consideration in Parkinson Disease
The results showed that administration of 300 mg/day of CBD improved clinical participants mobility, communication, and emotional state.
A Meta-analysis Suggests that Moderate-intensity Physical Activity Reduces the Risk of Developing Depression
Disclaimer: Not medical or professional advice. Always seek the advice of your physician.
Researchers synthesized findings from 191 130 participants with depression in order to assess the correlation between the incidence of depression and the intensity of physical activity.
The author of an article published in JAMA Psychiatry claims that there is a 30% lower risk of depression for people participating in moderate-intensity physical activity compared with inactive individuals. One example of moderate-intensity activities is 2.5 hours of brisk walking per day.
Why is Depression Dangerous?
Depression is a mental disorder. People with depression can experience a variety of symptoms such as low mood, reduced ability to enjoy life, severe apathy, pessimism, and limited physical strength. And the most disturbing sign is suicidal ideation.
Depressed people often fail to maintain fulfilling relationships with their loved ones, do household chores, and look after themselves. Besides, they are at risk of suffering from poor academic and work performance since depression often negatively impacts cognitive abilities and brain function.
According to the monoamine hypothesis, the leading theory of depression, the disease is associated with a disruption in neurotransmitter function. Neurotransmitters are substances that help carry signals between brain cells. For example, serotonin, dopamine, and norepinephrine - a group of neurotransmitters collectively called monoamines.
Depression is also linked to changes in several parts of the brain: the hippocampus (responsible for memory formation and emotion regulation), the prefrontal cortex (in charge of processing information from the hippocampus), and the amygdala (involved in regulating emotions, including fear-related responses).
Researchers are conducting a variety of clinical trials to find new ways to prevent the development of depression and relieve the presenting symptoms. Recent studies found a positive effect of taking omega-3 on the improvement of depression, as well as lower depression scores in walnut consumers.
What is the Link Between Physical Activity and Depression?
Multiple studies have confirmed various health and cognitive benefits of being physically active. Australian doctors discovered that physical activity among people with sleep problems could decrease their risk of mortality. Another study conducted by British scientists revealed a direct relationship between children’s physical activity and emotional regulation, which also had beneficial influences on academic performance.
The fact is that the brain and the body are closely linked and affect each other. Thus, brain neurochemistry is directly dependent on how we treat our bodies. But despite many studies confirming the positive impact of exercise on mental health, the mechanism underpinning the association between levels of physical activity and depression were not established.
However, a team of researchers from Australia, Brazil, the UK, Poland, Singapore, and Finland, led by Matthew Pearce from the University of Cambridge, decided to conduct a meta-analysis based on articles that described the level of physical activity in patients with depressive symptoms and major depressive disorder.
The selection criteria for 19 175 articles were based on the sample size of more than 3000 participants, reference to the level of physical activity of the participants, as well as depression risk assessment. The final analysis included 15 articles comprising 191 130 people aged 18 and over.
The authors of the meta-analysis converted the given levels of physical activity into marginal metabolic equivalent task (mMET) hours per week. For example, a range of 0.5-2.0 mMETs corresponds to low-intensity exercises (light household chores) and a score of 7.0 mMET to vigorous physical activity.
The results of the meta-analysis showed an inverse curvilinear relationship between the level of physical activity and the stages of major depressive disorder or depressive symptoms.
The relationship between the level of physical activity and the development of major depressive disorder and symptoms of severe depression.
Matthew Pearce et al. / JAMA Psychiatry, 2015
This implies that even light physical activity (approximately half the amount of physical activity recommended by the World Health Organization) has a profound effect on mental health. Adults with a score of 4.4 mMET were 18% less likely to develop depression compared with individuals reporting no physical activity. People who met the recommended level of physical activity (8.8 mMET) had a 25% lower risk of the condition. An increase in the intensity above normal has not shown significant health benefits.
Through research, the authors concluded that the recommended dose of physical activity (according to WHO) equivalent to 2.5 hours of brisk walking per week could reduce the risk of developing depression by 25%.