Moods naturally fluctuate and every one experience highs and lows in their lives. But in some cases, changes in mood can become long-lasting and debilitating and can impair someone’s ability to hold down a job or sustaining meaningful relationships. It is estimated that around 10 percent of people will at some point in their lives suffer from depression a mood disorder characterized by several symptoms. A complete guide and description we will briefly discuss Depression and Treatments for depression so Let’s get started.
Symptoms of Depression
First of all, we should know what are the major symptoms of depression. Below are some visible symptoms of depression.
- Feeling sad.
- Lack of Motivation.
- Excessively tired.
- Losing interest in once pleasurable activities known as anhedonia.
- Many people with depression suffer from anxiety.
- Less social interaction.
Effects of Depression
Neuroimaging studies reveal that many brain circuits that normally regulated moods are dysregulated in depression. Located deep within the brain the amygdala processes highly salient stimuli such as rewards and potential threats, in depression, the amygdala is overactive and responds excessively to negative events, in turn, the amygdala connects to a set of brain regions that hone the physiological and behavioral response to emotional stimuli. These areas include the medial prefrontal cortex, the nucleus accumbens, the hippocampus, and the insula.
The hippocampus is involved in memory formation and along with the prefrontal cortex is particularly vulnerable to the effects of stress. Depressed people are more susceptible to stress which can cause physical changes in the brain including atrophy of the hippocampus. This and other changes in depressed people may cause inappropriate responses to emotional events.
The medial prefrontal cortex is involved in regulating how strongly we react to emotional stimuli.
Treatments for Depression
Common treatments for depression are;
- Treatments such as antidepressant drugs.
- Cognitive behavioral therapy.
- And electroconvulsive therapy.
These affect the structure and function of the hippocampus, prefrontal cortex, amygdala and other brain regions.
Animal models such as mice are critical in helping us understand the cellular molecular changes underlying depression and better treatments.
It is impossible to know if a mouse is depressed. My subject is to chronic stress show some symptoms similar to depressed human such as anxiety-like behavior, less social interaction, and lack of interest in normally pleasurable activities.
Complete Study on Treatments for Depression
While not all human depression is triggered by stress these models may still shed light on the biology of depression and they are the closest scientist can get while studying mice. As with human’s chronic stress in mice can lead the atrophy of the hippocampus and prefrontal cortex. Mouse studies have also shown altered neuronal plasticity in various brain regions including the hippocampus, prefrontal cortex, amygdala, and nucleus accumbens.
In the healthy hippocampus, an experience can lead to changes in the connections between neurons resulting in learning. These changes are referred to as plasticity. Chronic stress can reduce this plasticity.
The healthy brain also continues to produce new neurons in one part of the hippocampus. These new neurons slowly mature and integrate into the circuitry where they have a strong effect on the hippocampal activity and behavior. These neurons are also affected by stress, they reduce in number in stressed brains. These effects may result the reduced levels of neurotrophins(Protein that increases neuronal growth and plasticity). Reduced plasticity may stop the hippocampus from being able to properly regulate the stress response which may lead to a vicious cycle where stress perpetuates the more stress.
The hippocampus is particularly affected but there can be reductions in plasticity elsewhere in the brain and together with these changes could contribute to the other symptoms of depression ham head onea. Whether these cellular changes in mice are involved in human depression remains unclear.
Antidepressants Drugs for Depression
Most antidepressant available today rapidly increase the amount of neurotransmitters serotonin and/or norepinephrine in the synapse. However, improvements in symptoms in patients and mice usually do not occur until weeks after starting the treatment. While these delays are not fully understood prolonged treatment with the antidepressant can over time act to reverse some of the changes induced by increasing stress. These are neurotrophins expressions and rebooting hippocampus plasticity.
Non-chemical treatments for depression including electroconvulsive shocks also promotes hippocampal plasticity in mice.
Antidepressant treatment can also reverse the stress-induced changes in other areas of the brain including prefrontal cortex and rewards circuitry. Different treatments may target the different regions to improve symptoms.
The ketamine is a drug that has rapid antidepressant effects in patients with depression as well as in rodent models with effects lasting for days. The mechanism behind this is an area of active research. Ketamine blocks a type of synaptic transmission leading to activation of a number of signaling pathways an increasing neurotrophins expression. These molecular changes result in increased plasticity in the prefrontal cortex and hippocampus and likely contribute to ketamine behavioral effects.
By studying the changes in the brain caused by chronic stress and how antidepressants like ketamine work to reverse them, researchers may find new targets for treatment or new drugs that could act more quickly more specifically or more effectively than currently available treatments.
Thanks for sparing your precious time to read this important information. Keep visiting healthnmedicare for more. Credits to Nature Neuroscience