In neurophysiology, long-term depression is an activity-dependent reduction in the efficacy of neuronal synapses lasting hours or longer following a long patterned stimulus. LTD occurs in many areas of the CNS with varying mechanisms depending upon brain region and developmental progress.
Long-term depression (LTD) is the opposite of LTP, and is characterized by a decrease in postsynaptic strength. This happens by dephosphorylation of AMPA receptors and the facilitation of their movement away from the synaptic junction.
Long-term depression (LTD) encompasses a family of synaptic plasticity mechanisms that can be triggered by the synaptic or pharmacological activation of glutamate receptors — in particular NMDARs (N-methyl-D-aspartate receptors) and metabotropic glutamate receptors (mGluRs) — or receptors for other neurotransmitters.
Untreated clinical depression is a serious problem. Untreated depression increases the chance of risky behaviors such as drug or alcohol addiction. It also can ruin relationships, cause problems at work, and make it difficult to overcome serious illnesses.
Persistent depressive disorder (PDD) is a mild to moderate chronic depression. It involves a sad or dark mood most of the day, on most days, for two years or more. PDD is common and can happen to anyone at any age.
Each person's recovery is different. Some recover in a few weeks or months. But for others, depression is a long-term illness. In about 20% to 30% of people who have an episode of depression, the symptoms don't entirely go away.
There's growing evidence that several parts of the brain shrink in people with depression. Specifically, these areas lose gray matter volume (GMV). That's tissue with a lot of brain cells. GMV loss seems to be higher in people who have regular or ongoing depression with serious symptoms.
Psychological counseling (psychotherapy) by a psychiatrist, psychologist or other mental health professional can be very effective. For many people, psychotherapy combined with medication works best. It can help identify underlying concerns that may be adding to your depression.
You may be diagnosed with mild, moderate or severe depression. Your mental health professional may diagnose you with depression if these symptoms: happen most days. last for at least two weeks.
A depression not only makes a person feel sad and dejected – it can also damage the brain permanently, so the person has difficulties remembering and concentrating once the disease is over. Up to 20 percent of depression patients never make a full recovery.
Long-term depression (LTD) is such a process. In the late 1970s, LTD was found to occur at the synapses between the Schaffer collaterals and the CA1 pyramidal cells in the hippocampus.
Depression Causes Physical Symptoms
Chronic fatigue. Decreased interest in sex. Decreased appetite. Insomnia, lack of deep sleep, or oversleeping.
An estimated 3.8% of the population experience depression, including 5% of adults (4% among men and 6% among women), and 5.7% of adults older than 60 years. Approximately 280 million people in the world have depression (1).
Dysthymia (Persistent Depressive Disorder) Dysthymia, also known as persistent depressive disorder, is a long-term form of depression that lasts for years and can interfere with daily life, work, and relationships. People with dysthymia often find it difficult to be happy even on typically joyous occasions.
Suicidal ideation or self-harm
Thoughts of suicide, self-harm, or death is often the most serious stage and symptom of depression.
Feelings of sadness, tearfulness, emptiness or hopelessness. Angry outbursts, irritability or frustration, even over small matters. Loss of interest or pleasure in most or all normal activities, such as sex, hobbies or sports. Sleep disturbances, including insomnia or sleeping too much.
Depression is a common mental disorder. Globally, it is estimated that 5% of adults suffer from the disorder. It is characterized by persistent sadness and a lack of interest or pleasure in previously rewarding or enjoyable activities. It can also disturb sleep and appetite.
For some people, depression might only be episodic and overcome within a matter of weeks or months. However, for others diagnosed with major depression , the condition could persist for years, affecting their lifestyle and quality of life.
It's often said that depression results from a chemical imbalance, but that figure of speech doesn't capture how complex the disease is. Research suggests that depression doesn't spring from simply having too much or too little of certain brain chemicals.
Depression on its own does not cause death but the behaviors associated with depressed individuals increases the risk of chronic and deadly diseases. These diseases may include coronary heart disease, obesity, diabetes, lung disease, osteoporosis, and cancer.
For example, depression is more common among women than men. The median age of onset for depression is 32 years, meaning that half of people who will ever have a depressive episode will have had their first episode by this age.