PHPathophysiology of Depression
By: Raizen
The pathophysiology of many diseases, including psychiatric disorders such as depression, can be viewed from several different levels of organization. At the level of the synapse, depression appears to be accompanied by changes in neurotransmitters such as norepinephrine, 5-HT (related to serotonin), and dopamine. On the level of neural pathways, glutamergic and acetycholinergic connects are diminished. The activity of the immune system, especially in response to stress levels, changes during depression. Endocrine processes, such as the hypothalamus-pituitary-adrenal (HPA) axis, are disturbed as well. Finally, the balance in activity between areas of the brain becomes abnormal in the person with major depression (Murck, 2013).
In the synapse, the tiny physical gap between one neuron and another, neurotransmitters move back and forth to ferry excitatory and inhibitory signals along the neural pathways. Biochemical studies of depression have revealed decreases in acetycholinergic and glutamergic activity in the synapse. Other research has shown a functional deficiency in the monoaminergic neurotransmitters norepinephrine, 5-HT, and dopamine. It has been suggested that this represents a depletion in neurotransmitters due to overproduction of the enzymes that degrade them, but healthy volunteers who were depleted of neurotransmitters did not become depressed (Bondy, 2002). However, in depressed individuals the depleted neurotransmitters may be accompanied by changes in their transporters and receptors.
The hypothalamus is a deep brain structure that is the initiator for several pituitary-controlled endocrine processes such as the hypothalamus-pituitary-adrenal (HPA) axis (stress hormones) and the hypothalamus-pituitary-thyroid (HPT) axis (metabolism). Endocrine pathways such as these are often abnormal in the presence of depression; in fact, extended periods of stress and decreased levels of thyroid hormones are associated with depression (Xin & Pang, 2015). Excess stress hormones are known to alter the function of the frontal cortex, the hippocampus, amygdala, and basal ganglia – brain structures that are related to mood and mood disorders.
There are a number of other chemical processes in the brain that are believed to affect or to trigger major depression: neuroimmune chemicals such as cytokines, neurotrophic factors, and other modulating factors such as vasopressin, neuropeptide Y, and excitatory amino acids. (Northoff, 2013)
Source of DeepWebPH
By: Raizen
The pathophysiology of many diseases, including psychiatric disorders such as depression, can be viewed from several different levels of organization. At the level of the synapse, depression appears to be accompanied by changes in neurotransmitters such as norepinephrine, 5-HT (related to serotonin), and dopamine. On the level of neural pathways, glutamergic and acetycholinergic connects are diminished. The activity of the immune system, especially in response to stress levels, changes during depression. Endocrine processes, such as the hypothalamus-pituitary-adrenal (HPA) axis, are disturbed as well. Finally, the balance in activity between areas of the brain becomes abnormal in the person with major depression (Murck, 2013).
In the synapse, the tiny physical gap between one neuron and another, neurotransmitters move back and forth to ferry excitatory and inhibitory signals along the neural pathways. Biochemical studies of depression have revealed decreases in acetycholinergic and glutamergic activity in the synapse. Other research has shown a functional deficiency in the monoaminergic neurotransmitters norepinephrine, 5-HT, and dopamine. It has been suggested that this represents a depletion in neurotransmitters due to overproduction of the enzymes that degrade them, but healthy volunteers who were depleted of neurotransmitters did not become depressed (Bondy, 2002). However, in depressed individuals the depleted neurotransmitters may be accompanied by changes in their transporters and receptors.
The hypothalamus is a deep brain structure that is the initiator for several pituitary-controlled endocrine processes such as the hypothalamus-pituitary-adrenal (HPA) axis (stress hormones) and the hypothalamus-pituitary-thyroid (HPT) axis (metabolism). Endocrine pathways such as these are often abnormal in the presence of depression; in fact, extended periods of stress and decreased levels of thyroid hormones are associated with depression (Xin & Pang, 2015). Excess stress hormones are known to alter the function of the frontal cortex, the hippocampus, amygdala, and basal ganglia – brain structures that are related to mood and mood disorders.
There are a number of other chemical processes in the brain that are believed to affect or to trigger major depression: neuroimmune chemicals such as cytokines, neurotrophic factors, and other modulating factors such as vasopressin, neuropeptide Y, and excitatory amino acids. (Northoff, 2013)
Source of DeepWebPH
