What does the monoamine hypothesis suggest?
The ‘monoamine hypothesis,’ which suggests a deficiency or imbalances in the monoamine neurotransmitters, such as serotonin, dopamine and norepinephrine, as the cause of depression has been the central topic of depression research for approximately the last 50 years.
What is the evidence that monoamine neurotransmitters might be involved in depression?
Another piece of evidence in support of the Monoamine Hypothesis is that levels of 5-HT, as measured by its metabolites, seem to be correlated with depression. For example, patients who have low levels of a 5-HT metabolite were found to be more likely to have committed suicide.
When was the monoamine hypothesis of depression?
Abstract. In the 1950s, the amine hypothesis of depression was formulated suggesting that depression was associated with a deficiency in the transmission within the monoamine systems, i.e., serotonin, noradrenaline, and dopamine.
What is wrong with the monoamine hypothesis?
However, an important problem of the monoamine hypothesis has been pointed out as follows: it fails to explain the latency of response to antidepressants. In addition, many patients with MDD have remained refractory to currently used antidepressants.
What causes monoamine deficiency?
Causes. Monoamine oxidase A deficiency is caused by mutations in the MAOA gene. This gene provides instructions for making an enzyme called monoamine oxidase A. This enzyme breaks down chemicals called monoamines, including serotonin, epinephrine, and norepinephrine.
Is the monoamine hypothesis wrong?
Conclusion. It is asserted that the monoamine hypothesis, which claims that low synaptic levels of monoamines are a primary etiology of disease, is not a valid primary reference point for understanding chronic electrical dysfunction related to the centrally acting monoamines.
What is a monoamine and how does it work?
Monoamine oxidase inhibitors (MAOIs) are an extremely strong class of antidepressants that treat depression by preventing the breakdown of the brain chemicals serotonin, dopamine, and norepinephrine. This helps them do their work of regulating your mood.
What happens if you have low MAOA?
Mutations in the MAOA gene cause monoamine oxidase A deficiency. This condition affects males almost exclusively and is characterized by mild intellectual disability and behavioral problems, including aggressive and violent outbursts. In some cases, particular foods seem to worsen symptoms of the condition.
What does MAO do in the brain?
An enzyme called monoamine oxidase is involved in removing the neurotransmitters norepinephrine, serotonin and dopamine from the brain. MAOIs prevent this from happening, which makes more of these brain chemicals available to effect changes in both cells and circuits that have been impacted by depression.
How does the MAOA gene cause aggression?
Researchers speculate that an excess of certain neurotransmitters, particularly serotonin and norepinephrine, may impair an affected individual’s ability to control his impulses, leading to aggressive outbursts.
How does the MAOA gene influence behaviour?
Monoamine oxidase (MAO-A) is an enzyme that functions inactivating neurotransmitter amines such as dopamine and serotonin in the brain. In the absence of sufficient levels of MAO, these neurotransmitters accumulate in neurons, which have been correlated with extreme aggressive behaviors.
How does MAOA gene affect aggression?
How does the MAOA gene influence Behaviour?
What causes high MAO?
A number of factors may lead to elevated MAO-A level or activity, including glucocorticoid administration, estrogen depletion and mitochondrial toxicity/dysfunction (Fitzgerald et al, 2007; Ou et al, 2006a; Sacher et al, 2010).
How do you tell if you have MAOA gene?
The Genetics A simple DNA test can be done to find out which single form of MAOA a male has inherited and which two forms a female has inherited. The MAOA gene is located on the X-chromosome. Men inherit only one X chromosome, so they have only one version of MAOA.
What is the monoamine hypothesis of depression?
The monoamine hypothesis of depression states that a depletion of neurotransmitters, known as monoamines, within the brain leads to depression. This depletion may be related to a lack of neurotransmitters or some other fault.
What is an example of a monoamine?
Serotonin and norepinephrine are examples of monoamines. Within the body another monoamine called monoamine oxidase has the effect of breaking down both serotonin and norepinephrine.
How does monoamine oxidase affect the brain?
Within the body another monoamine called monoamine oxidase has the effect of breaking down both serotonin and norepinephrine. Therefore, so the theory goes, by blocking the effect of the monoamine oxidase, the number of monoamines in the brain increases and symptoms of depression are relieved.
Does amitriptyline support the monoamine hypothesis of depression?
Iproniazid as well as other MAO inhibitors were soon shown to be effective in alleviating depression. The clinical and cellular actions of tricyclic antidepressants, such as amitriptyline, were considered to support the monoamine hypothesis of mood disorders.