Neurotransmitters & Mental Disorders PDF

Neurotransmitters & Mental Disorders Problems With Neurotransmitters As with many of the body's processes, things can sometimes go awry. It is perhaps not surprising that a system as vast and complex as the human nervous system would be susceptible to problems. A few of the things that might go w...

Neurotransmitters & Mental Disorders Problems With Neurotransmitters As with many of the body's processes, things can sometimes go awry. It is perhaps not surprising that a system as vast and complex as the human nervous system would be susceptible to problems. A few of the things that might go wrong include: Neurons might not manufacture enough of a particular neurotransmitter Neurotransmitters may be reabsorbed too quickly Too many neurotransmitters may be deactivated by enzymes Too much of a particular neurotransmitter may be released When neurotransmitters are affected by disease or drugs, there can be a number of different adverse effects on the body. Diseases such as Alzheimer's, epilepsy, and Parkinson's are associated with deficits in certain neurotransmitters. Certain neurotransmitters play an important role in the brain by influencing mood, which is why they are sometimes described as "feel-good" chemicals. Five important neurotransmitters include dopamine, serotonin, oxytocin, norepinephrine, and endorphins. Health professionals recognize the role that neurotransmitters can play in mental health conditions, which is why medications that influence the actions of the body's chemical messengers are often prescribed to help treat a variety of psychiatric conditions. For example: dopamine is associated with such things as addiction and schizophrenia. Serotonin plays a role in mood disorders, including depression and OCD. Dopamine, GABA, serotonin, and norepinephrine are linked to anxiety disorders. Drugs, such as SSRIs, may be prescribed by physicians and psychiatrists to help treat symptoms of depression or anxiety. Not enough acetylcholine can lead to the loss of memory that’s seen in Alzheimer’s disease. Too much serotonin is possibly associated with autism spectrum disorders. An increase in activity of glutamate or reduced activity of GABA can result in sudden, high-frequency firing of local neurons in your brain, which can cause seizures.  Too much norepinephrine and dopamine activity and abnormal glutamate transmission contribute to mania. Drugs That Influence Neurotransmitters Perhaps the greatest practical application for the discovery and detailed understanding of how neurotransmitters function has been the development of drugs that impact chemical transmission. These drugs are capable of changing the effects of neurotransmitters, which can alleviate the symptoms of some diseases. Agonists vs. antagonists: Some drugs are known as agonists and function by increasing the effects of specific neurotransmitters. Other drugs and referred to as antagonists and act to block the effects of neurotransmission. Direct vs. indirect effects: These neuro-acting drugs can be further broken down based on whether they have a direct or indirect effect. Those that have a direct effect work by mimicking the neurotransmitters because they are very similar in chemical structure. Those that have an indirect impact work by acting on the synaptic receptors. Drugs that can influence neurotransmission include medications used to treat illnesses including depression and anxiety, such as selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, and benzodiazepines. For example, SSRIs such as Prozac (fluoxetine) and Paxil (paroxetine) block serotonin from being absorbed by nerve cells, increasing serotonin levels in the brain. Cholinesterase inhibitors such as Aricept (donepezil) block enzymes that break down acetylcholine, which can help improve cognitive functioning in people who have Alzheimer's disease. Illicit drugs such as heroin, cocaine, and marijuana also affect neurotransmission. Heroin acts as a direct-acting agonist, mimicking the brain's natural opioids enough to stimulate their associated receptors. Cocaine is an example of an indirect-acting drug that influences the transmission of dopamine.