The Brain reacts to cheating by altering the concentration of some of the major biochemical compounds related to regulation of mood. Among others, these substances include serotonin, dopamine and endorphins. Brain reacts to cheating in same manner as the brain of a drug addict reacts to sudden deprivation of drug. When your husband or wife is cheating on you or is having an affair, you are suddenly deprived of your regular "drug", which in this case is the love and attachment of your spouse.
After cheating or an affair has occurred, you can no longer believe the love of your husband or wife towards you is as strong as it used to be. You have been robbed something very valuable and as a result of this you are experiencing similar withdrawal symptoms as drug addicts experience when drug is no longer available to them. You may experience anxiety, depression, deep sadness, hopelessness, insecurity, mental and even physical pain. These are natural biological responses to threatening possibility that you might lose your spouse.
There are ways to speed up the process of getting over feelings of anxiety and depression due to cheating, mistrust, insecurity and betrayal in a relationship. Understanding the evolutionary and biological basis of your emotions will help you to control your emotions better and recover faster after tragedies in life such as finding out about cheating or an affair.
The Human brain is amazingly complicated device. It is possible to teach the brain to react in different ways in certain situations by using simple methods, in similar fashion as it is possible to teach the brain to get rid of certain kinds of phobias or to block the sensation of pain. Brain is much more flexible than one would think. This gives hope to those of us who are struggling to get over painful memories related to cheating.
The key thing is to understand that you hold the power over your mind, not other way around. Do not let sadness and negative thoughts due to the memory of cheating drag you down. if you only think about the matters related to cheating, the neuronal networks in your brain related to the event of cheating or an affair will be strengthened. As a result of this, negative thoughts related to the memory of cheating are constantly occupying your mind even if you do not want them to. A negative feedback loop has been formed and if you do not do anything to interrupt the loop, it keeps strengthening itself and you may become seriously depressed due to cheating or an affair of your husband or wife.