Attachment to belief can impair thinking and reduce the brain's ability to effective reduce frequency of energy. This is because there's a reduction in left brain hemisphere activity, not so much projection or picking out details, so that instead of going through the enlightenment process such as would happen through consideration or creating the truth and developing morality the left hemisphere relies on the belief and becomes attached to that belief.
Often what can happen is that the left hemisphere will replace the life path with the belief or belief system so that instead of everything being compared with the life path itself, the left hemisphere compares everything to the belief or belief system. Sometimes where necessary the left hemisphere will modify its awareness of the life path so it more closely matches the belief and this can lead to a loss of information and the ability to process energy or information.
This in turn can lead to a loss of awareness and understanding. This is no different to an operating system on a computer losing individual files from the file system. The files no longer exist because they have been deleted, and because the files are now missing the operating system also loses some of its functioning ability and now cannot do certain things.
This is usually a gradual process which often isn't perceived and which can result in a loss of awareness and understanding, a loss of intelligence and functioning ability, a loss of ability to create truth and to develop morality - the so-called moral decline. Moral decline is not usually caused by people choosing to be immoral, they still retain their sense of values and sense of right and wrong, its just that they lose the ability to develop their morality and moral reasoning.
This in turn reduces the brain's ability to effective reduce energy frequency which forces it to have to process energy at a higher frequency and also increases the overall frequency of energy on which the body has to function. When it has to function within a different range of energy frequency the body starts to behave differently and either adapts to the new frequency range or modifies itself further so that it can function within the new frequency range. This can lead to various health issues asnd the triggering of various genetic predispositions to health issues.
Where the beliefs are imposed in a system or through social attitudes this is what leads to the so-called 'dumbing down' and you end up having to live in a system which forces you to be less aware and even more stupid.
Belief attachments are an inherent feature of addiction, social stigma and social exclusion and can be found commonly in many types of religious and political thinking. Authoritarianism is a prime example of how an attachment to a belief system can override the normal enlightenment process.