No, it is not normal to become a psychopath or develop any specific personality disorder solely due to becoming an atheist or due to changes in one's beliefs. Being an atheist simply means that a person does not believe in the existence of deities or gods, and it does not necessarily have any direct correlation with personality traits or mental health.
Personality disorders, including psychopathy, are complex conditions that have multifactorial causes. They result from a combination of genetic, environmental, and developmental factors. Psychopathy is a specific personality disorder characterized by a lack of empathy, remorse, and a tendency toward manipulative and antisocial behavior. It is relatively rare in the general population.
Becoming an atheist, like any change in belief systems, may bring about various psychological and emotional adjustments. Some individuals might experience a shift in their worldview and ethics, but this doesn't automatically lead to the development of a personality disorder.
It's crucial to recognize that most atheists are not psychopaths or have any personality disorders. The majority of atheists, like believers of any other ideology, are ordinary people with a wide range of personalities and moral values.
If someone experiences significant changes in behavior, emotions, or personality traits, it's essential to consider various factors and consult with mental health professionals if needed. Remember, mental health issues are complex and require proper assessment and treatment by trained specialists.