Final answer:
One key limitation of defining psychopathology by deviation from ideal mental health is the subjective nature of what constitutes 'ideal' mental health, which varies between cultures and can lead to overpathologization.
Step-by-step explanation:
One limitation of using deviation from ideal mental health as a definition of psychopathology is that the concept of ideal mental health is very subjective and culturally relative. Different societies have various norms and values, which means that behaviors considered signs of maladjustment in one culture may be deemed perfectly healthy in another. Additionally, some criteria for ideal mental health, such as 'self-actualization' or 'resilience to stress', can be unrealistic for many individuals facing systemic inequalities or chronic life stressors, thus pathologizing individuals in challenging circumstances who might otherwise be functioning adequately. Hence, this definition can lead to overpathologization and potentially ignore the impact of socio-cultural factors on individual mental health.