I believe that mental health can be optimized without the help of a psychologist. The reason I think so is that psychology only studies the human mind, and as such does not understand human behavior. As an example, take “psychology”, which is being defined by its methods: it supposedly seeks to analyze how the brain works, but this can never reach true understanding because it relies on observation alone rather than experimentation (the difference between pure theory and scientific theory). When psychological experiments are done they do not have control groups or even use statistical analysis to draw their conclusions (i.e., they rely on anecdotal evidence), making them statistically invalidated.
The human mind is not an object that can be fully understood in isolation from the environment, for it does not exist separate from the rest of the world. Mental health cannot be optimized because to do so one would have to define mental health as a state of happiness based on what individuals find pleasurable and then optimize their external environment accordingly; however, there are many things in life that are considered pleasurable by some people but painful by others (e.g., eating hot chili peppers), and even if someone did happen to agree with most people about what was pleasurable or painful, they could still disagree about how important each thing was – for example, I may enjoy eating pizza while my friend enjoys drinking water; he may think that water is more valuable than pizza while I believe otherwise.
In addition, the human mind is a complex system in a dynamic environment and can never be optimized for anyone part of its functionality because it is always going through changes (e.g., I may learn how to play piano, which improves my motor skills but takes away time that I would otherwise have spent playing chess or reading books). Therefore mental health cannot be defined as an optimal state for all functions of the human mind.
If it is defined as a state of happiness, then how can one define happiness? In psychology “happiness” is defined subjectively by the individual based on their own experiences and preferences; however, not everyone has the same experience or preference (e.g., some people are happy while others are unhappy).
Therefore, optimizing mental health is not possible without a clear definition of happiness.