My answer to Can dissociation be permanent or is it only episodic?
Answer by Carlo Carandang:
If you are talking about dissociation in the context of depersonalization or derealization, then this is something that some people experience when they have anxiety. In this context, derealization is an attempt to dissociate from the very uncomfortable feelings, emotional distress, maladaptive thoughts, and physical symptoms of anxiety. I explain this in more detail in another Quora Q&A: How can I free myself from a mix of social anxiety and severe long term depersonalization?
Therefore, dissociation associated with anxiety is a maladaptive coping skill, that actually serves to maintain the negative cycle of anxiety. Dissociation from anxiety is therefore episodic and temporary, as long as the anxiety is treated by learning more adaptive coping skills, relaxation techniques, and possible medication treatment for more severe anxiety symptoms.
For more severe dissociation, Mike King gives an excellent overview of Dissociative Disorders.