Final answer:
The nursing diagnosis reflecting the intrapersonal theory of OCD etiology is 'Ineffective coping R /T punitive superego,' which aligns with internal psychological conflicts.
Step-by-step explanation:
The nursing diagnosis that reflects the intrapersonal theory of the etiology of obsessive-compulsive disorder (OCD) is Ineffective coping R /T punitive superego. The intrapersonal theory suggests that OCD can originate within the individual, often related to internal conflicts and psychological dynamics, such as battles between the ego, id, and superego as described by psychodynamic theories. The reference to a 'punitive superego' fits with this concept, as it implies a harsh, overly critical self-assessment that can lead to rituals and behaviors associated with OCD in an effort to manage the inner conflict. Alteration in serotonin and classic conditioning are more related to biological and learned aspects of OCD, respectively, while active avoidance could pertain to several psychological disorders.