if you mean academic as in a critic then it's best to use a few quotes (maybe two) from different critical readings to support your response
critic's quote example:
"Made on the eve of the dropping of the atomic bomb, Citizen Kane is perhaps a new film art for a new film era and one whose lead more and more film directors may take as they realize that fewer and fewer people in this, the age of narcissism, are reflective or self critical." quoted by Bert Cardullo
Using quotes such as this, you can also contrast that critical reading with your understanding of Citizen Kane in your essay.