How to Write a Comparative Critical Essay on a Novel (Brief Example)

Introduction
The American literary critic Robert Scholes described the story of Esther Greenwood in The Bell Jar as “…how she tried to die, and how they stuck her together with glue.” (make sure to reference critic's opinions on chosen novels and expand on them) This comment reflects the simplistic approach towards recovery from mental illness during 1950s America, the decade in which the book is set. It is also relevant to Janice Galloway’s modern day novel The Trick is to Keep Breathing, which is also written from the perspective of a young female struggling with the difficulties of everyday life due to the onset of mental ill health (highlight the way in which you are going to compare the novels). Although both books are drastically diverse in structure, narrative style and their approach to the subject (this states what is going to be contrasted in the following essay), they have a number of similarities. These include the narrators’ attitude toward the opposite sex, their difficulty in forming meaningful relationships and the poor quality of mental health treatment on offer (This states what you are going to compare. It is key to lead the reader by their hand through the essay and it can help keep you on track if you clearly know what you are going to do). Both authors effectively address the fear and confusion of mental deterioration and encourage the reader to engage and empathise with the characters’ circumstance while exploring significant underlying themes.  
Body Paragraphs (addressing the points you mentioned in the intro)
Joy’s story is told in the form of a day-to-day account, almost like a diary (make a statement). As highlighted in a review by The List (mention outside sources as much as you can as it shows you've researched your essay), Galloway approaches this from an unorthodox angle using unusual typography to convey her blurred thinking and disturbed mental state (explain your statement (why you think this)). This allows the reader to experience her mental disorder through structure as well as narrative (the effect it has on the reader). The following extract demonstrates the way Joy’s mind works and how the structure allows the reader to share her suffering: (use a quote which backs up your statement)
Conclusion
In conclusion (let your reader know exactly what's happening), both texts are very effective in conveying what it’s like to suffer from mental illness and the pressures that can lead to it. They both explore how society’s attitude to women restricts the main characters, causing them to struggle to build healthy relationships with the opposite sex. They also clearly show how mental illness isolates the sufferer from other people (why the texts are successful - how they answer the provided question successfully or unsuccessfully). However (which text you find more effective and why), I believe that The Trick is to Keep Breathing presents the reader with a more engaging and authentic account of someone suffering from a serious mental condition (statement). Galloway’s experimental use of structure and stream of consciousness narrative style enables the reader to experience Joy’s distressing symptoms almost thought by thought, thus elevating our understanding of what sufferers have to live with. (evidence to back it up)