The Kraepelinian dichotomy in terms of suicidal behaviour.

The Kraepelinian dichotomy sees schizophrenia and bipolar disorder as two distinctly separate diseases each with its own pathogenesis and disease process. This study looks at the difference between patients with schizophrenia and bipolar disorder in terms of suicidal behaviour. Both schizophrenia and bipolar disorder have been identified as significant risk factors for suicide, while bipolar and major depressive disorder appear to be the greatest diagnostic indicators. This study also aims to look at any differences in suicidal behaviour between the two major classes of bipolar disorder (bipolar I and bipolar II) to possibly determine how distinct these two conditions are in this respect. As expected, this study found that patients with a diagnosis of bipolar disorder were significantly more likely (OR=4.79) to have a history of suicidal behaviour than patients with a diagnosis of schizophrenia. Neither bipolar I nor bipolar II patients were significantly more likely to have a history of suicidal behaviour. However, this study yielded a weak association between bipolar II patients and suicidal behaviour (OR=1.83) compared to bipolar I patients, which may have been more significant under different circumstances such as a greater sample size.