Although the Kraepelinian classification paradigm is widely used, observations of overlapping boundaries between the symptoms associated with bipolar disor- der and schizophrenia are beginning to challenge this dichotomy. The objective of this research was to explore the symptoms of individuals diagnosed with schizo- phrenia and with bipolar mood disorder in order to de- termine the frequency of symptom overlap. One hun- dred patients of a psychiatry ward were divided into two main groups based on their diagnosis—schizo- phrenia or bipolar mood disorder. Chi-square analy- ses were used to determine whether the symptoms mea- sured in this study differed between individuals di- agnosed with schizophrenia and those diagnosed with bipolar mood disorder. The results suggest that both positive/manic symptoms and negative/depressive symp- toms are present in individuals diagnosed with schizo- phrenia and with bipolar mood disorder and, conse- quently, do not present a reliable means of differenti- ating between these two groups. These findings have many implications for the ways in which mental illness is conceptualized and classified. Treatment efforts and interventions may be enhanced if a more dimensional approach to diagnosing mental illness is utilized. Keywords: Classification; Depressive Symptoms; Mania; Diagnosis