Research regarding the relationship between family communication and comorbid diagnoses in youths diagnosed with Bipolar Disorders is scarce. Existing research supports the importance of family communication with psychological development of children and adolescents affected by mental illness. The disruptive nature and increased dangers associated with Bipolar Disorders justifies further research. This dissertation study used archival data to answer research hypotheses to gain understanding the relationship between family communication and a diagnosis of a Bipolar Disorder. General Linear Model analysis and Analysis of Variance were used to test for significant differences in family functioning between families where a youth member had a diagnosis of a Bipolar Disorder versus varied comorbid diagnoses. Comorbid diagnoses configurations were the independent variables. The diagnoses configurations compared were a Bipolar Disorder only, compared to a Bipolar Disorder and any other diagnosis on Axis I A Bipolar Disorder only, compared to a Bipolar Disorder and ADHD A Bipolar Disorder only, compared to a Bipolar Disorder and Substance Disorder and a Bipolar Disorder only, compared to a Bipolar Disorder, ADHD and Substance Disorder. Family functioning was assessed by three dependent variables which were the General Functioning, Problem Solving and Family Communication subscales of the Family Assessment Device (Epstein, Baldwin, & Bishop, 1983). Family communication was not found to be statistically significant for any comorbid combination tested. General functioning and problem solving were statistically significant but small sample sizes prohibit generalizations. Limitations included small sample sizes, individual rather than multiple family member assessment and the omission of nonverbal behaviors as a form of communication. Discussion explores possible factors accounting for insignificance and low sample size