Both migraine and Bipolar Disorder (BPAD) are complex phenotypes with significant genetic and non-genetic components. Epidemiological and clinical studies have demonstrated a high degree of co-morbidity between migraine and BPAD. Numerous genome- wide linkage studies in BPAD and migraine have shown overlapping regions of linkage on chromosomes, and two functionally similar voltage-dependent calcium channels, CACNA1A and CACNA1C, have been identified in familial hemiplegic migraine and recently in three BPAD genome-wide association studies (GWAS), respectively. We here present results from our ongoing study project. The reports include both a literature review, results from Genome-wide linkage and Genome-wide association studies. We hypothesised that the subgroup of patients presenting combined symptoms from two different brain disorders associated with disturbances in neuronal membrane passage (i.e migraine and BPAD) might reflect a complex neurodegenerative phenotype that could share an underlying genetic susceptibility. The findings of this study suggest that genetic variants in several genes essential for the formation and functioning of neuronal transmission, may predispose to migraine headaches in subgroups of patients with BPAD.