Abstract
The exact cause, or rather the causes, of bipolar disorder are not known and most researchers now agree that there is no single etiological factor that accounts for all instances of the disorder. Rather it would appear that several factors combined lead to the behavioral manifestations, or symptoms, collectively referred to as bipolar disorder (National Institute of Mental Health [NIMH], 2008). As illustrated in Fig. 2.1, this disorder is thought to be a neurobiological disorder (associated with certain brain regions and the dysfunction of certain neurotransmitters). In turn, these brain differences are thought to be associated with genetic factors, external environmental stressors, and/or the interactions among these variables (Bressert, 2007).