Sulfur Amino Acid Metabolic Process Pathway may Modulate Bipolar Disorder with Alcohol Dependence Comorbidity

Alcohol comorbidity in Bipolar Disorder (BD) attracted much attention during the last years [1] because of its relevant impact on prognosis. Co-occurrence of alcohol misuse during BD is common [2,3] and patients with both types of disorder are typically more difficult to treat than patients who have either problem alone [4]. BD shows a 1% prevalence worldwide, which rises up to 6.4% when subthreshold cases are, included [5]. Its costs were estimated to be $45.2 billion in 1991 (in the U.S.) [6]. Alcohol use disorders concern 25% of adults in the U.S. [7] overall economic cost was estimated to be $148 billion for 1992, $166.6 billion in 1995 and $184.6 billion in 1998 [8]. Moreover, alcohol use is the third leading preventable cause of death [9]. Thus, the costs of the combination of BD and alcohol use disorders are extremely high [10] and projected to increase. In this prospective alcohol dependence is one of the biggest problems related to alcohol [11] and its impact is particularly high in BD patients. Studies showed that 27.6% of any BD and especially 31.5% of BD type I patients suffered of alcohol dependence [12]. This comorbidity resulted in an increased risk for suicide attempt, greater severity of symptoms and impaired functioning. Compared with the lower rate of patients that suffer comorbidity of alcohol dependence with unipolar depression (11.6%) or with any mood disorder (4.9%), BD and alcohol dependence reveals a even stronger relationship [12]. As a consequence, the proper treatment of BD patients and the identification of subjects at risk is a priority. Consistently, a brain degeneration during BD is reported to be a late-phase characteristic that depends on the number of episodes of illness [13] and alcohol dependence could play a role in worsening this relapses number. Moreover, a proper treatment following the identification of BD patients at risk for alcohol dependence could Abstract