9% of migraineurs reported opioid use in the past 3 months for control. Of the opioid users, 16.6% met criteria for probable opioid dependence, representing 2.6% of the total sample of migraineurs. The prevalence of anxiety and depression was highest among current opioid users with probable dependence.[19] Recent studies in neuroimaging and pharmacogenetics suggest an overlap MAPK inhibitor between the pathophysiological mechanisms of MOH and substance-related disorders.[53] Functional magnetic resonance imaging data during the execution of a decision-making under risk paradigm found that MOH patients showed

dysfunction in the mesocorticolimbic dopamine circuit – particularly in the ventromedial prefrontal cortex and in the substantia nigra/ventral tegmental complex – when compared with several control groups. The ventromedial prefrontal cortex dysfunctions appear to be reversible based on comparison to a control group of MOH patients 6 months after drug withdrawal. In contrast, the substantia nigra/central tegmental area complete dysfunctions persist even 6 months after withdrawal, based on a comparison to CM and non-migraine controls.[54] Moreover, headache sufferers with personality disorders (PDs), in particular cluster B entities, may act out particular behaviors, such as defiance of limits regarding medication usage, battles of control over treatment, and attitudes of entitlement regarding

pain control, resulting in medication overuse.[55] DSM-5 defines a personality disorder as IWR-1 “an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual’s 上海皓元医药股份有限公司 culture, is pervasive and inflexible, has an onset in adolescence or early adulthood, is stable over time, and leads to distress or impairment.”[52] PDs continue to be grouped in 3 clusters: A (paranoid, schizoid, and schizotypal), B (antisocial, borderline, histrionic, and narcissistic), and C (avoidant, dependent, and obsessive–compulsive). The cluster B disorders are marked by self-serving traits that often

emerge in the doctor–patient relationship, such as deceit (antisocial), dramatic mood swings from idealizing to intense anger at the physician (borderline), seductiveness and drama (histrionic), and entitlement (narcissistic). Of potential interest is a new PD diagnosis in DSM-5: “personality change due to another medical condition,” which refers to medically related persistent personality changes that deviate significantly from the individual’s previous characteristic personality pattern. In a sample of 267 patients who completed a multidisciplinary inpatient treatment program, MOH was more common in those with a PD diagnosis (62%) than those with no PD (38%).[55] The presence of borderline PD, moderate-severe depression, and MOH may be an unfortunate trifecta associated with poor outcomes from outpatient treatment programs.