BA could be particularly suitable for treating depression among patients with chronic pain, as some of its main purposes are fighting inactivity, increasing environmental reinforces, and decreasing aversive experiences. Indeed, inactivity, loss of reinforces, and excessive unpleasant experiences seem to play a key role in the etiology of both depressive disorders and chronic pain (Dimidjian et al., 2011, Leeuw et al. 2007). According to Lewinsohn's integrative model of depression (Lewinsohn, Hoberman, Teri, & Hautzinger, 1985), when a person with certain vulnerabilities faces a stressful event, that event and the emotions associated with it interrupt their normal behavior patterns, reduce the availability of the reinforcers in the environment, and increase the rate of aversive experiences. All this finally leads to depression. Depressive symptoms have a series of behavioral, cognitive, and emotional correlates that make the subject more vulnerable to new stressful events, thus creating a pathological cycle that is self-perpetuating in time. Something similar occurs when a person suffers a painful injury. According to Vlayen and Linton's Fear and Avoidance Model (FAM, 2000), in the face of a painful injury, vulnerable individuals (with increased pain catastrophizing or increased pain-related fear) develop strategies aimed at avoiding pain and the activities that cause it. This leads to inactivity, loss of reinforcers, disability, and depression, and consequently, to the exacerbation of the pain intensity and pain-related anxiety and catastrophizing. The patient is trapped in a vicious circle of symptoms that feed-back each other and perpetuate over time. Taking into account the FAM assumptions, as well as the purpose of the BA, this treatment may likely not only be useful for reducing depression in patients suffering from pain, but also for reducing the intensity of their pain and the anxiety and catastrophism associated with it. BA could break the chain of perpetuation in both disorders. In fact, there are preliminary data that support this premise. In a case study, in which BA was used with a woman who had been suffering from chronic pain associated with a diagnosis of fibromyalgia for 11 years, a clinically significant decrease in depressive symptoms was observed after treatment. In addition, the degree in which the pain interfered with the patient's daily activities was reduced (in a 100%), as well as pain-related anxiety and the use of pain medication use. These results (with the exception of reduction in medication use) were maintained within three months of the intervention (Lundervold, Talley, & Buermann, 2006). These same authors replicated these findings in another study, in which they applied the same treatment to another woman who had been suffering from fibromyalgia for 22 years. In this case, the decreases of pain intensity, pain-related anxiety, depression, and medication use were maintained three and six months after the intervention (Lundervold, Talley, & Buermann, 2008).