There are a variety of ways in which our emotions can cause us difficulties. For some of us, affective lability - rapidly shifting emotional states - is the problem, leaving us in an unpredictable, frequently aversive state that feels difficult to control. Others of us experience more frequent or more severe negative moods, so we encounter more powerful emotions more often than others. For some of us, the problem is alexithymia - an inability to effectively identify our emotions, which leads to a broad sense of feeling "bad" that is difficult to regulate. For others of us, the problem is anhedonia, an inability to feel positive emotions in response to things that previously felt pleasurable, which leaves us feeling numb, disconnected, and unmotivated. There are several other ways in which our emotions can cause us problems and an entirely comprehensive list would be almost impossible. Today, I will focus on one particular emotional variable, distress tolerance, which is defined as the degree to which an individual experiences emotions as overwhelming (Simons & Gaher, 2005).
When I explain distress tolerance to a client or student, I tend to start with a bit of an odd metaphor. I tell the person to imagine each person is a glass of water. Each glass is uniform, holding the exact same amount of liquid, and each glass is sitting under a faucet that pours water out at the same rate. Next, I tell the person to imagine that my glass of water starts with more water in it than any other glass. Given this situation, even though my glass is being filled at the same rate with the same amount of water, mine will overflow more quickly than other glasses. In this metaphor, my glass has low distress tolerance. When an individual has low distress tolerance, it's not that he experiences more powerful emotions, more frequent negative emotions, or more confusing emotions. The issue is simply that, what does not feel overwhelming to others feels overwhelming to him. His glass already has more water in it, so it takes less to overflow.
Fortunately, there is a lot of empirical research on distress tolerance that does not rely on my glass metaphor. In this research, scientists have found that low levels of distress tolerance predict a host of problematic behavioral outcomes. Women tend to have lower levels of distress tolerance than men, but low distress tolerance is equally destructive regardless of sex (Simons & Gaher, 2005), much like rumination. Brandon and colleagues (2003) found that smokers with low distress tolerance were less able to sustain quit attempts than were smokers with moderate or high levels of distress tolerance. Similarly, Daughters, Lejuez, Kahler, Strong, and Brown (2005) found that individuals with low distress tolerance receiving treatment at a substance abuse treatment facility were less able to sustain quit attempts than were individuals at that same facility with higher levels of distress tolerance. Additionally, in a separate study, Daughters and colleagues (2005) found that individuals with low distress tolerance were more likely to drop out of a substance abuse treatment facility. These findings make a lot of sense and go a long way towards explaining why overcoming addiction is more difficult for some individuals than others (although by no means explains it all). Withdrawal is an extremely uncomfortable, distressing experience. If an individual is already inherently less able to tolerate even moderate levels of distress, this experience becomes that much more difficult.
Distress tolerance has been shown to be important in several other behavioral outcomes as well. Daughers and colleagues (2005) found that pathological gamblers with low distress tolerance were less able to sustain quit attempts. In a paper I co-wrote with Eddie Selby, Erin Fink, and Thomas Joiner (2007), we found that individuals with low distress tolerance were more likely to binge eat and purge than are individuals with higher levels of distress tolerance. Nock and Mendes (2008) found that individuals with who frequently engage in non-suicidal self-injury (NSSI) also have low levels of distress tolerance, which is particularly problematic given the relationship between NSSI and the acquired capability for suicide. Given all of these findings, it becomes readily apparent that not being able to tolerate negative emotions results in significant impairment.
So why would low distress tolerance motivate somebody to engage in such harmful behaviors? The answer is similar to the information we discussed in a prior article on the functional model of NSSI. When we hit a particular threshold of feeling upset, our priorities become almost entirely focused on immediately reducing our distress. For most of us, this threshold is quite high - it takes a lot for us to act in a way that completely disregards potential long-term consequences. When an individual has low distress tolerance, however, it takes less stress for them to reach their threshold - there is already more water in their glass. There is compelling evidence that, if we believe a behavior has the ability to reduce our feelings of negative affect, we are more likely to engage in that behavior, even if it is unhealthy, (e.g., binge eating; Fischer & Smith, 2008). There is also compelling evidence that some unhealthy behaviors have the ability to quickly reduce negative emotions (Smyth et al., 2008). This is unfortunate because, as an individual learns that a behavior can quickly reduce feelings of negative affect, they become more likely to do it again the next time they reach that threshold. If the threshold is low, they can quickly get stuck in a viscious cycle.
Fortunately, researchers have developed empirically supported treatments that directly address distress tolerance. Dialectical behavior therapy (DBT; Linehan, 1993a; Linehan, 1993b) is a form of cognitive behavioral therapy (CBT) that was originally designed to treat borderline personality disorder (BPD), which is characterized by highly labile emotions, difficulties regulating behavior when upset, stormy interpersonal relationships, and self-injury. Several studies have indicated that DBT is an effective treatment for BPD (e.g., Linehan, 1998), which is an important and often misunderstood fact due to some particularly harmful and prevalent misinformation about that disorder. DBT, which we will describe in more detail in future articles, includes a module that focuses entirely on teaching clients distress tolerance skills, ways to weather the storm when no healthy behavior is capable of changing the way they feel in that moment. Such skills include radical acceptance - a skill that teaches individuals to shift their focus from the way they wish things were to the way they actually are, accepting reality and devising plans to attain the best possible outcome given their circumstances. Recently, several researchers have demonstrated that DBT has empirical support as a treatment for both bulimia nervosa and binge eating disorder (Safer, Lock, & Coutourier, 2007; Safer, Telch, & Agras, 2001; Telch, Agras, & Linehan, 2001). More work needs to be done to demonstrate that DBT is an effective treatment for individuals whose distress tolerance has resulted in substace abuse or other problems; however, an important consideration to keep in mind is that such individuals may also meet criteria for BPD, bulimia, or binge eating disorder and thus benefit from DBT.
Ultimately, it appears that low levels of distress tolerance can be highly dangerous, in that they are correlated with an increased use of harmful behaviors, but that distress tolerance is a good target for therapeutic interventions. By understanding the mechanisms behind behaviors, whether this means distress tolerance, affective lability, or some other variable, researchers can be better equipped to design and test treatment protocols that have a greater likelihood of reducing rates of harmful behaviors. Additionally, by understanding such mechanisms, it becomes clear how behaviors that might seem unrelated, such as binge eating, NSSI, and substance abuse, actually share important risk factors and, as such might respond to similar treatments.