It seemed like a textbook case of depression. The patient, a male in his late 30s, was in counseling for marital difficulties. He was socially withdrawn and had started drinking heavily. His speech and movements were slow. Yet even as he fought back tears in a session with his psychiatrist, Natasha Thomas, he could not describe how he felt. “When he would cry, I'd ask, ‘How are you feeling?' and he would shrug,” Thomas says. “I would give him words like, ‘sad, hopeless, frustrated.’” Her patient would reply, “What do those things feel like?”

Thomas's patient suffered from more than just depression—he also has alexithymia, a personality trait characterized by deficits in the ability to identify and describe one's emotions. People high in this trait also tend to think in concrete, utilitarian terms rather than in a way that emphasizes insight and internal experience, and they have a limited capacity for imagination, fantasies and dreams.

Although it may sound like a condition or disorder, alexithymia is actually a dimension of personality, akin to conscientiousness or neuroticism, and it tends to remain stable over time. About 10 percent of the population possesses the extreme characteristics of alexithymia, with the rest of us falling somewhere along a continuum. The trait's occurrence is influenced by developmental and cultural factors [see box on opposite page], but there is also a strong genetic component associated with alexithymia. Researchers at the Italian National Institute of Health have found that 42 percent of individual differences in alexithymia are ascribed to genetics.

Chances are we all know someone who meets the description of alexithymia, yet few people are familiar with the term. In part this is because the overlapping concept of emotional intelligence, or the capacity to understand, recognize and respond to emotions in others and oneself, has eclipsed alexithymia in the public awareness. Emotional intelligence, however, does not encompass the deficits in imagination and dreaming typical of alexithymia, suggesting the trait relates to a broader struggle with internally focused thinking. Communication scientist Colin Hesse of the University of Missouri believes many people fail to recognize the seriousness of this trait: “[They] don't really believe that some people honestly might be disadvantaged, on a neurological level, in understanding and communicating emotions.”

As recent research is now revealing, alexithymia has deep implications for numerous aspects of life. Beyond its association with several mental disorders, including anxiety and depression, alexithymia also can affect the quality of relationships and many facets of physical health. The good news is that emerging therapies show promise for helping people with alexithymia to develop an awareness of their emotions, enrich their inner lives and improve their overall well-being. Ultimately insights into this long-overlooked trait lay bare the intimate connection between mind and body. To ace life, you have to understand your emotions.

Soul without Words

Psychiatrists have long recognized that failing to get in touch with one's feelings extracts a physical toll. In the early 1970s the late psychiatrist Peter E. Sifneos of Beth Israel Hospital (now Beth Israel Deaconess Medical Center) in Boston noticed that many of his patients with psychosomatic illnesses, in which a mental disorder manifests as physical illness or injury, were unable to understand or express their emotional experiences. Sifneos coined the term “alexithymia,” from the Greek for “soul without words,” to describe the phenomenon.

Researchers have since discovered that alexithymia is comorbid with multiple mental disorders, including obsessive-compulsive disorder and addiction. Rates of alexithymia are especially high among the chronically depressed. But as Sifneos suspected, alexithymia's damage goes beyond mental health. Diabetes, heart disease, hypertension and certain gastrointestinal disorders are all linked with the trait. A study of 101 patients with type 2 diabetes published in February in Psychiatry Research found that having the trait nearly doubles the risk of developing diabetes.

Another equally powerful factor is alexithymia's effect on interpersonal ties. A wealth of data backs the notion that strong social connections are vital to a healthy way of life. But alexithymia makes it harder to create and expand a supportive social network. Hesse has observed that alexithymia can hinder an individual's ability to begin, grow and maintain all kinds of close relationships. In 2010 Hesse found that after a 10-minute initial interaction, people were much less socially attracted to alexithymic individuals than nonalexithymic individuals. He has also shown that people with alexithymia are more likely to avoid and distrust others. When in relationships, people with this trait self-disclose less, give and receive less affection, and derive less joy from intimate interactions.

Heather Foran, a research psychologist at the Technical University of Braunschweig in Germany, believes that these relationship challenges cause negative emotions to persist longer than they otherwise might. In a study published in 2012 she and her colleagues discovered that measures of emotional intelligence and alexithymia could predict mood and relationship quality among 104 American couples. Foran found that without emotional disclosure, partners struggled to support each other, thereby increasing their risk of depression and dissatisfaction.

When Feelings Are Foreign

To understand how an emotional disconnect can create devastating physiological and interpersonal effects, scientists are looking to the brain. By stimulating the brain with magnetic pulses and observing how electric current then travels through neural tissue, researchers have found that people who are high versus low in alexithymia differ in the way their brain's two hemispheres communicate. Highly alexithymic individuals do not appear to transfer information between the two sides of the brain as well as people who rate lower in this trait. These individuals, therefore, may struggle to integrate various types of information, such as emotional cues.

Other brain-imaging studies indicate that people scoring high in alexithymia show reduced activity in brain areas associated with emotion regulation and self-related thoughts. For example, a 2013 study by researchers at three universities in Germany found that individuals with alexithymia have less gray matter in the anterior insula, which helps to govern emotions as well as interoception. This lesser-known sense encompasses the perception of one's internal bodily states, such as hunger pangs or an accelerating heartbeat. The same neural processes that underlie interoception, it seems, can also explain the ability to detect and decipher emotions.

Other work bolsters the connection. In a study from 2011 Beate M. Herbert, a research scientist now at the University of Ulm in Germany, and her colleagues tested 88 women and 67 men for alexithymia and measured their interoception by asking them to count how many times their heart beat in a minute (people with poor interoception tend to fare worse on this task). The team confirmed that interoceptive sensitivity was inversely associated with all facets of alexithymia. Moreover, in March 2013 a Japanese research group found that neural pathways relating to awareness of both bodily and emotional states overlap, leading the authors to conclude that awareness of emotions requires interoception.

Yet a failure of interoception does not mean that emotions do not exist. Psychologist Tom Hollenstein of Queen's University in Ontario believes that in alexithymia, the typical mental and physical responses to an emotional event have decoupled. In 2013 Hollenstein and his colleagues measured the heart rate and electrical conductance of skin—which varies as a person sweats—of participants giving an impromptu speech. They then compared these physiological measures with participants' self-reported feelings of self-consciousness, along with other observers' assessments of each speaker's mental state. The researchers found that people high in the trait failed to integrate their physical and mental reactions. “Alexithymics have emotions like everyone else, but they appraise them differently,” Hollenstein says.

A failure to integrate bodily responses and emotional cues might explain why people with alexithymia are more prone to disease. If you cannot recognize your body's needs, maintaining a healthy lifestyle becomes difficult. Hans Thulesius, a physician at Lund University in Sweden, has proposed that individuals who struggle to discern their feelings may also be unable to assess symptoms such as fatigue, which can indicate changing blood glucose levels. And they may fail to regulate stress effectively by being slow to act when the body's fight-or-flight response kicks in. Maintaining an elevated stress response could exhaust the body and leave it vulnerable to sickness. Indeed, several studies have found that the diseases most closely associated with alexithymia—coronary heart disease, diabetes, hypertension and certain gastrointestinal disorders—also involve lower heart rate variability. This symptom is a marker of an unchecked stress response, which is exactly what researchers would expect to see if alexithymia and reduced interoception interfered with a person's ability to manage the body's needs.

Emotional Education

With mounting evidence that emotional awareness promotes healthier minds, bodies and relationships, finding ways to get in touch with one's feelings has become more important than ever. Given the limited malleability of personality traits, some experts have taken a pessimistic view of therapies. Fortunately, certain treatments have recently shown promise in not only reducing alexithymia but also improving related health and relationship outcomes. Social skills and emotional intelligence, for example, can be targeted through therapy. In a 2013 study in the Asian Journal of Psychiatry, alexithymic participants with dyspepsia, a form of chronic indigestion, received medication and underwent 16 weeks of group therapy focused on understanding and resolving interpersonal problems. Afterward, they had better health and lower alexithymia scores than patients who received only medical treatment for their dyspepsia.

Yet it remains an open question which of the many available psychotherapies work best. A randomized trial published in 2013 was the first to compare methods; its results indicated that a supportive approach, emphasizing an individual's strengths and teaching him or her social skills, was nearly twice as effective as a common interpretive treatment focused on identifying unconscious conflicts. The reason may be because the latter approach requires inward-thinking skills typically deficient in those with alexithymia.

Certain basic interventions can help people across the alexithymia scale. Therapies incorporating body-based techniques, for instance, can enhance a patient's awareness of and response to physical sensations and emotions. An example is progressive muscle relaxation, which entails paying close attention to the body while tensing and relaxing every muscle from head to toe.

For patients who struggle with mood and eating disorders, addiction and sexual trauma, among whom alexithymia is common, basic emotion education is often helpful. Typically the first step is to recognize the difference between thoughts and feelings. This can involve reviewing a “feelings list,” which breaks down the nuanced variations of universal emotions. Using the list, patients pick out a feeling that seems like it might match a particular situation they have experienced and then “try it on” to decide whether it feels accurate. The therapist and client discuss how other people tend to feel in these situations and what physiological sensations accompany an emotion. It can be useful to refer to expressions such as “I had a lump in my throat,” “butterflies in my stomach,” “my heart dropped” or “I was steaming.”

Some patients also benefit from having a therapist point their attention to bodily cues, such as the tense shoulders and constricted breathing typical of anxiety. As patients begin piecing together their emotional puzzle, they become more inclined to observe their internal experience. Mindfulness techniques, which emphasize nonjudgmental observation rather than pressuring patients to figure out or fix emotional states, can be invaluable at this stage. The success of these types of interventions may derive in part from the way they approach emotional awareness from the outside in.

Further gains may come from new efforts to create a “bodily map of emotions.” In a study in 2013 in the Proceedings of the National Academy of Sciences USA, a group of researchers led by psychologist Lauri Nummenmaa of Aalto University in Finland asked 701 participants from Finland, Sweden and Taiwan to color the parts of the body that experienced a change in sensation in response to events such as watching a touching movie or observing certain facial expressions. The researchers discovered that across cultures, respondents consistently associated specific regions of the body with particular emotions. For example, people felt a sense of increased activation in the arms and upper body when angry, whereas happiness led to a flood of stimulation from head to toe. Teaching people to associate sensation in various regions of the body with a corresponding emotion could help them learn how to reconnect bodily responses with emotional reactions.

For those of us who do not struggle with recognizing emotion, research on alexithymia may be a reminder that this recognition is a gift. The same mechanisms that help us understand why we laugh, cry, reach for a snack or sit down for a rest also equip us to build relationships and keep tabs on our physical health. So listen to your inner chorus—what you hear might matter a great deal.

Origins of Alexithymia

Most people learn to differentiate between feelings in childhood, when caretakers teach children the words to name feelings. It is no surprise then that many researchers suspect developmental factors play an important role in alexithymia. In 2012, for example, physicians at the Erenky Mental Research and Training Hospital in Istanbul found that emotional abuse and neglect could predict the emergence of alexithymia.

Culture, too, could play a part in the occurrence of alexithymia by de-emphasizing emotional experience. A 2013 study compared 388 Spaniards, who have a culture that is generally liberal and individualistic, with 537 Uruguayans, who hail from a more traditional and collectivist society. The Uruguayans reported placing less value on sharing personal emotions than the Spaniards. Similarly, multiple studies conducted by psychologist Andrew Ryder of Concordia University in Montreal have revealed that traditional Chinese culture de-emphasizes self-focused thinking, encouraging people to think more externally—that is, about others, objects and forces outside the self. Yet a collectivist culture need not breed alexithymia. Ryder found that despite an outward focus, emotional awareness remained intact in these societies.

Gender norms can add another layer of environmental influence. Traditional gender roles generally discourage men from paying attention or assigning importance to their emotions. This tendency has led researchers such as Ronald F. Levant of the University of Akron to coin the concept of “normative male alexithymia,” in which society socializes young men to become emotionally stunted. He observes that men may develop a nonpathological variant of the alexithymia trait. Some data support this position: in 2008, for instance, Arizona State University psychologists found that Mexican-American men who exhibited more machismo—an outlook that endorses aggressive hypermasculinity—also had higher alexithymia scores.

Difficult circumstances can also produce temporary bouts of “state alexithymia.” In such cases, trauma or a depressive incident triggers a sharp disconnect from emotional awareness. Compared with the stable and enduring “trait alexithymia” discussed in the main article, this state is even less researched and poorly understood. Fortunately, state alexithymia wanes with time. —T.R.