Understanding Anxiety Disorders, OCD, and PTSD
Anxiety is both a feeling and a cognition—a doubt-laden appraisal of one’s safety or social skill. How do these anxious feelings and cognitions arise? Sigmund Freud’s psychoanalytic theory proposed that, beginning in childhood, people repress intolerable impulses, ideas, and feelings. Freud believed that this submerged mental energy sometimes leaks out in odd symptoms, such as anxious handwashing. Few of today’s psychologists share Freud’s interpretation of anxiety. Most believe that three modern perspectives—conditioning, cognition, and biology—are more helpful.
Conditioning
Through classical conditioning, our fear responses can become linked with formerly neutral objects and events. In a classic experiment, an infant—“Little Albert”—learned to fear furry objects that researchers paired with loud noises (see Module 26). In other experiments, researchers have created anxious animals by giving rats unpredictable electric shocks (Schwartz, 1984). The rats, like assault victims who report feeling anxious when returning to the scene of the crime, had learned to become uneasy in their lab environment. The lab had become a cue for fear.
Such research helps explain why anxious or traumatized people learn to associate their anxiety with certain cues (Bar-Haim et al., 2007; Duits et al., 2015). In one survey, 58 percent of those with social anxiety disorder experienced their disorder after a traumatic event (Ost & Hugdahl, 1981). Anxiety or an anxiety-related disorder is more likely to develop when bad events happen unpredictably and uncontrollably (Field, 2006; Mineka & Oehlberg, 2008). Even a single painful and frightening event may trigger a full-blown phobia, thanks to two conditioning processes: classical conditioning’s stimulus generalization and operant conditioning’s reinforcement.
Stimulus generalization occurs when a person experiences a fearful event and later develops a fear of similar events. My [DM’s] car was once struck by a driver who missed a stop sign. For months afterward, I felt a twinge of unease when any car approached from a side street. Likewise, I [ND] was watching a terrifying movie about spiders, Arachnophobia, when a severe thunderstorm struck and the theater lost power. For months, I experienced anxiety at the sight of spiders or cobwebs. Those fears eventually disappeared, but sometimes fears linger and grow. Marilyn’s thunderstorm phobia may have similarly generalized after a terrifying or painful experience during a thunderstorm.
Reinforcement helps maintain learned fears and anxieties. Anything that enables us to avoid or escape a feared situation can reinforce maladaptive behaviors. Fearing a panic attack, we may decide not to leave the house. Reinforced by feeling calmer, we are likely to repeat that behavior in the future (Antony et al., 1992). So, too, with compulsive behaviors. If washing our hands relieves our feelings of anxiety, we may wash our hands again when those feelings return.
Cognition
Conditioning influences our feelings of anxiety, but so does cognition—our thoughts, memories, interpretations, and expectations. By observing others, we can learn to fear what they fear. Nearly all monkeys raised in the wild fear snakes, yet lab-raised monkeys do not. Surely, most wild monkeys do not actually suffer snake bites. Do they learn their fear through observation? To find out, Susan Mineka (1985, 2002) experimented with six monkeys raised in the wild (all strongly fearful of snakes) and their lab-raised offspring (virtually none of which feared snakes). After repeatedly observing their parents or peers refusing to reach for food in the presence of a snake, the younger monkeys developed a similar strong fear of snakes. When the monkeys were retested three months later, their learned fear persisted. We humans similarly learn many of our own fears by observing others (Helsen et al., 2011; Olsson et al., 2007).
Our past experiences shape our expectations and influence our interpretations and reactions. Whether we interpret the creaky sound simply as the wind or as a possible knife-wielding attacker determines whether we panic. People with anxiety disorders tend to be hypervigilant. They attend more to threatening stimuli. They more often interpret unclear stimuli as threatening: A pounding heart signals a heart attack; a lone spider near the bed indicates a likely infestation; an everyday disagreement with a friend or boss spells doom for the relationship. And they more often remember threatening events (Van Bockstaele et al., 2014). Anxiety is especially common when people cannot switch off such intrusive thoughts and perceive a loss of control and a sense of helplessness (Franklin & Foa, 2011).
Biology
There is, however, more to anxiety disorders, OCD, and PTSD than conditioning and cognitive processes alone. Why do some of us develop lasting phobias or PTSD after suffering traumas, but others do not? Why do we all learn some fears so readily than others? The answers lie in part in our biology.
Genes
Among monkeys, fearfulness runs in families. A monkey reacts more strongly to stress if its close biological relatives are anxiously reactive (Suomi, 1986). So, too, with people. If one identical twin has an anxiety disorder, the other is also at risk (Polderman et al., 2015). Even when raised separately, identical twins may develop similar phobias (Carey, 1990; Eckert et al., 1981). One pair of 35-year-old identical twins independently became so afraid of water that each would wade in the ocean backward and only up to her knees.
Given the genetic contribution to anxiety disorders, researchers are sleuthing the culprit genes. One research team identified 17 gene variations associated with typical anxiety disorder symptoms (Hovatta et al., 2005). Other teams have found genes associated specifically with OCD (Mattheisen et al., 2015; Taylor, 2013).
Some genes influence disorders by regulating brain levels of neurotransmitters. These include serotonin, which influences sleep, mood, and attending to threats (Canli, 2008; Pergamin-Hight et al., 2012), and glutamate, which heightens activity in the brain’s alarm centers (Lafleur et al., 2006; Welch et al., 2007).
So genes matter. Some of us have genes that make us like orchids—fragile, yet capable of beauty under favorable circumstances. Others of us are like dandelions—hardy, and able to thrive in varied circumstances (Ellis & Boyce, 2008; Pluess & Belsky, 2013).
But experience affects gene expression. Among those with PTSD, a history of child abuse leaves long-term epigenetic marks, which are often organic molecules. These molecular tags attach to our chromosomes and turn certain genes on or off. Thus, experiences such as abuse can increase the likelihood that a genetic vulnerability to a disorder will be expressed (Mehta et al., 2013; Zannas et al., 2015). People who commit suicide show a similar epigenetic effect (Lockwood et al., 2015; McGowan et al., 2009).
The Brain
Our experiences change our brain, paving new pathways. Traumatic fear-learning experiences can leave tracks in the brain, creating fear circuits within the amygdala (Etkin & Wager, 2007; Herringa et al., 2013; Kolassa & Elbert, 2007). These fear pathways create easy inroads for more fear experiences (Armony et al., 1998).
Generalized anxiety disorder, panic attacks, phobias, OCD, and PTSD express themselves biologically as overarousal of brain areas involved in impulse control and habitual behaviors. These disorders reflect a brain danger-detection system gone hyperactive—producing anxiety when no danger exists. In OCD, for example, when the brain detects that something is amiss, it seems to generate a mental hiccup of repeating thoughts (obsessions) or actions (compulsions) (Gehring et al., 2000). Brain scans of people with PTSD show higher-than-normal activity in the amygdala when they view traumatic images (Etkin & Wager, 2007). Brain scans of people with OCD reveal elevated activity in specific brain areas during behaviors such as compulsive hand washing, checking, ordering, or hoarding (Insel, 2010; Mataix-Cols et al., 2004, 2005). The anterior cingulate cortex, a brain region that monitors our actions and checks for errors, seems especially likely to be hyperactive (Maltby et al., 2005) (Figure 66.2).
Figure 66.2 An obsessive-compulsive brain
When people engaged in a challenging cognitive task, those with OCD showed the most activity in the anterior cingulate cortex in the brain’s frontal area (Maltby et al., 2005).
Some antidepressant drugs dampen this fear-circuit activity and its associated obsessive-compulsive behavior. Fears can also be blunted by giving people drugs as they recall and then rerecord (“reconsolidate”) a traumatic experience (Kindt et al., 2009; Norberg et al., 2008). Although they don’t forget the experience, the associated emotion is largely erased.
Natural Selection
We seem biologically prepared to fear threats faced by our ancestors. Our phobias focus on such specific fears: spiders, snakes, and other animals; enclosed spaces and heights; storms and darkness. Those fearless about these occasional threats were less likely to survive and leave descendants. Even in Britain, with only one poisonous snake species, people often fear snakes. Nine-month-old infants attend more to sounds signaling ancient threats (hisses, thunder) than they do to sounds representing modern dangers (a bomb exploding, breaking glass) (Erlich et al., 2013). It is easy to condition and hard to extinguish fears of such “evolutionarily relevant” stimuli (Coelho & Purkis, 2009; Davey, 1995; Öhman, 2009). Some of our modern fears can also have an evolutionary explanation. A fear of flying may be rooted in our biological predisposition to fear confinement and heights.
Fearless The biological perspective helps us understand why most people have more fear of heights than does Alex Honnold, shown here in 2017 becoming the first person to free solo climb (no safety ropes) Yosemite National Park’s El Capitan granite wall.
Compare our easy-to-learn fears with those we do not easily learn. World War II air raids, for example, produced remarkably few lasting phobias. As the air blitzes continued, the British, Japanese, and German populations did not become more and more panicked. Rather, they grew increasingly indifferent to planes outside their immediate neighborhoods (Mineka & Zinbarg, 1996). Evolution has not prepared us to fear bombs dropping from the sky.
Just as our phobias focus on dangers faced by our ancestors, our compulsive acts typically exaggerate behaviors that contributed to our species’ survival. Grooming had survival value. Gone wild, it becomes compulsive hair pulling. So too with washing up, which becomes ritual hand washing. And checking territorial boundaries becomes checking and rechecking already locked doors (Rapoport, 1989). Although natural selection shaped our behaviors, when taken to an extreme, these behaviors can interfere with daily life.