amygdala – Hibernator's Library

Most people are familiar with obsessive compulsive disorder as is popularized in many TV shows and movies. My favorite is Monk, a TV show about Adrian Monk, an investigator who works with the San Francisco police department. Due to Monk’s severe OCD (along with other disorders), he was forced into retirement as a detective with the San Francisco PD. The show is unflinching about the negative effects of Monk’s disorder, but of course it introduces humor into his predicament.

According to the DSM-5, obsessions are “recurrent and persistent thoughts, urges, or images” that are intrusive and cause distress. The individual attempts to ignore the obsessions, but is generally unable to. Compulsions are repetitive behaviors – such as hand washing, checking, praying, counting, or word repetition – that the individual feels compelled to perform in order to reduce anxiety and distress.

Often, the compulsion is meant to prevent a terrible event. That event is often excessive or unrealistic. To give a rather trite but recognizable example, someone might try not to step on cracks because they’d “break their mother’s back,” so they must go back to the beginning again and again just to make sure they didn’t step on any of the cracks. Ritualistic hand washing is generally meant to protect the individual from contamination of germs. Adrian Monk, from my example above, had his assistant carry around hand-wipes so that Monk could clean up after he’d shaken hands with anyone.

OCD can be one of the most debilitating mental disorders because it can take up hours of a person’s day. In order to get a diagnosis, the obsessions or compulsions must take up at least 1 hour each day.

Generally the individual is quite aware that his compulsion is excessive and unnecessary. Monk was an intelligent guy – he knew that if he didn’t touch-and-count every car antenna in that traffic jam that nothing bad would happen. But he couldn’t stop himself, even though it slowed down his progress as he walked up to the “crime scene.”

Common obsessive thoughts include contamination fears, fears of harming oneself or others, and pathological doubt. Another common obsession is the need for symmetry. Mr. Monk had all of these obsessions. Obsessions about sex and aggression are also common. (Well, Monk wouldn’t be as likable if he had those, though he did have a phobia of sex and nudity). OCD is often accompanied by social phobia, panic disorder, generalized anxiety disorder, and PTSD. (Yup. Monk had all of those.)

OCD is thought to be a learned behavior. First, the individual begins to obsess that touching a doorknob will contaminate his hands. As his anxiety increases, he finally breaks down and washes his hands. Washing his hands decreases his anxiety tremendously – he has now learned how to alleviate his distress. So the next time the obsessive thought intrudes, he will wash his hands again. Perhaps this time, he’ll just keep on washing his hands, because that might decrease the anxiety more. Of course, this theory doesn’t explain where the obsessive thoughts come from in the first place.

Top left: basal ganglia; Top right: amygdala;
Bottom: thalamus

In patients with OCD, abnormalities occur primarily in the basal ganglia. The basal ganglia are involved in primitive behaviors such as sex, aggression, and hygiene concerns. In a system known as the cortico-basal-ganglionic-thalamic circuit, urges are passed from the basal ganglia through the caudate nucleus, which filters the urges before sending them to the thalamus, which, in turn, sends the signal to the frontal cortex to create an action-urge. Theories suggest that in OCD, there is something wrong with the filtering aspect of this system, and many inappropriate urges are sent on to the cortex. In addition to connecting to the cortico-basal-ganglionic-thalamic circuit, the basal ganglia is also linked to the limbic system through the amygdala, which is thought to be the source of the “fear network,” as described in my post about panic disorder. This connection explains the panic that the individual feels when the obsessive urges aren’t acted upon.

The most successful treatment for OCD is exposure and response prevention. The individual is asked to rate his disturbing stimuli on a scale of 1 to 100. The individual then exposes himself repeatedly to a stimulus (either by imagination or directly) and is asked not to perform the compulsion. Eventually, the anxiety subsides on its own. Theoretically, each time the individual avoids the compulsion, he becomes a little more sure that the compulsion is not necessary to decrease the anxiety.

For those of you who are interested, Mr. Monk’s greatest fears, in order, are: germs, dentists, sharp or pointed objects, milk, vomiting, death and dead things, snakes, crowds, heights, fear, mushrooms, and small spaces (as listed in the episode “Monk and the Very, Very Old Man). Fortunately for him, his work frequently throws him into situations in which he encounters these things and is unable to fulfill his compulsions. I guess working his its own therapy. 🙂

This is a series of posts summarizing what I’m learning in my Abnormal Psychology course. Much of the information provided comes from reading my James N. Butcher’s textbook Abnormal Psychology. To read the other posts, follow these links:

The Definition of Abnormal
A History of Abnormal Psychology
Abnormal Psychology in Contemporary Society
Contemporary Viewpoints on Treating Mental Illness – Biology
Contemporary Viewpoints on Treating Mental Illness – Psychology
Frontline: New Asylums
Brave New Films: This is Crazy
Clinical Mental Health Diagnosis: Biological Assessment
Clinical Mental Health Diagnosis: Psychological Assessment
Does the DSM Encourage Overmedication?
Post Traumatic Stress Syndrome – The Basics
Panic Disorder
Obsessive Compulsive Disorder
Hoarding and Body Dysmorphic Disorders
Depression – an Overview
Personality Disorders – Clusters and Dimensions
Personality Disorders – Cluster A
Personality Disorders – Cluster B
Personality Disorders – Cluster C
Biological Effects of Stress on Your Body
Somatic Symptom and Related Disorders
Dissociative Disorders
Borderline Personality Disorder
Dialectical Behavioral Therapy
Paraphilic Disorders
Gender Dysphoria – Homosexuality and Transgender
Anxiety Disorders
Bipolar Disorder – The Basics
Suicide – An Overview

References:

Butcher, James N. Hooley, Jill M. Mineka, Susan. (2014) Chapter 6: Panic, Anxiety, Obsessions, and their Disorders. Abnormal Psychology, sixteenth edition (pp. 163-210). Pearson Education Inc.

Fear is an emotion that elicits the “fight-or-flight” response of the autonomic nervous system. It is an immediate (uncontrollable) response to a direct danger – such as a rattlesnake, a gun pointed at your head, or a fast car driving right at you. Fear is generally a helpful response that allows you to protect or remove yourself from the imminent peril.

Sometimes the fear response can occur in the absence of any obvious stimulus – this can lead to a panic attack. Panic attacks are terrifying physiological and psychological events in which your autonomic nervous system ramps you up for fight-or-flight. Often, the person becomes terrified that they are dying – usually of a heart attack. Like intense fear, the heart starts pounding, adrenaline flows, breathing races. Sometimes the victim will run from the room – perhaps to a hospital or perhaps with no direction at all – to escape the unseen threat.

A person who experiences frequent panic attacks can be diagnosed with panic disorder. A person with panic disorder is terrified of having another panic attack – and even that fear can elicit another attack. Such a disorder can be crippling. I have a friend with panic disorder that struggled in college because she’d had a panic attack during a particular class, and she was intensely afraid to go back to that class, fearing that she might have another attack. According to the DSM-5, in order to have panic disorder, a person must have 4 of 13 symptoms including: pounding heart, sweating, trembling, shortness of breath, choking, chest pain, nausea, dizziness, chills or heat, numbness or tingling, feelings of unreality, fear of “going crazy,” or fear of dying.

Panic attacks usually last 20-30 minutes with a peak for about 10 minutes, which is good because any longer than that could pose an immediate danger to the person’s metabolism (in case of diabetes) or cardiovascular system (heart attack).

The fear response in a panic attack originates in the amygdala, which is thought to be the central component of the “fear network.” According to the prevailing theory, panic attacks occur when the fear network is activated. Panic disorder develops in people who have a non-adaptive fear network which is overly-sensitive. Although the physiological response to a panic attack originates in the amygdala, there are also cognitive components to panic disorder (e.g. fear of another panic attack in particular situations). The hippocampus, which is involved in learning and emotional responses, is likely involved in this aspect of panic disorder. The cognitive factors in panic disorder (e.g. fears of dying or going insane) are likely controlled by higher cortical centers of the brain.

There are a couple of theories about the development of panic disorder. In the comprehensive learning theory of panic disorder, a person undergoes classical conditioning – such as Ivan Pavlov discovered when his dogs began to salivate reflexively to the sound of a metronome that was always ticking when the dogs ate. In a process called interoceptive conditioning, the person begins to unconsciously associate physiological arousal (e.g. pounding heart, head rush, increased breathing rate) with panic. Thus, when a person is physiologically aroused, such as while running, she will suddenly experience a panic attack. Panic attacks can also be induced by happy events. For instance, when something exciting happens, such as a marriage proposal, the happy person can suddenly rush into panic.

Another theory of panic disorder is the cognitive theory. In this case, the person consciously associates physiological arousal with impending doom. When his heart is pounding, he thinks he could be having a heart attack. When his breathing becomes labored, this could be lung cancer. Such thinking is called “catastrophizing.”

Panic provocation studies support the cognitive theory of panic disorder. In such a study, a subject is given a stimulant that increases heart rate or other physiological symptoms of arousal. One test group is told in advance that the stimulus will increase heart rate, and that it is completely harmless. The other test group will not receive any explanation. It turns out that people who are forewarned of the physiological arousal are less likely to experience a panic attack. This is not in line with the comprehensive learning theory, in which the panic is induced reflexively, and cognition has nothing to do with the attack.

In all likelihood, both theories play some part in the origin of panic attacks.

Many people with panic disorder are prescribed benzodiazapines such as Xanax or Klonopin. These medications are very useful for anxiety relief, but they can be addictive. Upon cessation of the medication, a patient can undergo uncomfortable side effects such as nervousness, sleep disturbance, dizziness, and panic attacks. For those of you who wonder why we are so dependent upon medications for treatment of anxiety, try undergoing a three hour anxiety attack like the one described in My Bipolar Mixed State. You will soon understand that immediate relief is necessary.

Because of the negative side effects of medication, it is good to treat panic disorder with psychological therapy, such as cognitive-behavioral therapy, as described in Contemporary viewpoints on treating mental illness – psychology. In such treatment, a patient can be exposed to internal stimuli of physiological arousal; for instance, running in place, spinning in a chair, or hyperventilating. The patient must continue this activity until he dissociates the physiological symptoms with panic. Such deconditioning therapy can be combined with education about the nature and causes of panic disorder. The patient can be taught to meditate or control their breathing. Patients are also taught about the cognitive errors that they might be making (i.e. my heart is pounding, I must be having a heart attack).

References:

Butcher, James N. Hooley, Jill M. Mineka, Susan. (2014) Chapter 6: Panic, Anxiety, Obsessions, and their Disorders. Abnormal Psychology, sixteenth edition (pp. 163-210). Pearson Education Inc.