Lecture psychiatric disorders 11: neurobiology of Anti-Social Personality Disorder (ASPD) Flashcards
What is antisocial behavior?
Behavior that lacks consideration for others and that may cause damage to society
When is a patient diagnosed with Antisocial Personality Disorder (ASPD)?
A patient is diagnosed with ASPD when their antisocial behavior becomes pathological, where they consistently show no regard for right and wrong and ignore the rights and feelings of others.
Is psychopathy the same as Antisocial Personality Disorder?
No, psychopathy is a subset of ASPD. Characteristics of a psychopath differ from the characteristics of other types of ASPD.
What is Conduct Disorder (CD)?
Childhood antisocial disorder
What are characteristics of someone with Antisocial Personality Disorder (ASPD)?
- Apparant lack of remorse
- Persistent lying or stealing
- Cruelty to animals
- Recurring difficulties with the law
- Promiscuity / Poor or abusive relationships
- Aggressive, often violent behavior; prone to getting involved in fights
- Inability to tolerate boredom
- Lack access to own feelings and emotions
- Not good at detecting emotions (especially fear) in others
- Reduced empathy
- Severe disruption in moral behavior
What are characteristics of a psychopath?
- Callousness, manipulativeness, glibness and superficial charm
- Often (highly) intelligent
- Grandiose sense of self-worth
- Faking normal emotions: appearance of normalcy and mask of sanity
- Seemingly charming
- Often seems to function normal in society
What makes Antisocial Personality Disorder (ASPD) different from a psychopath?
In ASPD, there’s more pronounced poor behavioral controls, like the inadequate control of anger and temper. They’re often more rude, aggressive, abusive and show angry behavior, compared to a psychopath.
In the first study discussed in the lecture, two things were studied. The first being whether there was any damage to white or grey matter in patients with ASPD. What was the other?
Measuring autonomic nervous system (ANS) functioning. It was already known that ASPD patients showed less emotion, so they wanted to see how the ANS would react to certain stressors by measuring heart rate and skin conductance.
What were the results of the first study when they looked at the grey and white matter of the prefrontal cortex of ASPD patients? Can this result be explained?
The gray matter volume of the PFC was slightly reduced in patients with ASPD. This can be explained by the fact that ASPD patients have less impulse control and the PFC is important for impulse control. So a reduction in gray matter volume of the PFC could explain this.
What was the result of the first study where they measured autonomic nervous system (ANS) activity during a stress test?
The heart rate and skin conductance of people diagnosed with ASPD was clearly reduced.
Name brain areas that:
- are impaired only in ASPD
- are important only in moral decision-making
- are impaired in ASPD and important in moral decision-making
- Impaired in ASPD (red) → anterior cingulate (part of limbic system), temporal lobes, hippocampus, prefrontal cortex and amygdala.
- Important in decision-making (green) → posterior cingulate, prefrontal cortex and amygdala
- Impaired in ASPD and important in moral decision-making (yellow) → prefrontal cortex, amygdala, angular gyrus, superior temporal gyrus
What structures are impaired in rule-breaking behavior?
Prefrontal cortex, amygdala and angular gyrus. These structures are important for moral cognition and emotion.
What is an important structure that is impaired in ASPD or psychopaths? And how is it impaired?
The amygdala, there’s significant reduction in volume and activity.
What’s an important structure that is impaired in antisocial behavior and how is it impaired?
Prefrontal cortex is impaired, it displays robust structural and functional deficits.
What kind of technique is used to study moral decision making in psychopaths where we want to know if their behavior results from deficiencies in moral neural circuits?
functional MRI (fMRI) is used
17 subjects with varying degrees of psychopathy were asked for their judgements on 10 moral dilemmas during fMRI. What results were found?
That subjects with higher psychopathy scores, had a reduced amygdala activity during moral decision making.
What role does the amygdala have in regard to fear?
It’s important in regulation of emotions, where fear is a very important one. The amygdala does not only play a role in regulating fear, but is also important in recognising fear in others.
What else does a reduced amygdala size and activity lead to?
Besides, having less fear and not being able to recognize fear in others:
- reduced amygdale response to fearful photos
- Not good at detecting emotions (especially fear), in others’ voices or facial expressions
- Poor fear conditioning
- Unusually high disgust threshold, tolerating repellent smells and images
- Reduced empathy
ASPD patients having an unusually high disgust threshold, tolerating repellent smells and images, is not a consequence of reduced amygdala activity. What other brain region is responsible for this (and thus impaired in ASPD)?
It’s due to a reduced insula functioning.
What question is important to answer in regard to psychopaths and empathy?
- Do psychopaths lack the ability to emphasize?
Or
- Do they lack the propensity to emphasize?
The question whether psychopaths are either unable to empathize, or simply less likely to empathize in certain situations was researched. Here, psychopaths were asked to watch a movie. First they were told to just watch the movie and then they were asked to try to feel what the victim in the movie felt. What was found?
- When told to just watch the movie, psychopaths showed reduced empathy.
- When told to try to empathize with the victims in the movie, psychopaths were able to empathize.
What is the benefit of being able to empathise with others and what is a disadvantage?
- Benefit → being able to sense the inner states of other helps us to improve the capacity to predict and adapt to the behavior of others.
- Disadvantage → always exercising this is costly when you motivate others, while it depletes your own resources.
What two lines of evidence are there for the neurodevelopmental basis of antisocial behavior?
- Fear conditioning research
- Cavum spetum pellucidum (CSP) marker of limbic maldevelopment
What is fear conditioning?
It’s learning based on fear, where the amygdala associates fear with a previously neutral stimulus.
Here, for example antisocial acts are linked with negative consequences (punishment, social exclusion). In this way, we hope that antisocial behavior can be prevented.
So what happens if fear conditioning fails (in regard to linking antisocial acts with negative consequences)? And what does this say about the neurodevelopment basis of antisocial behavior?
Failure of fear conditioning leads to failure in social learning, which causes the person the be predisposed to antisocial behavior.
It tells us that if poor fear conditioning is a causal role in crime, changes in the brain should be detectable before antisocial behavior manifests.
An experiment is performed where they looked into association of poor childhood fear conditioning and adult crime. How was poor fear conditioning performed?
Here, the goal is to condition/evoke fear with the use of a neutral stimulus.
In the beginning of the fear conditioning, the neutral stimulus is paired with an aversive stimulus/unconditioned stimulus (unpleasant loud noise). This loud noise results in an unconditioned electrodermal response.
Here, first the neutral stimulus is given for about 12 seconds and after this the uncondtioned stimulus is given. When this is repeated several times, this results in an electrodermal response as a consequence/result of the neutral stimulus (because the children know this precedes the aversive stimulus).
An experiment is performed where they looked into association of poor childhood fear conditioning and adult crime. After the poor childhood fear conditioning, children were followed for 20 years. What was the outcome and the connection between poor fear conditioning and adult crime?
That there’s a connection between poor childhood fear conditioning and adult crime. It seems that the children that showed less electrodermal response to the fear conditioning during childhood (age 3), were more likely to have a criminal record in adulthood and were much less influenced by a reinforced stimulus.
What does poor fear conditioning in early life implicate?
Amygdala dysfunction
What is the septum pellucidum and what is the cavum septum pellucidum?
- Septum pellucidum → thin membrane seperating the lateral ventricles (originates from fusion of two leaflets)
- Cavum septum pellucidum → fluid filled cavum inside two fused leaflets of septum pellucidum
The cavum septum pellucidum can be clearly visualized during a MRI and so it can be used as a marker. For what is it used as a marker?
As a marker for fetal limbic maldevelopment. The cavum should close and the leaflets should fuse around week 20 of gestation, if this doesn’t happen it reflects maldevelopment of the midline limbic structures.
What causes cavum septum pellucidum?
Many factors, among others prenatal alcohol exposure.
So as cavum septum pellucidum (CSP) is a neurodevelopmental marker for limbic maldevelopment, they tested whether CSP is linked to antisocial personality disorder (ASPD) and psychopathy. What was found?
Patients with a CSP had a higher chance of having ASPD or psychopathy. They were also involved in more charges and convictions.
So what can be concluded based on the fact that individuals with cavum septum pellucidum (CSP) have higher chances of developing ASPD or psychopathy?
That early brain maldevelopment of limbic structures predisposes to antisocial behaviors.
True or false:
A person with cavum septum pellucidum (CSP) and poor fear conditioning is destined to develop psychopathy or anti-social personality disorder (ASPD).
False, poor fear conditioning and CSP are only predisposing factors. They cannot be used to predict future behavior.
What’s another limitation of the studies that looked at poor fear conditioning and cavum septum pellucidum (CSP)?
That associations are measured at group level, so it can not be used for diagnostics or screening tools in individuals.
What are other (environmental) risk factors for antisocial personality disorder (ASPD) and/or criminal behavior?
Factors affecting brain development during prenatal and early postnatal periods:
- Stress during pregancy
- Birth complications
- Prenatal alcohol or nicotine use
- Prenatal malnutrition
- Early postnatal malnutrition
- Failure to bond to caregivers
- Childhood maltreatment
- Traumatic head injury
- Parental neglect / inconsistent parenting
- Poverty
- Malnutrition
Is antisocial behavior or criminal behavior heritable?
Yes, twin studies suggest that the heritability for antisocial behavior is 40-50%. This means that 40-50% of the variance in ASPD-symptoms can be explained by the variance in genes.
What are genetic risk factors for criminal or antisocial behavior?
- Male sex (testosterone levels)
- Low activity of MAO-A, DAT1, D4D-7R
Childhood maltreatment is a universal risk factor for antisocial behavior, but there are large differences between children in their response to maltreatment. What could be an explanation for this?
That genetic factors play a role in the response to maltreatment, like MAO-A gene.
Describe the characteristics of the MAO-A gene.
Mono Amine Oxidase (MAO-A) is an enzyme that breaks down serotonin, dopamine and noradrenaline. MAO-A has two gene polymorphisms, one with low gene activity and one with high gene activity.
What is the relation between one of the variants of MAO-A, maltreatment and antisocial behavior (based on an important study performed by Caspi et al.)?
It is seen that children with the low MAO-A activity variant are more prone to antisocial behavior, compared to the children with high MAO-A gene activity.
Note: when there is no or probable maltreatment, it doesn’t matter which of the two variants you have. It’s mostly important for when there’s severe maltreatment.
Just study this picture, it supports the fact that there’s gene-environment interaction when you have the low MAO-A gene activity and are severly maltreated.
Ok
What does this picture show us?
That there complex gene-environment interaction for antisocial behavior.
Elaborate on the question whether psychopathic tendencies are always a bad thing.
Some characteristics of a psychopath are: remorseless, charming, concentration, callousness, daring, risk taking, influencial/manipulative and propesity for empathy.
It’s possible that little amounts of these characteristics, could be advantageous for e.g. certain jobs (CEO, soldiers, fire department, surgeons etc.)
It’s also seen that in certain proffesions, psychopaths are more prevalent, such as in corporate professions. Here, psychopathy was positively associated with in-house rating of charisme/presentation style, but negatively associated with rating of responsibility/performance.
