neurobiology of psychopathic behavior

Neurobiology of Psychopathic behavior

Subhadeep Dutta Gupta

The lack of baggage and fear

Introduction• The word ‘personality’ refers to the pattern of thoughts, feelings and behaviour

that makes each of us the individuals that we are

• Personality doesn’t change very much, but it does develop as we go through

different experiences in life, and as our circumstances change. So, as we mature

with time, our thinking, feelings and behaviour all change

• Personality disorders (PDs) are considered chronic conditions that emerge in late

adolescence, and typically carry pervasive implications for self- and/or

interpersonal functioning (American Psychiatric Association [APA], 2013; Skodol,

2012)

Classification of Personality Disorders:

Historical Overview:

• First described a group of patients afflicted

with mania sans délire (insanity without

delirium)

• The term was used to describe individuals

who had no intellectual problems but a

profound deficit in behaviour typified by

marked cruelty, antisocial acts, alcohol and

drug use, irresponsibility, and immorality

Philippe Pinel (1745-1826)

Julius Koch (1841-1908)

• Coined the term psychopastiche, or

psychopath, in 1888

• Koch claimed that psychopathy arose

from a flaw in one’s constitution at birth

Historical Overview:

Diagnostic Criteria for Antisocial Personality Disorder in DSM-V:

1. Failure to obey laws and norms by engaging in behaviour which results in

criminal arrest, or would warrant criminal arrest

2. Lying, deception, and manipulation, for profit or self-amusement

3. Impulsive behaviour

4. Irritability and aggression, manifested as frequently assaults others, or

engages in fighting

5 Blatantly disregards safety of self and others

6 A pattern of irresponsibility and

7. Lack of remorse for actions (American Psychiatric Association, 2013)

Who are Psychopaths?• Conduct disorder is a childhood behaviour disorder that is characterized by

persistent aggressive or antisocial behaviour that disrupts the child’s environment

and impairs his or her functioning – Macdonald Triad

• Psychopathic traits consist of a callous–unemotional component and an

impulsive–antisocial component, which are associated with two core

impairments:

reduced empathic response to the distress of other individuals;

deficits in decision making and in reinforcement learning

• Empathy: ‘‘An affective response more appropriate to someone else’s situation

than to one’s own’’ (Hoffman, 1987)

• Callousness: Omission of caring feelings or behaviours in contexts where others

generally experience those feelings or behaviours

Brain regions associated with experience sharing and mentalizing

-- Nature Neuroscience 15, 675–680 (2012)

Traits of a Psychopath:• repeatedly engages in a wide range of irresponsible, unethical or criminal activities

for personal gain

• has a constant need for stimulation and lacks any realistic long term goals

• lacks empathy or remorse and tends to blame others for his unscrupulous activities

• will appear superficially charming, but also glib and shallow with a grandiose sense

of self-worth

• promiscuous sexual behaviour, many short-term marriages, adultery and so forth

are common

Snakes in suits:• Across all races, cultures and ethnic groups ; Male : Female 4:1

• 1% of general population aged 18 and above and 10-20 % of prisoners

• Most psychopaths as : Least psychopaths as:

• It is twice as common as schizophrenia, anorexia, bipolar disorder, and paranoia

• Recidivism 4-8 times the rate compared to other offenders

CEO

Lawyer

Media (T.V / Radio)

Salesperson

Surgeon

Journalist

Police officer

Care aide

Nurse

Therapist

Craftsperson

Beautician

Charity worker

Teacher

Types:• Primary Psychopathy:

constitutional deficit that leads to callous and manipulative behaviour,

superficial relations, and a lack of negative affect such as guilt, fear or anxiety;

they plan their behaviour and socially rank themselves higher than others

• Secondary Psychopathy:

develops from environmental causes, such as parental abuse or rejection,

resulting in an underlying emotional problem associated with neuroticism,

impulsivity, aggression and emotional reactivity

Evolution of Psychopathy Frequency- dependent selection:

Psychopaths have evolved to take the advantage of the fact that most people

are cooperators

Thus psychopathy represents an alternative strategy that is successful only at a

particular low relative frequency in the population

If there are too many cheaters , non-psychopaths become very vigilant and

cheating opportunities disappear

Theoretical Basis for

Psychopathy

Neurobiological Theory:

Phineas Gage (1823-1860) Gage’s skull and the tamping iron on display at the

Warren Anatomical Museum

Neural underpinnings of empathy & callousness

The Social Brain:• Empathy connects neurocircuitry for social behaviour, physical pain, and the

ability to represent both the self and another

• Functional neuroimaging studies in humans document a Empathy Circuit

including :

Anterior insula

Anterior cingulate cortex

Supplementary motor area

Amygdala

Brainstem

Periaqueductal gray – that responds to the perception of others’ distress

Role of Cortex :

• The prefrontal cortex is an area of the brain that is important for reasoning,

inhibition of behaviour, social emotions, empathy, attention, and executive

functions

Mirror ‘Gandhi/ Dalai Lama’ Neuron System

Orbitofrontal Cortex (OFC)

Ventromedial Prefrontal Cortex (vmPFC)

Anterior Cingulate Cortex (ACC)

-- Nature Medicine 18, 211–213 (2012)

Role of vmPFC:

connecting past decisions or outcomes with new decisions one might be

considering/ contemplating (e.g., pursuing a reward). This includes involvement

in extinguishing past behaviours and learning from experience

strongly associated with assigning value to an action or goal of a certain

behaviour or decision. This assists in the process of making a choice between

different rewards by weighing which would be better

regulating role within the emotional (limbic) system of the brain. Therefore, it is

suspected to be involved in the control or regulation of emotions, notably

negative emotions

enables individuals to adapt their behaviour in response to unexpected rewards

or adversities

enables individuals to anticipate whether some course of action will evoke

positive or negative emotions, both immediately and in the future

when the OFC is activated, individuals choose the courses of action that tend to

be rewarded, rather than punished, by other people

OFC facilitates the Theory of Mind capacity – Affective ToM

Role of OFC:

-- Brain and Cognition 2004 ;55 (1) 198–208

• Unique position in the brain, with connections to both the “emotional” limbic system and

the “cognitive” prefrontal cortex

• empathy for pain activates neural structures that are also involved in the direct experience

of pain—such as the anterior insula and the ACC

• Detection of errors

• Detection of conflicts

• Reward based learning Theory

• Emotional regulation

Role of ACC:

Von Economo neuron Pyramidal neuron

Low activity in depressed subjects

High activity in normal subjects

recollecting sad events

--Principles of Neural Science, 5th Edn

The Psychopathic Brain

Prefrontal lesions can lead to a form of acquired psychopathy

1. Cortical Abnormalities:

Pattern of percent gray matter local difference (left panel) and statistical

significance (right panel) of the cerebral cortex in psychopathy versus controls

-- Psychiatry Research: Neuroimaging 193 (2011) 85–92

Reduced PFC gray matter volume and reduced Autonomic activity in Psychopaths

PFC Gray matter volume Heart Rate

PFC White matter volume Skin conductance

-- Arch Gen Psychiatry 2000 (57), 119–127

vmPFC dysfunction:Focal vmPFC lesions

personality changes (lack of empathy, irresponsibility,

and poor decision making)

Pseudopsychopathy

Uncinate Tract

n = 9 (each group)

p = 0.003

-- Molecular Psychiatry (2009) 14, 946–953-- Developmental Cognitive Neuroscience 14 (2015) 50–61

Reduced Prefrontal Metabolism in Psychopaths

Control Psychopath

Illustration of cortical deficits in one psychopath (right) relative to one control (left)

Prefrontal gyri/occipital ratios for cortical peel technique.

-- Biol Psychiatry 1994 (36) 365-373

n = 22

2. Limbic Dysfunctions:

• Amygdala

• Hippocampus

Amygdala:• Amygdala deals with emotion, memory, fear, anger, and pleasure

• Reward learning, social interaction, and moral emotion and reasoning, where

the ability to recognize the emotions signalled by facial expressions is crucial

for making advantageous decisions in a complex social environment

• Evidence from Kluver – Bucy Syndrome

-- Arch Gen Psychiatry. 2009; 66(9): 986–994

Psychopathic individuals were found to

show bilateral amygdala volume

reductions compared with controls.

n = 86

-- J Abnorm Psychol. 2010; 119(4): 863–874.

n = 16

Positive association between right

amygdala activity and violation severity

ratings present in nonsychopaths

Deformations within the Amygdala in Psychopaths

Regional atrophy in amygdala structure in the vicinity of the basolateral, lateral,

central, and cortical nuclei in individuals with psychopathy

-- Arch Gen Psychiatry. 2009 Sep; 66(9): 986–994

Hippocampus

-- Human Brain Mapping 31:438–447 (2010)

Unsuccessful psychopaths have an exaggerated structural asymmetry

in the anterior hippocampus.

-- Biol Psychiatry 2004;55:185–191

3. Basal Ganglia Dysfunctions:

-- Behavioural Brain Research 169 (2), 2006, 239–247 -- Biol Psychiatry 2010;67(1):52-8

4. Cerebellar Dysfunctions:

Positive regression within prisoners between scores of Factor 1 (PCL-R) and

gray matter volume of the right cerebellar hemisphere.

-- Neuroscience Volume 308, 12 November 2015, Pages 194–201

Control = 40Psychopaths = 37

5. Corpus Callosum

-- Arch Gen Psychiatry. 2003;60(11):1134-1142

Neurochemistry of

Psychopathic Brain

Role of Cortisol and Testosterone:

HPA and HPG maintain an appropriate balance between withdrawing in the presence of

fearful or threatening stimuli, and approaching in the presence of rewarding stimuli

Average salivary cortisol (lg/dl) levels by group and gender

Males Females

16

13

11 15

9

1416

14

-- Journal of Child Psychology and Psychiatry 47:1 (2006), pp 30–36

Testosterone shifts the balance between sensitivity for punishment

and reward in healthy young women

-- Psychoneuroendocrinology, Volume 29, Issue 7, 2004, 937–943

High testosterone/cortisol ratio

communication between emotional (sub-cortical, amygdala) and cognitive (cortical,

OMPFC) systems is diminished

emotional information from the amygdala cannot adequately reach the cortex, and

therefore cannot be used to avert the basic motivational, reward driven

reactions

violence inhibition mechanism doesn't function properly

Salivary α- amylase:

Males scoring low in psychopathy demonstrated a significant increase in sAA

levels following the social stress task whereas individuals scoring high in

psychopathy did not

-- Psychoneuroendocrinology, Volume 54, 2015, 14–23

n = 158

Electrophysiological difference

in Psychopathy

-- Psychophysiology, Volume 28 (3), 1991

Neurogenetics and

Psychopathy

Role of SNAP-25 gene:

MnlI T/T and DdeI T/T genotypes were more frequently present in male subjects with

APD than in controls

-- Can J Psychiatry. 2011 Jun; 56(6): 341–347

MAOA gene is knocked out in mice

highly aggressive, becoming ‘‘knock-out’’ fighters themselves

Knock the gene back in, and they return to their normal behaviour patterns

(Cases et al., 1995)

Role of MAO-A gene:

-- Science 297, 851 (2002)

Summary

Insane isn’t really black or white, we are all pathological, in our own ways