2- An Integrative Approach To Psychopathology

Causes of Psychopathology An Integrative Approach to Psychopathology Chapter 2a

One-dimensional Model • Linear model • Traces the origins of psychopathology to a single cause • Not accepted anymore by most scientists and clinicians – Note that though behavioral types tend to conceptualize most psychopathology as explained by conditioning or learning, they rarely (if ever) ascribe to a linear model

Multidimensional Model • Systemic and often interdisciplinary • Feedback loop which has many independent inputs that disappear into and become part of the whole • Psychopathology is the product of the complex interactions between multiple factors and cannot be considered in an isolated context

• • • • • •

Stress/ Trauma Physical/ Medical Emotional/ Behavioral Developmental Social/ Family Cognitive/ Academic

One-dimensional Model Stress/ Trauma Physical/ Medical

or

Emotional/ Behavioral

or

DISORDER

or Developmental or Social/ Family

or Cognitive/ Academic

Multidimensional Model Physical/ Medical Stress/ Trauma

Emotional/ Behavioral DISORDER Social/ Family

Developmental Cognitive/ Academic

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Genetic Contributions to Psychopathology • Since 19th century we have known that genes are (at least partially) responsible for our physical characteristics – height, hair and eye color

• Although other factors might also affect physical appearance, our genes determine the boundaries of our potential

The Nature of Genes • DNA is in the shape of a double helix (spiral staircase) • Chromosomes (Greek: chroma- color, soma- body) are singular structures of organized DNA • Humans have 46 chromosomes (23 pairs)

Genes • Long chains of deoxyribonucleic acic (DNA) molecules located at various chromosomal sites within the cell nucleus • Basic physical units of heredity • Unique in everyone except for identical twins

The Nature of Genes • Problems sometimes develop when the normal contingent of 46 human chromosomes (arranged in 23 pairs) is disturbed – Down's syndrome or trisomy 21, is caused by an extra chromosome on the 21st pair

– The last pair are the sex chromosomes

The Nature of Genes

The Nature of Genes

• Mistakes from copying or ordering genetic material may or may not result in defective mutations

– Mendelian laws of genetics uses (simple) probability to determine how many offspring will inherit a trait or disorder – However most traits or disorders (i.e. IQ) are polygenic, or minimally determined by a multitude of genes

– Dominant gene mutations will result in a particular trait – Recessive gene mutations have to be paired with other recessive genes to be expressed

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The Nature of Genes • Genes are also multifunctional, meaning they can be responsible for more than one trait or disorder • Today we use quantitative genetics which specify which group of genes affect a trait, but doesn’t specify which genes are responsible for what effects

The Interaction of Genetic and Environmental Effects • Eric Kandel stated that the process of learning may change the genetic structure of cells • Dormant genes might be activated by environment even after maturation

Diathesis – Stress Model • A combination of inherited tendency (vulnerability) and specific stressful conditions are required to produce a disorder

New Developments • Estimate for genetic contribution personality traits and cognitive abilities in humans is about 50%. – No individual genes have been identified relating to any major psychological disorder

The Interaction of Genetic and Environmental Effects • Meaning that our brains, bodies, and genes have plasticity which allows us to adapt but also leaves us open to developing diseases – Neuroplasticity or Cancer

Reciprocal Gene – Environment Model • Genetic predisposition for a disorder also increase our probability of creating stressful life events that promote the disorder Stress

Genetics

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Nongenomic Inheritance of Behavior • Several studies (Crabbe et al. 1999, Francis et al. 1999) have found that despite genetic endownments, behavior can be inherited through environment • Ideas and behavior can be passed on by example • In conclusion, nature vs. nurture debate rages on

Neurons • The brain uses nerve cells, called neurons, to send signals that control every thought and action • The brain contains an average of 140 billion neurons

Neurons • Neurons operate electrically, but communicate with other neurons chemically • They communicate in synaptic cleft, a space between nerve cells • The chemical messengers, called neurotransmitters, are sent from one neuron to the other

Neuroscience and Its Contributions • Neuroscience focuses on understanding the role of the nervous system in disease and behavior • To understand how the brain works we have to look at its parts

Neurons • The typical neuron contain a central cell body with two kinds of branches • The dendrites, extend from the cell body to receive chemical messages from other nerve cells, which are converted into electrical impulses • The axon, transmits these impulses to other neurons

Neurons • Major neurotransmitters implicated in psychopathology include norepinephrine (or noradrenaline), serotonin, dopamine, and gamma aminobutyric acid (GABA). • Excesses or insufficiencies will result in different kinds of psychopathology

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Neurons • The brain is like an electrical system, neurotransmitter currents run on circuits, or specified paths, however those paths often intersect • Almost all drug therapies work by either decreasing or increasing the flow of specific neurons in these circuits, unfortunately alterations can have large scale effects

Divisions of the Nervous System • The peripheral nervous system works in coordination with the brain stem to ensure proper bodily functioning and consists of the – Somatic nervous system controls muscles and movement – Autonomic nervous system (ANS) regulates the cardiovascular system, endocrine system (e.g., pituitary, adrenal, thyroid, and gonadal glands) and aids in digestion and regulation of body temperature.

Divisions of the Nervous System • The endocrine system produces its own chemical messengers (i.e., hormones) and releases them directly into the bloodstream. – Adrenal glands produce epinephrine (also called adrenaline) in response to stress, including salt-regulating hormones. – Thyroid produces thyroxine, which facilitates energy metabolism and growth. – The pituitary is the master gland that produces several regulatory hormones – The gonads produce sex hormones (e.g., testosterone and estrogen).

Divisions of the Nervous System CNS (Interneurons) Brain and Spinal Cord tissue

Human Nervous System

PNS (Sensory and Motor) All other nervous

Somatic Nervous System Voluntary Input: Sense Organs Output: Skeletal Muscles

Autonomic Nervous System Involuntary Input: Internal Receptors Output: Smooth Muscles and Glands

Sympathetic Motor System System “fight or flight” responses Neurotransmitter: Noradrenaline “Adrenergic System”

Parasympathetic Motor relaxing responses Neurotransmitter: Acetylcholine “Cholinergic System”

Divisions of the Nervous System • Autonomic nervous system (ANS), is divided into the sympathetic and parasympathetic nervous systems – The sympathetic nervous system mobilizes the body (e.g., increases heart rate) during periods of stress or danger and is part of the emergency or alarm response. – The parasympathetic nervous system renormalizes arousal and facilitates digestion.

Divisions of the Nervous System • The endocrine system is closely related to the immune system and is implicated in anxiety, stress, and sexual disorders • The hypothalamic-pituitaryadrenalcortical axis (HPA axis) illustrates the connection between the nervous and endocrine systems, and is implicated in several forms of psychopathology.

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Structure of the Brain

Structure of the Brain

• The brain is divided into two parts. – The lower brain stem is the most primitive part and is responsible for most of the automatic functions necessary for survival (e.g., breathing, sleeping, moving) – The more advanced brain systems are located in the forebrain.

Lower Brain Stem

Lower Brain Stem •

The hindbrain contains the medulla, pons, and cerebellum (motor coordination) – These structures control activities such as breathing, heartbeat, and digestion.

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The midbrain coordinates movement with sensory input and contains parts of the reticular activating system (RAS) – The RAS contributes to arousal, tension, and waking and sleeping.

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At the very top of the brain stem (i.e., above the hindbrain) lies the diencephalon, which contains the thalamus and hypothalamus – Transmit information to the forebrain and are integral to behavior and emotion.

Forebrain • •

At the base is the telencephalon, which contains limbic system (Limbic - border) This includes Hippocampus (sea horse), cingulate gyrus (girdle), septum (partition), and amygdala (almond). –

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Emotional expression, impulse control, sex, aggression, hunger, and thirst are controlled by this part of the brain

Another area at the base of the forebrain is the basal ganglia, including the caudate (tailed) nucleus. –

Motor behavior is controlled by this area, and damage can cause twitching or shaking

Forebrain • The largest part of the forebrain is the cerebral cortex, which contains over 80% of the neurons in the CNS – Reasoning and creative skills are derived from this brain area

• The cerebral cortex is divided into two – Left hemisphere appears to be responsible for verbal and cognitive processes – Right hemisphere appears more responsible for spatial abilities

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Neurotransitters An Integrative Approach to Psychopathology Chapter 2b

• Brain circuits are pathways of neurotransmitters. • Neurotransmitters do not necessarily have a specific receptor • After a neurotransmitter is released, it is quickly drawn back via reuptake process.

Neurotransmitters • Drug therapies are either

Serotonin (5HT) • Serotonin (5-HT)

– Agonists

– Regulatory Neurotransmitter – Information processing – Coordination of movement – Inhibition – Regulation of appetite and eating behavior – Sexual and aggressive behaviors – Mood regulation

• Increase flow (agonists) • Mimic effects (agonists)

– Antagonists • Decrease flow • Block receptors

– Inverse Agonists • Increase competing biochemicals that deactivate/cancel out neurotransmitter

Serotonin (5HT) • Serotonin (5HT) is concentrated in the midbrain and connected to the cortex – Widespread effects on behavior, mood, and thought processes.

• Tricyclic antidepressants (e.g., imipramine) and new classes of serotonin specific reuptake inhibitors (SSRIs; e.g., Prozac) affect the serotonergic system (see also St. John’s-wort).

Serotonin (5-HT) Deficiency • • • •

Less inhibition Instability Impulsivity Tendencies to overreact to situations (e.g., aggression, suicide, impulsive overeating, excessive sexual behaviors

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Gamma aminobutyric acid (GABA) • Reduces overall arousal – Tempers anger, hostility, aggression – Reduces excessive anticipation – Stabilizes positive and negative emotional states

Gamma aminobutyric acid (GABA) • Reduces postsynaptic activity, thus, inhibits several behaviors and emotions, particularly anxiety • However, effect is not specific to anxiety • Benzodiazepines make it easier for GABA to attach to specialized receptors

Norepinephrine (Noradrenaline or NE)

Norepinephrine (Noradrenaline or NE)

• Regulatory Neurotransmitter in CNS and PNS • Controls HR, BP, and Respiration • Triggers “Alarm” Responses • Energy • Emotions • Attention and concentration • Memory • Speed of information processing

• Regulatory Neurotransmitter in CNS and PNS • Also part of the endocrine system • Stimulates at least alpha-adrenergic and beta-adrenergic receptors. • Beta-blockers for hypertension reduce the surge in norepinephrine and keep heart rate and blood pressure down.

Norepinephrine (NE) Deficiency

Dopamine (DA)

• • • • • •

Poor attention Problems concentrating Deficiencies in working memory Slowness of information processing Depressed mood Fatigue

• Activating Neurotransmitter • Acts on the “Reward Pathway“ – Aids in Exploratory and Pleasure seeking behaviors

• Opposite of Serotonin – DA and 5HT circuits cross at many points and seem to balance one another

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Dopamine (DA) • May act by "switching on" various brain circuits that inhibit or facilitate emotions or behavior • Has been implicated in schizophrenia • Reserpine (an antipsychotic) blocks specific dopamine receptors • L-DOPA (for Parkinson’s) is a DA agonist

Behavioral and Cognitive Science • The development of psychological disorders has been traced to – Neuroanatomy and function – Psychosocial influences on how humans and other animals acquire, process, store, and retrieve information

• Modifying the brain circuitry through – Biological treatments (changing hardware) – Psychosocial treatments (changing software)

Conditioning and Cognitive Process • Robert Rescorla expanded on Pavlov’s Classical Conditioning experiments – Learning • Complex variety of judgments and cognitive processes • Measured the meaningfulness of relationships between events and environment • Response maximized benefit or at least minimized harm

Neurotransmitters • Dopamine (DA) Deficiency – Parkinson’s Disease – Tardive Dyskinesia DA Side-effect

• Dopamine (DA) Excess – Schizophrenia – Addictions

Behavioral and Cognitive Science • Interaction of Psychosocial Factors with Brain Structure and Function – Experience may produce richer, more plastic neural connections in the brain which determines vulnerability to psychological disorders later in life – Neurochemical substances have very different effects depending on the psychological histories of the animals

Conditioning and Cognitive Process • Martin Seligman – Learned Helplessness • Depression stems from attribution to an external locus of control • Give up attempting to cope

– Learned Optimism • Optimism stems from attribution to internal locus of control • Function better, psychologically and physically, in the face of considerable stress

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Conditioning and Cognitive Process • Albert Bandura – Modeling

Conditioning and Cognitive Process • Morris et. al. – Prepared Learning

• Observation or Imitation of other individuals • Symbolic integration of others’ experiences • Judgments about the consequences of similar behavior to oneself • Careful analysis of cognitive processes can lead to scientific predictions about behavior

• We are genetically endowed with the fear of certain types of objects or situations which proved dangerous to our ancestors – Snakes, bugs, heights, bodily fluids

• Evolution has paired certain stimuli together because it promotes adaptive behaviors

– Social context of learning

Emotions • Emotions are short-lived, temporary states that are responses to external events • Has three overlapping components – Behavior • Freeze, escape, attack • Communicative tool

– Physiology • Primitive brain areas • Allows emotional processing with higher cognition

– Cognition • Appraisals and attributions

Emotions • Not to be confused with Mood, which is a more persistent period of emotionality – Mood disorders

• Or Affect, which is the momentary emotional tone that accompanies what we say or do – Facial expression or body language

• Emotions can have physical effects which is studied in the field of Health Psychology

Emotions • The Purpose of Emotions – Motivates us to carry out a behavior – Communicates our experiences • Fear – Fear activates the emergency survival responses “fight or flight” – Affect of fear lets others know that there is danger

• Psychopathology arises in over - or under - expression of emotion

Cultural, Social, and Interpersonal Factors • Psychopathology can be associated with certain – Cultures • Haitian Voodoo or Malay “amok”

– Genders • Phobias, Addictions, and Eating Disorders

– Life stages • Different periods of development have different vulnerabilities

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Unconsciousness and Memory • Some other important concepts in cognitive science – Equifinality states that a behavior or disorder may have several different causes – The presence of the conscious and unconscious mind • Implicit - Response but no recollection of events • Explicit memory - Recalling events

Emotions • Not to be confused with – Mood- persistent period of emotionality – Affect- momentary emotional tone that accompanies what we say or do • Facial expression or body language

• Emotions can have physical effects which is studied in the field of Health Psychology

Cultural, Social, and Interpersonal Factors • Psychopathology can be associated with certain – Cultures • Haitian Voodoo or Malay “amok”

– Genders • Phobias, Addictions, and Eating Disorders

– Life stages • Different periods of development have different vulnerabilities

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