psychopathology Flashcards
psychopathology
generally defined as mental illness
schizophrenia
Generally thought to be from a disease of the brain, but much more still to be understood
Considered a chronic condition that cannot be cured, but can be managed
- Accounts for half of all admissions to psychiatric hospitals
Often manifests in late adolescence or early adulthood; requires clinical management from that point forward
Approximately 1 in 200 people affected at any given time
symptoms and features of schizophrenia
Diagnosis based on observable behavioral and psychological features
Diagnostic criteria include at least 2 of the following lasting for at least one month in duration:
hallucinations
delusions
disorganized speech
grossly disorganized or cataonic behaviour (disrupts a persons behaviour of the world around them)
negative symptoms
positive symptoms of schitzophrenia
excesses or distortions of normal behavior
E.g., presence of hallucinations, delusions, and disorganized thought
negative symptoms of schitzophrenia
the absence of normal behavior
E.g., apathy (lack of motivation), flattened affect (lack of emotional responsiveness), failures of volition or self-directed behavior
Associated with a poorer prognosis and are less easily treated
enlargement of the ventricles in schitzophrenia
Enlargement of the lateral and third ventricles is one of the first-noted and most reliable pieces of evidence
Larger ventricles reflect brain atrophy
Brain atrophy can continue up to 20 years after diagnosis
studying schizophrenia
Two main cognitive neuroscience approaches:
- Comparing cognitive deficits in schizophrenia to deficits in patients with known brain damage.
- Using neuroimaging and brain functioning measurements to identify areas of difference between schizophrenics and control groups.
Both demonstrate involvement of the frontal and temporal lobes.
frontal lobe disruption
Many cognitive functions disrupted in schizophrenic patients are dependent upon the frontal lobe:
Working memory
E.g. Activity is abnormal in the dorsolateral prefrontal cortex when manipulating held information, the ventrolateral prefrontal cortex is underactive during the encoding phase of working memory
Self-monitoring
E.g. Abnormalities in structure and function of medial regions of the frontal lobe including ACC, Abnormal ERN responses to errors
Attention
E.g. Deficient smooth-pursuit eye-movements, fail to activate the frontal eye fields as much as controls
Cognitive control
E.g. frontal lobe mechanisms involved in inhibiting behavior are disrupted
Behavioral flexibility
E.g. impaired on tests of planning and tests of mental flexibility
hypofrontality in schizo
Frontal hypoactivation is evident in schizophrenia both when the person is quietly resting and when engaged in tasks that normally activate the frontal lobe.
temporal lobe disruption in schizo
Reduced volume of gray matter in the left and right middle temporal gyrus, left posterior superior temporal gyrus, and left angular gyrus
Sensory gating effect for auditory stimuli is absent or substantially reduced
Abnormalities in semantic priming (linked to temporal lobe processing):
ERP component sensitive to the degree of semantic relatedness between items (reduced when the target word is semantically related to the prime) do not differentiate as well between concepts that are highly related versus unrelated.
genetic link to schizo
The risk of developing schizophrenia depends on relatedness to someone with the disorder.
Linked to schizophrenia:
Genes related to synaptic pruning during development, immune function, dopaminergic transmission or glutamate function, and more
treatment of schizo
Most common form of treatment – antipsychotic drugs that affect the dopamine systems of the brain (especially D2 dopamine receptor):
Effective in reducing positive symptoms
Relatively ineffective at reducing negative symptoms
Can have unwanted side effects
depression
One of the most common mental illnesses
Impacts around 1 in 10 adults within any 12-month period
Twice as common in women than in men
Timing in relation to life stressors
First episode of is often tied to a severe life stress, such as bereavement or job loss
Subsequent episodes may appear to be decoupled from discrete life stressors
symptoms of depression
In general, depression is a mood disorder characterized by:
Chronic feelings of sadness and hopelessness
Loss of interest or pleasure in once pleasurable activities
Other common symptoms include:
Change in appetite and/or sleeping patterns
Low energy
Low self-esteem
Poor concentration and difficulty making decisions
Suicidal thoughts
subtypes and variations of depression
Subtypes of depression depend on factors such as severity of symptoms, onset, etc. Some of the more well-recognized are:
- Major Depression (main focus in class)
- Dysthymia
- Seasonal depression
- Bipolar disorder (technically in a separate diagnostic category)
cognitive characteristics of depression
Memory and attention are biased toward negative events and interpretations (creating a self-perpetuating cycle)
Poor performance on standard tasks of executive functions
Trouble shifting mental sets (reduced activity in the DLPFC and dorsal anterior cingulate cortex)
Inability to respond adaptively to performance errors or negative feedback (disruption in functional connectivity between cingulate and DLPFC regions)
Poor performance on spatial tasks that depend on the right hemisphere
disruptions during emotional regulation
A. Instruction to regulate emotions does not increase activity in DLPFC
B. During emotion regulation, there is no heightened functional connectivity between the DLPFC and the amygdala
C. Effects of prior emotional regulation upon subsequent amygdala response was absent
subgenual cingulate cortex
Highly interconnected with other regions involved in emotion
May be especially related to the somatic and vegetative symptoms of depression
Shows increased activity in depressed compared to non-depressed people
Activity decreases when therapeutic interventions (e.g., antidepressant drugs or electroconvulsive therapy) are effective
therapeutic interventions
Both cognitive therapy and antidepressant medication are relatively effective for many people.
Cognitive therapy: client works to identify and alter self-defeating and pessimistic thoughts
Antidepressant Drug treatment: affects the monoamines (serotonin, norepinephrine, or dopamine)
- Antidepressants reduce the amygdala’s response to negative information, while increasing PFC’s responses
novel treatments for depression
Used for treatment-resistant depression:
A. Repetitive transcranial magnetic stimulation: magnetic coil over DLPFC alters activity of the brain below the coil
B. Deep brain stimulation: subgenual anterior cingulate cortex is stimulated by electrodes within the brain (very invasive procedure)
C. Vagus nerve stimulation: device placed in the chest cavity stimulates the vagus nerve as it enters the brain
anxiety disorders
5–20% of the population affected at any given time.
Anxiety disorders are more common among women than men.
Depression and anxiety are often comorbid.
There are many types of anxiety disorders, involve nervousness and fear that interferes with daily life.
diagnostic categories of anxiety ddisorders
Phobias
Panic disorder
Posttraumatic stress disorder (technically in a separate diagnostic category)
Generalized anxiety disorder
Obsessive-compulsive disorder
These differ in the object, cause, and manifestation of the fear.
phobias
Fears centered on specific objects or situations,
E.g., spiders, closed spaces, or social settings
Irrational and interfere with normal functioning
panic disorder
Involves repeated panic attacks
Sensations of extreme bodily hyperarousal, dizziness, shortness of breath, elevated heart rate, and a sense of losing control
posttraumatic stress disorder (PTSD)
Clear origin of a deeply traumatic experience such as combat, assault, torture, a natural disaster, or other life-altering experience.
Symptoms include extremely vivid and intrusive recollections of the traumatic situation, avoidance of situations related to that experience, chronically elevated bodily arousal, and feelings of survivor guilt and suicidal thoughts.
generalized anxiety disorder
Free-floating and chronic experience of anxiety, not tied to any specific triggering event or object
obsessive-compulsive disorder (OCD)
Obsessive thoughts
Engages in repeated, compulsive actions intended to ward off a negative outcome
emotional stroop task
Cognitively, individuals with anxiety have exaggerated attentional bias to threatening information in the world.
Emotional Stroop task
Identify the ink color of words
Anxious people slower naming ink color of emotionally threatening words because attention automatically captured by word’s emotional meaning
dot probe task
Cognitively, individuals with anxiety have exaggerated attentional bias to threatening information in the world.
Dot probe task
Indicate the presence of a dot flashed on a screen
Anxious people respond faster when dot appears in location where a threatening word appeared, indicating attention shifted to the threatening word
anxiety and the amygdala
Amygdala functions relevant to anxiety:
Crucial for the acquisition of learned fears
Provokes the body’s fight-or-flight response to stimuli
Directs attention to emotionally salient or urgent stimuli
Activity in the amygdala increases when anxious people are confronted with their fear-inducing triggers and in times of uncertainty.
anxiety and the frontal lobe
Parts of the frontal lobes involved with:
Emotion regulation: Regions exert top-down control over subcortical emotion structures (ex. amygdala)
Fear extinction: Reduced activation of the vmPFC in anxious people leads to difficulty remembering that feared situations are actually safe
Self-monitoring: Overactive ACC reflects increased emotional salience of actions
Controversial therapy: cingulotomy
verbalization and worry
Anxious apprehension (worry) is typically a verbal process, implicating the left frontal region (which generates speech)
Appears inconsistent with approach-withdrawal model of frontal lobe asymmetry (left frontal involvement in approach emotions)
fMRI data resolve this inconsistency:
A region in left inferior frontal gyrus is more activated in worriers.
A left dorsolateral frontal region is more active for positive vs. negative words, consistent with approach-withdrawal model.
posterior regions and anxious arousal
Anxious arousal (panic) associated with right-hemisphere systems governing attentional vigilance and autonomic arousal.
Experiences of heightened anxious arousal or panic activate the posterior right hemisphere.
e.g., among people who scored high on a measure of anxious arousal, or panic, a region of the right inferior temporal gyrus became activated by negative words.
action systems in OCD
Circuits that initiate and inhibit actions may be disrupted in obsessive-compulsive disorder (OCD).
Disruptions in control loops that link orbitofrontal cortex with the basal ganglia
- Basal ganglia appear to have increased activity
- Orbitofrontal cortex also shows abnormalities
Imbalance between systems supporting habitual action (basal ganglia), and those supporting goal-directed action (frontal)
substance abuse and addiction
In any 12-month period, 5-10% of Americans grappling with substance use disorders
Defining feature of abuse:
Unable to control drug-seeking behavior even when consequences are severe; desire for drug outweighs consequences
Two main brain systems have been related to drug abuse:
Dopaminergic reward pathways
Orbitofrontal cortex
addiction and reward pathways
Most drugs of abuse appear to activate the reward pathways that stretch from the midbrain to the nucleus accumbens in the basal forebrain.
Long-term changes in neurons within the reward system in response to the ongoing presence of the drugs.
addiction and orbitofrontal cortex
The orbitofrontal cortex (OFC) is important in generating expectancies about the outcomes of behavior which guide decision making.
Research shows that the OFC region is dysfunctional in addicts.
Substance-dependent individuals perform poorly on gambling tasks that involves learning consequences of choices.
addiction changes and the brain
Changes in dendritic spine density following chronic exposure to amphetamines
other bran regions implicated in addiction
Insula
Amygdala
ACC
DLPFC
Reinforces major cognitive neuroscience theme:
Pathology may be best understood as disrupted relationships among interacting brain areas, rather than simple under-activations or over-activations in certain areas
psychopathy
“Psychopath” is not an official diagnosis. It is an informal term often used for antisocial personality disorder (ASPD).
Characterized by shallow emotional responses, lack of empathy, disregard for others, impulsivity, and an increased likelihood for antisocial behavior (behavior that conflicts with social norms).
ASPD is more common in men than women.
psychopathy diagnosis
In order to receive a diagnosis of ASPD, a person must show a pattern of disregard for and violation of the rights of others. This is indicated by three or more of the following criteria, according to the DSM-5:
failure to conform to social norms concerning lawful behaviors, such as performing acts that are grounds for arrest
deceitfulness, repeated lying, use of aliases, or conning others for pleasure or personal profit
impulsivity or failure to plan
irritability and aggressiveness, often with physical fights or assaults
reckless disregard for the safety of self or others
consistent irresponsibility, failure to sustain consistent work behavior, or honor monetary obligations
lack of remorse, being indifferent to or rationalizing having hurt, mistreated, or stolen from another person
psychopathy reasons
Dysfunction in both amygdala and prefrontal cortex regions including orbitofrontal cortex (OFC)
Studies have shown reduced brain volume in these areas
Reasons for this dysfunction remain unknown
Some genetic contribution: research estimates that between 38 and 69 percent of cases may be hereditary
Environmental contribution: triggers may include childhood neglect, abuse, and/or other adverse experiences
Psychopathy is notoriously resistant to treatment, therapeutic intervention and rehabilitation strategies often prove to be ineffective
