Psychopathology Flashcards
Schizophrenia
> Generally thought to be a disease of the brain, much to be understood
> Considered a: chronic condition (cannot be cured)
> But can be managed
> Schizophrenia amounts to half of all admissions to psychiatric hospitals
> Often manifests in late adolescence/ early adulthood
> Requires clinical management after manifestation
> 1 in 200 people affected in any given time
Symptoms and features of schizophrenia (diagnosis)
- Hallucinations
- Delusions
- Disorganized speech
(one of these must be present for diagnosis)
> Grossly disorganized/ Catatonic behaviour
> Negative symptoms (absence of normal behaviour)
Diagnosis based on observable behaviour and psychological features. At least 2 of the above symptoms must be present for at least one month in duration.
Positive vs. Negative Symptoms
Positive: something is being added, excess or distortion of normal behaviour, presence of symptoms that aren’t normally there
Negative: something is being removed, absence of normal behaviour.
»> apathy, flattened affect, failures of volition or self-directed behaviour
»> associated with a poorer prognosis, less easily treated
Psychopathology
“Mental illness”
- Schizophrenia
- Depression
- Anxiety disorders
- Substance use disorders
Schizophrenia and ventricles
- Enlargement of the lateral and third ventricles is a well-noted piece of evidence for schizophrenia
- Larger ventricles reflect brain atrophy
- Brain atrophy can continue up to 20 years after diagnosis
Approaches in studying schizophrenia
Two main cognitive neuroscience approaches:
1. Comparing cognitive deficits in schizophrenia to deficits in patients with known brain damage
2. 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
Affected:
> Working memory
> Self monitoring
> Attention
> Cognitive control
> Behavioural flexibility
___________
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
Frontal hypoactivation is evident in schizophrenia when the person is resting and when engaged in tasks that normally activate the frontal lobe
Temporal lobe disruption
Reduced volume of grey 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 schizophrenia
Risk depends on relation to someone with the disorder
Linked to schizophrenia
»> Genes relate to synaptic pruning during development, immune function, dopaminergic transmission or glutamate function, and more
Treatment of Schizophrenia
Most common form: antipsychotic drugs that affect the dopamine symptoms 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
» 1 in 10 adults withing any 12-month period
» Twice as common in women than in men - Timing in relation to life stressors
» First episode is often tied to a severe life stress, 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
Major Depression
Dysthymia
Seasonal Depression
Bipolar Disorder
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
Subcortical regions in depression
Overactive amygdala, especially in response to negative information
Subcortical reward pathways are underactive
> Apathy, lack of motivation, anhedonia
> Related to dopaminergic motor symptoms, such as the basal ganglia, may also be implicated in psychomotor slowing
Hippocampus affected by elevated stress hormones
» Smaller and less active in depression
Disruptions during emotional regulation in depression
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:
A. Repetitive transcranial magnetic stimulation, magnetic coil of DLPFC alters activity of the brain below the coil
B. Deep brain stimulation: subgenual anterior cingulate cortex is stimulated by electrodes withing the brain (invasive process)
C. Vagus nerve stimulation: device places in the chest cavity stimulate the vagus nerve as it enters the brain
Anxiety Disorders
- 5-20% of the population affected at any given time
> Anxiety disorders more common among women
> Depression and anxiety are often comorbid
> Many types of anxiety disorders
Diagnostic categories of anxiety disorders
Phobias
Panic disorders
PTSD (technically a separate category)
GAD
OCD
Differ in the object, cause, and manifestation of the fear
Phobias
Fears centred on specific objects and/ or situations
-> Irrational, interferes with normal function
Panic disorder
-> Repeated panic attacks
-> Sensations of extreme bodily hyperarousal, dizziness, shortness of breath, elevated heart rate, and a sense of losing control
PTSD
Clear origin of a deeply traumatic experience such as combat, assault, torture, a natural disorder, or other life-altering experience
Symptoms include vivid and intrusive recollections of the traumatic situation, avoidance of the situations related to that group, chronically elevated bodily arousal, feelings of survival guilt and suicidal thoughts
GAD
Generalized Anxiety Disorder
Free-floating and chronic experience of anxiety, not tied to specific triggering event or object
OCD
Obsessive thoughts
Engages in repeated, compulsive actions intended to ward off a negative outcome
Anxiety and Attention
Individuals with anxiety have exaggerated attentional bias to threatening information in the world
Emotional Stroop task:
> Identify the ink colour of the words
> Anxious people slower naming in colour of emotionally threatening words because attention automatically captured by the word’s meaning
Dot Probe Task
> Indivate the presence of a dot flashed on the screen
> Anxious people respond faster when dot appear in a location where a threatening word appeared, indicating attention shifted to the threatening word
Anxiety and the amygdala
Functions relevant to anxiety
> Curcial 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 fear-inducing triggers and in times of uncertainty
Anxiety and the frontal lobe
Emotional Regulation: regions exert top-down control over subcortical emotion structures (like the 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
Cingulotomy
Controversial therapy for Anxiety
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 associated with right-hemi systems governing attentional vigilance and autonomic arousal
Experiences of heightened panic activate the posterior right hemi
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 behaviour even when consequences are severe, desire for drug outweighs consequence
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 attention of the drugs
Addiction and Orbitofrontal cortex
OFC is important in generating expectancies about the outcomes of behaviour which guide decision making
Research shows that OFC region is dysfunctional in addicts
Substance-dependent individuals perform poorly on gambling tasks that involve learning consequences of choices
Addiction changes in the brain
Changes in dendritic spine density following chronic exposure to amphetamines
Insula, amygdala, ACC, DLPFC also implicated
> reinforced 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
Not an official diagnosis
> ASPD
> Shallow emotional responses, lack of emptathy, disregard for others, impulsivity, increased likelihood for antisocial behaviour (behaviour which conflicts with social norms)
> ASPD more common in men than women
Diagnosis of Psychopathy
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 behaviours, 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 behaviour, or honour monetary obligations
lack of remorse, being indifferent to or
rationalizing having hurt, mistreated, or stolen from another person
Psychopathy and brain dysfunction
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
