PSYC337 Causes of mental disorders

etiology

the study of the causes, origins or reasons behind the wy things are, the way they function, or the causes themselves

problems in oral stage

• alcohol consumption

• smoking

• overeating

• aggressive tendencies

problems in anal stage

• controlling

• perfectionism

• cleanliness obsession

problems in phallic stage

focus on genitals (Oedipus/Electra complex)

problems in latency stage

• immaturity

• inability to develop meaningful relationships

problems in genital stage

• socialization

• lidelong relationships

superego

• type of thinking: conscience

• driven by: moral principles

ego (mediator)

• type of thinking: logical, rational

• driven by: reality principle

id

• type of thinking: illogical, emotional, irrational

• driven by: pleasure principle

reality anxiety

based on real-world threats

neurotic anxiety

emerges from unconscious fears that inner desires might escape control

moral anxiety

arises from conflicts between ego and superego when an individual fails to meet internalized moral standards

unresolved conflicts and traumas from childhood

could manifest as anxiety in adulthood

repressed memories

might surface when triggered, causing heightened anxiety

Little Hans

• 5 year old boy who developed fear of horses

• Freud thought it was related to unconscious anxieties tied to the Oedipus complex, where he felt desire for his mother, jealousy toward his father, and fear of castration

• fears were said to diminish as he gained awareness of his feelings and their symbolic meanings

Freud’a interpretation of Hans’ fear of horses

as displacement of his fear of his father

psychoanalytic perspectives on depression

• early parental rejection could predispose later development of later depression

• unconscious anger toward the lost love object is turned inward leading to self-criticism, guilt, and shame

behaviourist prespectives on anxiety

a learned response to certain stimuli or situations

anxiety as a learned response: classical conditioning

if someone experiences anxiety during a public speaking event, they might start to feel anxious in any situation that reminds them of public speaking

anxiety as a learned response: operant conditioning

if avoiding a social situation decreases your anxiety, you might be more likely to avoid similar situations in the future, reinforcing anxiety response

anxiety as a learned response: observational learning

if a child sees a parent reacting anxiously to certain situations, the child might learn to respond in the same way, especially if those reactions appear to be effective or result in attention or sympathy

behaviourist perspective on depression

depression may result from a decrease in positive reinforcement or rewards from the environment

learning and depression cycle

life events → low levels of positive reinforcement, narrowed behavioural repertoires → sadness, loss of energy, biological symptoms → attempt to cope with symptoms, stay home, miss work, avoid friends, ruminate → depression

cognitive behavioural perspectives on emotional disorder

emotional disorders result from maladaptive thought patterns and behaviours

cognitive model of anxiety

learning experience → danger schemas formed → critical incident → schema activated → negative automatic thoughts → anxiety symptoms → behavioural responses → cognitive biases

anxiety schema

• a mental framework that predisposes a person to experience heightened levels of fear and worry

• those affected often interpret neutral stimuli as threatening, overestimating the likelihood or severity of negative events

the cognitive triad of depression

• negative views about the world e.g., everyone is against me because I’m worthless

• negative views about the self e.g., I’m worthless and inadequate

• negative views about the future e.g., I’ll never be good at anything

biochemical theory of anxiety

anxiety disorders are linked to imbalances or dysfunctions in certain neurotransitters in the brain

serotonin and anxiety

• known for regulating mood, sleep, and appetite

• low levels are often associated with increased anxiety and mood disorders

norepinephrines and anxiety

• often associated with fight or flight response, involved in regulating alertness and arousal

• imbalances can contribute to anxiety symptoms

GABA and anxiety

• an inhibitory neurotransmitter that is critical for reducing neuronal excitability

• low levels can lead to increased anxiety, as it plays a role in calming the brain and nervous system

biochemical theory of depression

the monoamine hypothesis has been the dominant biochemical model of depression

monoamine hypothesis of depression

proposes that depression is caused by a functional deficiency in monoamine neurotransmitters in the brain, specifically serotonin, norepinephrine, and dopamine

serotonin and depression

• low levels are strongly associated with depression

• regulated mood, sleep, appetite, and emotional stability

• deficit in serotonin pathways are often linked to depressive symptoms

norepinephrine and depression

• this neurotransmitter influences arousal, alertness, and energy levels

• reduced activity has been associated with feelings of fatigue and low motivation typical of depression

dopamine and depression

involved in the reward system and motivation, decreased levels can contribute to anhedonia (loss of pleasure), which is common in depression

genetic predisposition of emotional disorders

• emotional disorders tend to run in families, suggesting a hereditary component

• individuals with first-degree relatives who have a disorder are at higher risk of developing similar conditions

heritability of emotional disorders

• research, including twin studies, indicates that emotional disorders have a significant genetic component

• for example, heritability estimates for depression range from about 30%-40%

gene-environment interactions in emotional disorders

• genetic predisposition interacts with environmental factors such as stress, or trauma

• a genetic vulnerability may only manifest as a disorder when triggered by environmental stressors

Hans Selye

• his interest in stress began when he was in medical school

• he had observed that patients with various chronic illnesses like tuberculosis and cancer appeared to simply a common set of symptoms that he attributed to stress

what causes stress according to Hans Selye?

• noted that stress could occur not only in negative situations but also positive ones

• both can tax a person’s adaptational resources, but distress has the potential to do more damage

• can occur in more than one form

can we objectively define stress?

though elements of stress can be objectively defined and measured (temperature, noise, adaptational demands), the experience and impact can vary significantly from person to person, making it a complex and multidimensional construct

diathesis-stress models

describe mental disorders that develop when someone with a pre-existing vulnerability for the disorder experiences a major stressor

diathesis

vulnerability; a predisposition toward developing a disorder that can derive from biological, psychological, or sociocultural causal factors

protective factors in diathesis-stress models

• decrease the likelihood of negative outcomes among those at risk

• warm, supportive family environment

• exposure to stressful experiences dealt with successfully, increase confidence and self-esteem

resilience in diathesis-stress models

• ability to successfully adapt to very difficult circumstances

• some individuals have a relatively good outcome despite suffering risk experiences that would be expected to bring about serious sequelae

sympathetic nervous system

• often referred to as the fight or flight system

• it prepared the body for stressful or emergency situations

• it increases heart rate, dilates airways, raises blood pressure, and inhibits digestion

parasympathetic nervous system

• known as the rest and digest system

• it conserves energy by slowing down the heart rate, reducing blood pressure, stimulating digestion, and promoting relaxation and recovery

transmission of information from one neuron to another

synthesis → transport → release → action on post-synaptic receptor → separation → reuptake

forebrain

responsible for complex cognitive activities, sensory processing, emotional regulation and voluntary motor activities

midbrain

plays a crucial role in vision, hearing, motor control, sleep/wake cycles, and temperature regulation

hindbrain

oversees fundamental life-supporting functions such as respiration, heart rate, and balance

the limbic system

• amygdala

• hippocampus

• hypothalamus

• thalamus

• cingulate gyrus

amygdala

involved in emotion processing, particularly fear and pleasure, and plays a role in emotional memory

hippocampus

essential for forming new memories and is involved in spatial navigation and contextual processing

hypothalamus

regulates autonomic functions and emotional responses, and plays a role in homeostasis, controlling hunger, thirst, and circadian rhythms

thalamus

acts as a relay station for sensory information, directing it to appropriate brain regions for further processing

cingulate gyrus

• involved in processing emotions and behaviour regulation, and helps regulate autonomic motor function

• the limbic system is integral to the brain’s ability to link emotions to sensory experiences

basal ganglia

• primarily involved in coordinating and controlling voluntary movements, as well as regulating muscle tone and motor learning

• help initiate smooth, purposeful movements and inhibit unwanted movements

• they also play a role in motor learning, habits, and certain cognitive and emotional functions

dysfunction of the basal ganglia

associated with movement disorders like Parkinson’s and Huntington’s

frontal lobe

responsible for voluntary movement, decision-making, problem-solving, and personality traits

parietal lobe

• processes sensory information such as touch, temperature, pain, and spatial awareness

• involved in understanding spatial relationships and coordinating movements

temporal lobe

processing auditory information and is crucial for hearing, language comprehension, and memory

occipital lobe

responsible for visual processing interpreting visual stimuli

dorsal raphe nucleu (DRN) pathway

• serotonergic pathway

• projects widely to the cerebral cortex, hippocampus, and basal ganglia

• plays key role in mood regulation, cognition, and arousal

median raphe nucleus (MRN) pathway

• serotonergic pathway

• projects mainly to hippocampus and other limbic areas

• involved in mood, anxiety, and memory

MRN and DRN projections to the thalamus and hypothalamus

influencing sleep, hunger, and autonomic functions

serotonergic pathway to the cerebellum

modulates motor control and coordination

serotonergic projections to the spinal cord

regulate pain perception and autonomic functions

locus coeruleus to the cortex

projects widely to the entire cerebral cortex, modulating attention, arousal, and cognitive functions

locus coeruleus to the limbic system

send fibres to the amygdala, hippocampus, and hypothalamus, influencing emotion, stress response, and memory

locus coeruleus to the thalamus

modulates sensory signal processing, arousal, and vigilance

locus coeruleus to the cerebellum

affects motor coordination

locus coeruleus to the spinal cord

involved in modulating pain and autonomic functions

mesolimbocortical pathway

• dopamine pathway

• originates from the ventral segmental area and projects to the nucleus accumbent, limbic areas, and prefrontal cortex

• involved in reward, motivation, and addiction

mesostriatal system

• dopamine pathway

• projects from the substantial nigra to the dorsal striatum

• involved in movement control and is affected in Parkinson’s

tuberoinfundibulnar pathway

• dopamine pathway

• projects from the hypothalamus to the pituitary gland, regulating prolactin secretion

emotional dysfunction and psychopathology

contributes to various psychiatric conditions: depression, anxiety, bipolar, PTSD, OCD, borderline, antisocial

emotion and behaviour

• basic patterns of emotional behaviour (freeze, escape, approach, attack) differ in fundamental ways

• emotional behaviour is a means of comunication

cognitive aspects of emotion

appraisals, attributions, and other ways of processing the world around you are fundamental to emotional experience

physiology of emotion

• emotion is a brain function involving the more primitive brain areas

• direct connection between these areas and the eyes may allow emotional processing to bypass the influence of higher cognitive processes

bidirectional influences

environment (physical, social, cultural), behaviour, neural activity, genetic activity influence individual development

risk factors

anything that increases the likelihood of developing a health or mental health condition, experiencing an injury, or facing a negative outcome

e.g., lifestyle choice such as tobacco use, unhealthy diet, physical inactivity, and excessive alcohol consumption

proximal risk factors

• occur shortly before occurrence of symptoms

• a crushing disappointment at school or work or severe difficulties with a school friend or a marital partner

distal risk factors

• occur early in life but don’t show effects for many years

• loss of a parent early in life may serve as a distal contributory cause predisposing a person to depression later in life

necessary causes

a characteristic (X) that must exist for a disorder (Y) to occur

e.g., Huntington’s Chorea (Y) can only develop if the person has the Huntington’s gene (X)

sufficient cause

condition that guarantees the occurrence of a disorder; if X occurs, then Y will also occur

contributory cause

increases the probability of a disorder developing but is neither necessary nor sufficient for the disorder to occur; if X occurs, then the probability of Y occurring increases

reinforcing contributory cause

condition/factor that tends to maintain maladaptive behaviour that is already occurring

e.g., the extra attention and sympathy that may come when a person is ill may unintentionally discourage recovery

biopsychosocial models

the dominant conceptual frameworks guiding research and practice on mental health conditions

causation to treatment

• knowledge about the causes of different mental health problems

• can provide direction for the development of effective interventions

the goal of primary prevention

to prevent mental health problems from developing in the first place

strategies of primary prevention

involves promoting overall well-being, reducing risk factors, and building protective factors

examples:

• mental health education programs in schools

• stress management workshops

• parenting skills training

• community awareness campaigns about mental health

• social support networks

goal of tertiary prevention

to manage existing mental healthcare conditions and reduce their impact on daily life

strategies of tertiary prevention

involves providing treatment and rehabilitation services

examples:

• psychotherapy

• medication management

• rehabilitation programs

• support groups

• case management and supportive housing