12 - Pshchiatry intro 4 lectures Flashcards
organic vs functional in psychiatry
Functional – neurotic disorders (e.g. depression, anxiety, phobias) or psychotic disorders (e.g. schizophrenia, bipolar disorder) we may all experience for a while
Organic- e.g. dementia, psychiatric
manifestations of epilepsy or Parkinson’s or
stroke, acquired or traumatic brain injury,
Huntington’s disease, drug-induced states,
etc.
define anxiety, what are its symptoms
a feeling of worry about an uncertain outcome
- Palpitations
- Sweating
- Trembling or shaking
- Dry mouth
- Difficulty breathing
- Chest pain or discomfort
- Nausea or abdominal distress (e.g. butterflies in stomach)
- Feeling dizzy, unsteady, faint or light-headed
anxiety is a normal response of the limbic system stimulating the sympathetic NS in response to a threat
outline how the limbic system responds to stressors
o This response is mediated primarily by the limbic system, which has neural and endocrine targets
Neural elements of the stress response (limbic system)
• Hippocampus
o Receives inputs from many parts of the cortex and
processes their emotional content
o Ultimately projects to the thalamus and also to the
hypothalamus
(causing autonomic features of
emotional responses, since the hypothalamus send
projections down through the cord to autonomic
preganglionic neurones – the hypothalamospinal tract.
This will lead to sympathetic nervous system activation,
as well as release of adrenaline from the adrenal
medulla – the acute stress response)
• Amygdala
o Almond shaped structure sitting near the tip of the
hippocampus
o Receives many inputs from the sensory system
o Major outputs to cortex and hypothalamus
Endocrine elements of the stress response
• The limbic system is able to act on the hypothalamus to
stimulate the secretion of stress hormones
o Via the familiar hypothalamo-pituitary-adrenal axis
o Release of cortisol from the adrenal cortex is part of
the ‘chronic’ stress response
key facts on the hippocampus
Folded into medial surface
of temporal lobe
Occupies floor of temporal
horn of lateral ventricle
Three parts: subiculum,
hippocampus proper,
dentate gyrus
Involved in memory and
expressions of emotion
key facts on the amygdala
Buried in the roof of lateral ventricle
Collection of nuclei
Inputs of sensory information, brainstem, thalamus, cortex
Outputs to cortex, brainstem and hypothalamus
Drive related behaviours and processing of associated emotions
anxiety pathologically is when we gain a stress response to a threat that cannot be ran away from ie work ect
bonus
what are the key anxiety disorders ?
PTSD
OCD
Panic and socail disorders
generalised anxiety
briefly outline the 3 stages of the general adaptation syndrome to stress
The general adaptation syndrome refers to three stages that the body goes through
during prolonged exposure to stressors
o Stage 1: The alarm reaction
Release of adrenaline and cortisol as well as sympathetic activation
(described above)
o Stage 2: Resistance (effect of adrenaline starts to wear off)
Chronic stress response, prolonged release of cortisol
o Stage 3: Exhaustion (when you cannot escape an ongoing stressor)
Chronic side effects of prolonged cortisol secretion start to occur
o The stress response can become pathological when you cannot escape a
stressor(s), or when ‘trivial’ stressors elicit a strong stress response.
However, patients with anxiety disorders may go through all of the stages
above
what is GABA and its role in stress
it is the main inhibitory neurotransmitter
it is lower in patients with panic disorders
we can treat with benzodiazepines(short term only) to increase gaba transmission decreasing anxiety
long term we also can increase seretonin with ssri’s
and give patient CBT
outline OCD
obsessions - they dominate the thoughts and are unpleasant
compulsions - are motor acts to neutralise the obsessive impulse
the patient acknowledges the obsession is unreasonable or excessive but cannot stop it
repetitive and unpleasant
side fact - PANDAS - a strep infection in a child can trigger OCD symptoms due to antibody cross reaction with neurons of basal ganglia - kinda mad
treatment of OCD is …
o Treatment Biological • SSRIs +/- antipsychotics - help block basal ganglia re entry loops ? • Deep brain stimulation? Psychological • CBT and variety of other interventions Social • Family support • Groups etc
outline PTSD
o Features
Can occur within six months following an exceptionally severe traumatic event (e.g. rape, battlefield trauma)
Causes repetitive, intrusive recollection or re-enactment of the event in memories, daytime imagery, or dreams
There is conspicuous emotional detachment, numbing of feeling, and avoidance of stimuli that might arouse recollection of the trauma
o Pathophysiology
Unclear
• Evidence of amygdala hyperactivity causing exaggerated behavioural responses
• However, low levels of cortisol!
PTSD treatment
Treatment Biological • SSRIs • Maybe short term benzodiazepines Psychological • CBT • Eye movement desensitization reprocessing therapy Social • Charities are particularly active, such as ‘Help for Heroes’
what are the features of Depression
more than two weeks
core of low mood, low energy, lack of enjoment in anything
depressive throughts
may stop eating
some somatic biological symptoms
most severe - psychotic symptoms possible
depression vs adjustment reaction
in a ADR - energy is not low time is limited onset sudden after event not gradual no sleep disturbance pattern anger is common unlike depression
