Depression Flashcards
What are the core symptoms of depression?
At least two weeks of low mood, lack of energy, lack of enjoyment/interest.
Also: depressive thoughts, biological/somatic symptoms
Which brain functions are involved in depressive symptoms?
The limbic system (hippocampus, amygdala, hypothalamus, cingulate gyrus, anterior nucleus of the thalamus)
Frontal lobe
Basal ganglia
What are the main functions of the limbic system?
Emotion, motivation, memory
What are the functions of the frontal lobe?
Motor function Language (Broca's) Executive function (goal directed) Attention Memory Mood Social and moral reasoning
What are the functions of the basal ganglia?
Motor function
Emotion
Cognition
Behaviour
What are the functional circuits involved with these areas?
The frontal lobe projects to parts of the limbic system, which itself connects to the basal ganglia and brainstem.
(This affects cognitive processing, sympathetic output, parasympathetic output, motor systems)
What are the main two neurotransmitters for depressive disorders?
Noradrenaline
Serotonin
(Also include dopamine, ACh, GABA, glutamate)
What are the functions of noradrenaline?
Mood
Behaviour (arousal and attention)
Memory functions
Where is noradrenaline produced?
Locus coeruleus (brainstem) Transported to several areas of cortex
What are the receptors for noradrenaline?
Alpha 1 and 2, beta 1 and 2
Beta functions in brain not clear, alpha is mood and arousal
What is the role of serotonin in the brain
Sleep
Impulse control
Appetite
Mood
Where is serotonin produced?
The brain stem (raphe nuclei) - transported to cortical areas and limbic system
What are serotonin associated causes/factors for depression?
5HIAA depletion in CSF (metabolite of serotonin) in depression patients
Tryptophan depletion (serotonin precursor) causes depression
SSRIs etc. work as antidepressants
What are predisposing factors for depression?
Genetics, childhood experiences, female gender
Stressful job/life situation
Life events eg losses/health difficulties
