Depression

Question 1

Describe the symptoms of depression

Answer 1

• Patients have the symptoms continually for 2 weeks
• Core symptoms:
  
  • Low mood
  • Lack of energy
  • Lack of enjoyment & interest
• Depressive thoughts
• Weight loss
• Trouble sleeping / consistently waking up early

Question 2

State causes of depression

Answer 2

• Physical disorders
• Alcohol/drugs
• Predisposing (genetics)
• Perpetuating (social stressors)
• Precipitating factors (life events of death, loss)

Question 3

State some physical causes of depression

Answer 3

• Hormone disturbance such as thyroid dysfunction - hypothyroidism
• Vitamin deficiencies such as vitamin B12
• Heart and lung disease
• Blood vessels not functioning well - TIA/stroke leading to cerebral disease (damage to brain)
• Kidney disease
• Liver disease

Question 4

State some predisposing causes of depression

Answer 4

• Genetics
• Childhood experiences - quality of attachment, quality of parental relationships, loss of a parent, bullying
• Female gender - child care stress

Question 5

Describe some perpetuating causes of depression

Answer 5

• Stressful job, studies, financial strain, housing, unemployment
• Relationship difficulties
• Substance misuse

Question 6

Describe some precipitating causes of depression

Answer 6

Live events often related to losses such as death, loss of health, and loss of relationships

Question 7

Describe the brain structures involved in depression

Answer 7

• Limbic system involved in emotion, motivation and memory
  
  • Lack of motivation can lead to stop eating/drinking, bed bound and psychosocial retardedness (slowed response, cognitive functions, concentration)
    Frontal Lobe
• Frontal lobe involved in motor function, language, attention (concentration), memory, mood, social and moral reasoning
  
  • Depression mainly affects the pre-frontal area
    
    • Linked to person’s will to live and personality
      Basal Ganglia
• Basal ganglia: motor function - stimulation/inhibition of motor cortex
  
  • Psychological function - emotion, cognition, behaviour
    Circuits
• The main hypothesis is that mood is determined by functional circuits between basal ganglia, frontal lobe and limbic system
  
  • Frontal lobe projects to parts of the limbic system which in turn connects to the basal ganglia and brainstem
    • Affects cognitive processes (thoughts), sympathetic/parasympathetic output and motor systems

Question 8

What are the main neurotransmitters for depressive disorders

Answer 8

• Noradrenaline

- Serotonin

Question 9

Describe the role of noradrenaline in depression

Answer 9

• Noradrenaline involved in mood, behaviour (arousal and attention) and memory functions
• AMPT inhibits tyrosine to L-DOPA, which is a precursor to dopamine and then noradrenaline
  
  • Decreases noradrenaline production and concentration in synaptic cleft
    
    • Leads to sleepiness, increased anger, calmness, depressive symptoms

Question 10

Describe the anti-depressants linked with noradrenaline

Answer 10

• Anti-depressants
  
  • Noradrenaline reuptake inhibitor (NARI) - does not work effectively
  • Tricyclic anti-depressants (TCA) - blocks serotonin and noradrenaline transporters, resulting in elevated concentrations in synaptic cleft
  • Selective noradrenaline + serotonin reuptake inhibitor (SNRI)
• Drugs including Reserpine (antipsychotic and antihypertensive drug) affect noradrenaline
  - Reserpine depletes the nerve ends of noradrenaline

Question 11

Describe the role of serotonin in depression

Answer 11

• Serotonin involved in sleep, impulse control, appetite, and mood
• Produced in the brain stem and transported to cortical areas and limbic system
• In depression patients, 5HIAA depletion in CSF (a metabolite of serotonin)
  
  • Tryptophan depletion (precursor for serotonin) causes depression
  • Reserpine - depletes nerve endings from mono-amines
• Anti-depressants - SSRI, TCA, SNRI, MAOI (monoamine oxidase inhibitor)

Question 12

Describe the medication given to depressive patients

Answer 12

• Selective serotonin reuptake inhibitors
  
  • Safe and well tolerated
  • Used for patients with moderate/severe depression
• Combination therapy used if patients resistant to SSRI and other drugs
• Mood stabilisers - lithium

Question 13

Describe the use of non-pharmacological interventions against depression

Answer 13

• Cognitive based therapy (CBT)
• Try and get patient back to work
• Encourage patient to resume previous activities they used to enjoy