Biological Theories of depression

• Biological explanations

  • Look at physical influences such as neurotransmitters, brain structures and genes
• Psychological explanations

  • Look at environment influences such as our family, thinking and past experiences
• Serotonin

  • Neurotransmitter responsible for sleep, improving mood and helping us pay attention
  • If we don't have enough, our mood lowers, our sleep gets worse and we can't pay attention
• Serotonin levels in depressed people

  • Low serotonin levels as there is not enough entering the post-synaptic neuron from the pre-synaptic neuron
  • Could be due to genes or diet
• Evaluation of Biological theories (1)

  • Strength
  • Research has found low levels of serotonin in the brains of depressed people
  • Research provides support
• Evaluation of Biological theories (2)

  • Weakness
  • We can't establish a cause and effect
  • We don't know whether low serotonin causes depression or depression cause low serotonin
• Evaluation of Biological theories (3)

  • Weakness
  • Ignores other causes of depression
  • Ignores how past experiences could affect depression
  • Doesn't explain all causes