BIOMED SCIE L ecture 22 dedpression

• Neurotransmitters


  • Acetylcholine
  • Amino acids and derivatives (including glutamate, GABA, glycine, histamine, serotonin)
  • Monoamines (serotonin, norepinephrine, dopamine)
  • Nucleotides (adenosine, ATP)
  • Peptides (endorphins, oxytocin, substance P)
• Acetylcholine


  A classical neurotransmitter involved in muscle contraction
• Glutamate


  Major excitatory neurotransmitter
• GABA


  Major inhibitory neurotransmitter
• The lifetime risk of experiencing at least one episode of major depression is 17.1% (21% in women, 13% in men)
• Depression is the second leading cause of disability worldwide after ischemic heart disease
• Depression is a high risk factor for suicide (higher rate in men)
• Mood Disorders


  Includes various forms of major depression (unipolar) and bipolar disorder (alternating depression with manic episodes)
• Diagnosis of mood disorders is based on DSM-5 without objective tests available
• Causes of Depression


  • Genetic factors (hereditary predisposition involving multiple genes)
  • Environmental factors (chronic stress and hormonal response)
  • Symptom of many medical conditions
• Monoamine Hypothesis of Mood Disorders


  Involvement of neurotransmitters like serotonin, norepinephrine, and dopamine
• Antidepressant drugs


  Aim to enhance neurotransmitter function
• Treatment of Depression


  • Psychotherapy
  • Electroconvulsive therapy (ECT)
  • Antidepressant medications
• Limitations of antidepressant drugs include variable response times and efficacy
• Cytokine Hypothesis of Depression


  Similarities between sickness behavior and depression, immune abnormalities and chronic inflammation associated with depression
• Adult Neurogenesis and Depression


  Neurogenesis influenced positively by stimulating environments, exercise, learning, and antidepressant treatment, reduced by stress, age, and opiates
• Network Hypothesis of Depression


  Depression may result from information processing issues, antidepressant treatment may promote neural network "repair"