mood disorders

• Uncommonly, depression can be a reaction to a virus, or possibly to hormonal changes
• People with major depression find that almost nothing makes them happy
• Effective therapies for bipolar disorder

  • Lithium salts and certain other drugs
  • Consistent sleep schedule
• Antidepressants

  Alter synaptic activity quickly, but their effects on behavior require at least 2 weeks
• Most people with depression have a deficiency of the neurotrophin BDNF, which promotes development of new neurons, synapses, and learning in the hippocampus
• Psychotherapy is more likely than antipsychotic drugs to produce long-lasting benefits that prevent or delay a relapse after the end of treatment
• Antidepressant drugs are ineffective for many people
• Types of antidepressant drugs

  • Tricyclics block reuptake of serotonin and catecholamines
  • SSRIs block reuptake of serotonin
  • SNRIs block reuptake of both serotonin and norepinephrine
  • MAOIs block an enzyme that breaks down catecholamines and serotonin
  • Atypical antidepressants are a miscellaneous group with diverse effects
• Depression has a genetic predisposition, but no one gene has a strong effect by itself
• Most antidepressant drugs produce a gradual increase in BDNF, enhancing synaptic plasticity in the hippocampus
• Although different drugs affect different neurotransmitters, they all appear to be about equally effective
• In most cases, depression occurs as a series of episodes
• Depression is associated with decreased activity in the left hemisphere of the cortex
• Other therapies for depression

  • Electroconvulsive therapy
  • Altered sleep patterns
  • Exercise
• People with bipolar disorder alternate between depression and mania
• It is possible that the well-known effects of antidepressants on neurotransmitters are not the main reason for their effects on behavior
• The effects on BDNF may be the main reason for the drugs’ benefits
• For depressed patients with mild to moderate depression, antidepressants are not significantly more effective than placebos
• Psychotherapy is about as effective as antidepressant drugs for patients with all levels of severity
• Seasonal affective disorder is marked by recurrent depression during one season of the year
• Exposure to bright lights is usually effective in treating seasonal affective disorder
• Bipolar II disorder


  • Characterized by recurrent episodes of major depression and hypomania, a less severe form of mania compared to bipolar I disorder
• Atypical antidepressants


  • Target different neurotransmitters in the brain, such as dopamine, norepinephrine, and serotonin, to alleviate symptoms of depression
• Seasonal affective disorder (SAD)


  • Type of depression occurring in a seasonal pattern, typically during winter months with symptoms like low mood, fatigue, and increased appetite
• Bipolar disorder


  • Characterized by extreme mood swings including episodes of mania and depression
• Electroconvulsive therapy (ECT)


  • Medical treatment for certain mental illnesses involving the administration of electric currents to the brain to induce a controlled seizure
• Mania


  • State of abnormally elevated mood, energy, and activity levels, characteristic of bipolar disorder
• Tricyclics


  • Class of antidepressant medications that increase levels of neurotransmitters like serotonin and norepinephrine in the brain
• Postpartum depression


  • Type of depression occurring after childbirth, characterized by feelings of sadness, anxiety, and exhaustion
• Monoamine oxidase inhibitors (MAOIs)


  • Class of antidepressant medications that inhibit the enzyme monoamine oxidase involved in the breakdown of neurotransmitters like serotonin, norepinephrine, and dopamine
• Unipolar depression


  • Mood disorder characterized by persistent feelings of sadness, hopelessness, and loss of interest or pleasure in activities, without episodes of mania
• Serotonin norepinephrine reuptake inhibitors (SNRIs)


  • Class of antidepressant medications that increase levels of both serotonin and norepinephrine in the brain
• Bipolar I disorder


  • Characterized by manic episodes that may or may not be followed by depressive episodes
• Selective serotonin reuptake inhibitors (SSRIs)


  • Class of antidepressant medications that increase levels of serotonin in the brain
• Lithium


  • Commonly used medication to treat bipolar disorder by stabilizing mood and reducing the severity and frequency of manic and depressive episodes