What is Depression?

Unipolar vs Bipolar Depression

Unipolar depression is characterised as someone experiencing frequent episodes of depressed mood, whereas an individual with Bipolar depression will swing between episodes of depression mood and ‘mania’. Mania is defined as periods of excitement, euphoria and overactivity. The image below highlights the main differences between unipolar and bipolar depression.

Bipolar
(Image source)

Depression is twice as common in women than in men, however men are more likely to commit suicide. Another type of depression is postpartum depression, otherwise known as postnatal depression, which occurs almost exclusively in women.

DSM-5 Criteria for Major Depressive Disorder

Below is the clinical criteria for MDD, as seen in the DSM (used in America). There are four main types of symptom:

  1. Emotional
  2. Physical
  3. Motivational
  4. Cognitive

• Depressed mood or a loss of interest or pleasure in daily activities for more than two weeks.
• Mood represents a change from the person’s baseline.
• Impaired function: social, occupational, educational.
• Specific symptoms, at least 5 of these 9, present nearly every day:

A1. Markedly diminished interest or pleasure in all or almost all activities most of the day nearly every day.
2. Significant weight loss when not dieting or weight gain.
3. Inability to sleep or oversleeping nearly every day.
4. Psychomotor agitation or retardation nearly every day.
5. Fatigue or loss of energy nearly every day.
6. Feelings of worthlessness or excessive or inappropriate guilt (which may be delusional) nearly every day.
7. Diminished ability to think or concentrate, or indecisiveness, nearly every day.
8. Recurrent thoughts of death, suicide, or a suicide attempt or has suicide plan

B. Symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning

C. The episode is not due to the effects of a substance or to a medical condition

D. The occurrence is not better explained by schizoaffective disorder, schizophrenia, schizophreniform disorder, delusional disorder, or other specified and unspecified schizophrenia spectrum and other psychotic disorders

E. There has never been a manic episode or a hypomanic episode


Brain2

Extension Resources

Here are some great TED Talks to give you a better idea of what it is like to experience clinical depression.