• depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad or empty) or observation made by others (e.g., appears tearful). (In children and adolescents, this may be characterized as an irritable mood.)

• markedly diminished interest or pleasure in normal activities most of the day, nearly every day
• significant weight loss or weight gain (e.g., a change of more than 5% of body weight in a month), or decrease or increase in      appetite nearly every day.
• insomnia or hypersomnia (excessive sleeping) nearly every day
• psychomotor agitation (fidgeting like behaviour) or retardation (no real movement) nearly every day
• fatigue or loss of energy nearly every day
• feelings of worthlessness or excessive or inappropriate guilt nearly every day
• diminished ability to think or concentrate, or indecisiveness, nearly every day
• recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan, or a suicide attempt or a   specific plan for committing suicide
• finding it hard to take minor personal criticisms
• spending less time with friends and family
• Increased use of alcohol or other drugs
• Increased physical health complaints such as fatigue or pain

Some people who feel that they may be suffering from depression but do not quite fit into the above criteria may be suffering from Dysthmia.