An acronym for two mental disorders:
1)
Social Anxiety Disorder
Also known as
social phobia. It is a fear or worry about social situations. People with SAD often appear as being shy, but in extreme circumstances sufferers can become extreamly depressed and suicidal. Social anxiety causes difficulty with social interaction. It is a mental illness and should not be seen as just shyness.
2)
Seasonal Affective Disorder
A mental disorder which causes the sufferer to become extreamly depressed during the colder, darker winter months. Although it's not known what causes this, it is still a mental disorder and should be treated as such.