text: what is the difference between a nervous breakdown and a panic attack? and is there anyway a person (me) observing either behavior would be able to distinguish the two states? nervous breakdown: what is it? what is a nervous breakdown? what causes people to have them? - linda / minnesota mayo clinic psychiatrist daniel hall-flavin, m.d., and colleagues answer select questions from readers. answer  nervous breakdown is a term that the public uses to characterize a range of mental illnesses. it's not a medical term, and it doesn't indicate a specific mental illness. generally, it describes a person who is severely and persistently emotionally distraught and unable to function at his or her normal level.  often, when people refer to having a nervous breakdown, they're describing severe depression. signs and symptoms of severe depression include:      * agitation or restlessness     * difficulty or inability to stop crying     * sleeping difficulties     * indecision  the causes of mental illness usually aren't clear. but these factors may play a role:      * stress     * drug and alcohol use     * co-existing medical conditions, such as thyroid disorders and certain vitamin deficiencies     * genetics http://www.mayoclinic.com/health/nervous-breakdown/an00476