Caffeine-induced sleep disorder is a psychiatric disorder that results from overconsumption of the stimulant caffeine

Caffeine

Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...

. "When caffeine is consumed immediately before bedtime or continuously throughout the day, sleep onset may be delayed, total sleep time reduced, normal stages of sleep altered, and the quality of sleep decreased."

The specific criteria for this disorder in the fourth version of the Diagnostic and Statistical Manual of Mental Disorders

Diagnostic and Statistical Manual of Mental Disorders

The Diagnostic and Statistical Manual of Mental Disorders is published by the American Psychiatric Association and provides a common language and standard criteria for the classification of mental disorders...

(DSM-IV) include that there must be a significant inability to sleep which is caused entirely by the physiological effects of caffeine as proven by an examination; if sleeping issues can be accounted for due to a breathing-related sleep disorder, narcolepsy

Narcolepsy

Narcolepsy is a chronic sleep disorder, or dyssomnia, characterized by excessive sleepiness and sleep attacks at inappropriate times, such as while at work. People with narcolepsy often experience disturbed nocturnal sleep and an abnormal daytime sleep pattern, which often is confused with insomnia...

, or another mental disorder, then caffeine-induced sleep disorder is not the cause. This condition causes a notable impairment in functioning in sufferers.