Diagnosis
Specialists in sleep medicine are qualified to diagnose the many different sleep disorders. Patients with various disorders, including delayed sleep phase syndrome, are often mis-diagnosed with primary insomnia. When a person has trouble getting to sleep, but has a normal sleep pattern once asleep, a circadian rhythm disorder is a likely cause.
In many cases, insomnia is co-morbid with another disease, side-effects from medications, or a psychological problem. Approximately half of all diagnosed insomnia is related to psychiatric disorders. In depression in many cases "insomnia should be regarded as a co-morbid condition, rather than as a secondary one;" insomnia typically predates psychiatric symptoms. "In fact, it is possible that insomnia represents a significant risk for the development of a subsequent psychiatric disorder."
Knowledge of causation is not necessary for a diagnosis.
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