Sleep Disorders

Introduction

Sleep disorders  disturb the normal sleep pattern and may cause fatigue, irritability, anxiety, and impaired memory and concentration. Some sleep disorders are also associated with increased morbidity and mortality.

According to the DSM-IV and ICD-10 classification systems, the primary sleep disorders can be divided into two main groups: dyssomnias and parasomnias. Dyssomnias are disorders in which the length, timing or type of sleep are different from normal. They include insomnias, hypersomnias and circadian rhythm  sleep disorders. Parasomnias are disorders in which an undesirable phenomena occurs, for example sleepwalking, sleep terrors, bruxism and enuresis.

Some sleep disorders are found in conjunction with psychiatric disorders, eg depression, neurological disorders, eg Parkinson's disease  and other medical disorders e.g. endocrine problems.