Misdiagnosing sleep disorders

There is a compelling argument for viewing sleep and its disorders as a central theme in psychiatry and for clinicians to be familiar with sleep disorder medicine whatever the age of their patients. Sad to say, however, psychiatry (and, for that matter, clinical psychology) generally shares in the neglect of this field in medical and other teaching and training areas. There are several main points of contact between psychiatry and sleep disorders. The first is that sleep disturbance is a common feature of a wide range of psychiatric disorders in adults (Benca, 2000) and also in children and adolescents (Stores & Wiggs, 2001). This is well recognised in depression, where clinical abnormalities of sleep are prominent and where disturbed sleep physiology is also a feature (at least, in severe depressive disorders in adults), possibly with aetiological, therapeutic and prognostic implications. Brunello et al (2000) have reviewed these issues, pointing out the various unknowns that need further research. The various types of sleep disorder which commonly complicate the whole range of psychiatric conditions seem to be less well known. Not only are psychiatric disorders themselves capable of affecting sleep and wakefulness: certain psychotropic medications can have the same effect (Obermeyer & Benca, 1996), possibly adding to the patient’s difficulties. Sleep disturbance can be an early sign of impending psychiatric disorder. A review by Gillin (1998) demonstrates that, in both those with and without a serious psychiatric history, insomnia and/or hypersomnia are risk factors for later development or recurrence of depression, anxiety states or substance misuse. Detection and treatment of the sleep disturbance at an early age might have important preventive value (Ford & Kamerow, 1989). The significance of sleep disturbance in various forms, not merely insomnia, in psychiatric disorders is illustrated by the recent report of a close association between nightmares and death from suicide in the general population (Tanskanen et al, 2001). Another important connection between sleep disorders and psychiatry concerns the harmful effects on psychological function of sleep disturbance, especially if it is persistent. This disturbance may take the form of loss of sleep, impaired quality of sleep and/or inappropriate timing of the sleep period. Experimental findings and clinical observation have demonstrated potentially widespread effects on mood, behaviour and performance in adults with no previous psychological problems (Bonnet, 2000). There are increasing reports of comparable effects in children and adolescents (Fallone et al, 2002). These adverse influences on psychological function are considered by many to be particularly serious because sleep disturbance is seemingly so common in modern Westernised societies. Reports of disturbed psychological function attributable to sleep disturbance are in keeping with the idea that the sleep disturbance may be a contributory factor (and in some cases the basic cause) of actual psychiatric illness. For example, it has been suggested that sleep disturbance has at