Insomnia: can it be treated?

Hippocrates, the father of Medicine, spoke of the importance of sleep through this wonderful aphorism. However, it can be said that it was only in 1929 that the modern era of sleep investigation began, with the description of the electrical activity of the human brain by the German psychiatrist Hans Berger, who created the term “electroencephalography”. In Chicago in the 1930s, Loomis, Harvey and Hobart1 conducted the first systematic studies of electroencephalographic patterns during human sleep. They reported that sleep was not a continuous process but was characterized by distinct activity patterns that alternated throughout the night in an almost predictable manner. In 1953, rapid eye movement (REM) sleep was described formally by Aserinsky and Kleitman2. In 1957, Dement and Kleitman defined the existence of three totally distinct states of consciousness: wakefulness, non-REM sleep and REM sleep3; and in 1959, Jouvet and Michel discovered that in cats, REM sleep was characterized by atony of the axial musculature4. These findings, together with technological development, were fundamental to the pro­ gress of investigations on sleep and its disorders. In 1997, the first classification of sleep disorders was published5 and currently the 2005 version is used6. This is now undergoing revision for publication in 2014. Sleep disorders can be seen to have relevance to all fields of healthcare. Not only are these disorders highly prevalent, but also there is increasing knowledge of the repercussions of a bad night of sleep. For example, obstructive sleep apnea syndrome is currently one of the biggest public health problems, with well­defined cardiovascular risks. Insomnia is a very frequent complaint in medical consultation offices of any specialty. A study on a Brazilian population7 revealed that 35% of the individuals interviewed presented complaints of insomnia at least three times a week. However, despite all advances in knowledge, insomnia is still a challenge because of the generally complex nature of diagnostic and therapeutic approaches towards this condition. Its symptoms may result from various causes, such as use of medications, medical diseases, psychiatric disorders, poor sleep hygiene or primary sleep disorders, among others. Moreover, insomnia is a risk factor for mental and clinical disorders, substance and alcohol abuse and accidents. Around 57% of insomniac patients develop some kind of psychiatric condition. Insomnia is a predictive factor for a first episode of depression and for recurrence of depression and anxiety8. Therefore, when faced with a patient with a complaint of insomnia, careful investigation to identify factors that might be altering the patient’s sleep is essential, so that the correct therapeutic measures are taken. In this issue of Arquivos de Neuro-Psiquiatria, van der Mollen et al9 present a wide-ranging review of primary insomnia, with emphasis on non-pharmacological treatment. The authors firstly show the definition of insomnia as a symptom, which is important for its diagnostic comprehension. They then go beyond this by emphasizing the current view of insomnia in psychological terms (cognitive components and behavioral factors) and in physio logical terms (high metabolic rate, with increased muscle tonus, heart rate and temperature). They also show the neurobiology of insomnia from two perspectives: one poin ting towards failure of inhibition of wakefulness and the other considering hyper-alertness to have an important role. Comprehension of these characteristics has a fundamental role in approaches Clinical Neurophysiologist, Setor de Polissonografia, Instituto de Psiquitaria, Hospital das Clínicas, Faculdade de Medicina de São Paulo and Hospital Israelita Albert Einstein, São Paulo, SP, Brazil.