불면증 : 원인과진단 안동현 http://dx.doi.org/10.7599/hmr.2013.33.4.203 pissn 1738-429X eissn 2234-4446 한양대학교의과대학정신건강의학교실 Insomnia: Causes and Diagnosis Dong Hyun Ahn Department of Psychiatry, Hanyang University College of Medicine, Seoul, Korea Insomnia is the most common sleep problem affecting nearly one-third of the population as either a primary or comorbid condition. Insomnia has been defined as both a symptom and a disorder, and is characterized as sleep that is chronically unrestorative or poor in quality often due to difficulty in initiating sleep, in maintaining sleep, or with waking up too early. Insomnia results in some form of daytime impairment in the patient s normal activites. Although the exact pathophysiology of insomnia is poorly understood, it is often believed to arise from a state of hyperarousal in multiple neurophysiological and/or psychological systems. Population-based studies suggest that while about one-third of the general population complains of sleep disturbance, only 10-15 percent has associated symptoms of daytime functional impairment, and even fewer, only 6-10 percent have impairments sufficient for the diagnostic criteria of insomnia. The cornerstone of the insomnia evaluation and diagnosis is a comprehensive history obtained by the clinical interview with patient and/or family. Additional assessment tools, such as sleep diary or log, various questionnaires, actigraphy, and multichannel polysomnography (PSG) have been used as an aid to diagnosis, although many are limited in their validation. Insomnia causes a significant burden of medical, psychiatric, societal consequences on the individual and societal level. Clinicians in either primary settings or specialized clinics should have knowledge to manage insomnia with confidence. Correspondence to: Dong Hyun Ahn 우 133-792, 서울시성동구왕십리로 222, 한양대학교병원정신건강의학과 Department of Psychiatry, Hanyang University Hospital, 222 Wangsimni-ro, Seoungdong-gu, Seoul 133-792, Korea Tel: +82-2-2290-8425 Fax: +82-2-2298-2055 E-mail: ahndh@hanyang.ac.kr Received 2 September 2013 Revised 8 October 2013 Accepted 15 October 2013 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Key Words: Sleep Initiation and Maintenance Disorders; Prevalence; Diagnosis 서론불면은일반인들의약 1/3이호소할정도로매우흔한증상이다. 일차진료현장은물론정신과, 신경과, 내과, 외과등거의모든진료영역에서아주흔하게접하는호소이자증상이기도하다. 불면증은잠을잘수있는여건이나환경에도불구하고잠을자지못하거나잠을자더라도자주깨거나혹은너무일찍깨거나, 아니면숙면을취하지못하는수면이상을일컫고, 따라서매우다양한형태로나타날수있다. 최근수면다원검사등을이용한수면의학의발달로인해수면이상혹은수면장애와관련한그동안알려지지않았 던많은것들이밝혀지고있음에도불구하고, 불면증의원인, 진단은말할것도없고치료는여전히어렵다. 불면증의정의및최근새롭게제시된불면증의분류를포함하여역학, 자연경과, 원인, 진단및평가, 그리고불면과관련한사회적부담까지기존연구자료등을근거로개괄한다. 본론 1. 정의및분류불면증 (insomnia) 은수면을취할수있는적절한기회와환경에 http://www.e-hmr.org 2013 Hanyang University College of Medicine 203
Dong Hyun Ahn Insomnia: Causes and Diagnosis 도불구하고수면이상을호소하는것으로정의된다 [1]. 여기에서수면이상이란흔히 1) 잠이들기어렵다 (initiating sleep), 2) 수면을유지하기어렵다 (maintaining sleep), 3) 너무일찍깬다 (early wakening sleep) 는것을말하고, 추가로 4) 잠을잔것같지않은수면 (non-restorative or poor-quality sleep) 을포함하기도한다 [1,2]. 불면증은구체적인증상, 기간, 원인등에기반하여분류하는데, 몇가지공식적인불면증의분류가있다. 흔히세계보건기구 (World Health Organization, WHO) 국제질병분류 (ICD-10-CM) 의수면장애분류, 미국정신의학회 (American Psychiatric Association, APA) 의정신질환분류 (DSM-5) 가운데수면장애분류, 수면관련학회에서제안한국제수면장애분류 (ICSD-2, 2005) 가가장널리사용된다. 각분류체계에서불면증의분류가다소차이를보이는데먼저불면증을포함한전반적인수면장애 (sleep disorders) 를 ICSD-2에서는 1) 불면증, 2) 수면관련호흡장애, 3) 수면과다증 ( 중추형 ), 4) 일주기리듬수면장애, 5) 수면수반증 ( 혹은사건수면 ), 6) 수면중이상운동, 7) 단일증상들, 8) 기타수면장애의 8개카테고리로구분하고그가운데불면증은 Table 1과같이 10개하위유형으로구분한다. 이가운데일차성불면증은 Table 1에제시된상위 6개를말한다. 이에비해 ICD-10-CM 에서는일차성및정신질환과관련한불면증은 F51의정신장애카테고리로분류하고, 신체질환혹은약물과관련한기질성불면증을포함한일주기리듬수면장애, 수면무호흡증, 기면증등은 G47 신경계질환카테고리로분류하고있다 [3]. 최근미국정신의학회의정신질환분류-5차개정판 (DSM-5) 에서는이를수면-각성장애 (sleep-wake disorders) 아래불면증, 과수면증, 기면증, 호흡관련수면장애, 일주기리듬수면각성장애, 수면수반증, 약물에의한수면장애, 기타수면장애로구분하였다. 그리고불면증의세부하위유형을없애단순화하는대신 Table 1과같이정신질환, 신체질환, 기타수면장애를동반하는지여부와경과 ( 삽화성, 지속성, 재발성여부 ) 를구체적으로명시하도록하였다 [1]. 불면증의분류가세가지분류체계에따라약간의차이를보이듯이불면증의정의또한분류체계간차이를나타낸다. 이를요약해보면 Table 2와같다. ICD-10-CM 은매우포괄적으로정의하고있고, ICSD-2 에서는주간의이상 (daytime impairment) 을구체적으로명시하고있는반면 DSM-5 에서는불면증의회수, 기간등을구체적으로제시하고있다. 2. 발생빈도및역학불면증의발생빈도는정확하게알수가없다. 하지만여러연구들을종합해보면일반인구가운데약 1/3 정도가불면증상을호소하며, 10-15% 정도가낮에기능상지장 (impairments) 을경험하고, 불면증진단기준에합당한비율은 6-10% 로알려져있다. 불면증은모든수면장애가운데발생빈도가가장높고, 일차진료현장에서약 10-20% 정도가상당한정도의불면증상을호소하고 [1], 국내의 Table 1. The classification of insomnia of ICSD-2, ICD-10-CM, DSM-5 ICSD-2 (2005) 1. Adjustment sleep disorder (acute insomnia) 2. Psychophysiological insomnia 3. Paradoxical insomnia 4. Idiopathic insomnia 5. Inadequate sleep hygiene 6. Behavioral insomnia of childhood 7. Insomnia due to drug or substance 8. Insomnia due to medical condition 9. Insomnia not due to a substance or known physiological condition, unspecified 10. Physiological (organic) insomnia, unspecified ICD-10-CM (1994) F51 Sleep disorders not due to a substance or known physiological condition F51.01 Primary insomnia F51.02Adjustment insomnia F51.03 Paradoxical insomnia F51.04 Psychophysiological insomnia F51.05 Insomnia due to other mental disorder F51.09 Other insomnia not due to a substance or known physiological condition G47 Organic sleep disorders G47.0 Insomnia, unspecified G47.01 Insomnia due to medical condition G47.09 Other insomnia DSM-5 (2013) 1. Insomnia disorder Specify if: With non-sleep disorder mental comorbidity With other medical comorbidity With other sleep disorder Specify if: Episodic Persistent Recurrent 2.Other specified insomnia disorder Unspecified insomnia disorder ICSD, The International Classification of Sleep Disorders; ICD, International Classification of Diseases; DSM, Diagnostic and Statistical Manual. Ref. 1 with permission from American Psychiatric Publishing; Ref. 3 with permission from Springer. 경우더높은비율 (32.5%) 을보고하였다 [4]. 남녀비율을보면남성 에비해여성에서더흔하게발생하여남성대여성의비율은 1:1.44 이다 [1]. 국내의경우 5,000 명성인을대상으로한수면장애관련전화역 학조사연구에서불면증호소는 22.8% 이고, 남녀빈도를보면여성 25.3%, 남성 20.2% 로역시여성이높고, 연령에따라증가하며 60-69 세연령에서 34.6% 로가장높았다 [5]. 그들은 1 주에적어도 2 회이상 의불면증을갖는경우로범위를좁혔을때발생빈도는 14.9% 로보 고하였고, 역시여성 17.0%, 남성 12.8% 로여성에서발생이높았다. 불면증은증상이기도하고독립적인질병이기도하지만, 다른신 체질환혹은정신질환과동반해서도잘발생하는데, 예를들어불 면증을호소하는사람들의 40-50% 에서정신질환을공병으로갖 는다 [1]. Mai 등은여러문헌을검토하면서불면증이정신질환에 잘동반할뿐아니라, 주요우울장애, 공황장애, 알코올남용, 그뿐 204 http://www.e-hmr.org
안동현 불면증 : 원인과진단 Table 2. Comparison of the diagnostic criteria of insomnia of ICSD-2, ICD-10-CM, DSM-5 ICSD-2 1. A complaint of difficulty initiating sleep, difficulty maintaining sleep, or waking up too early or sleep that is chronically unrestorative or poor in quality. 2. The above sleep difficulty occurs despite adequate opportunity and circumstances for sleep 3. At least one of the following forms of daytime impairment related to the nighttime sleep difficulty is reported by the patient: Fatigue or malaise Attention, concentration or memory impairment Social or vocational dysfunction or poor school performance Mood disturbance or irritability Daytime sleepiness Motivation, energy, or initiative reduction Proness for errors or accidents at work or while driving Tension, headaches or gastrointestinal symptoms in response to sleep loss Concerns or worries about sleep ICD-10-CM 1. A condition of unsatisfactory quantity or quality of sleep, which persists for a considerable period of time, including difficulty falling asleep, difficulty staying asleep, or early final wakening. 2. Insomnia is a common symptoms of many mental and physical disorders, and should be classified here in addition to the basic disorder only if it dominates the clinical picture. DSM-5* A. A predominant complaint of dissatisfaction with sleep quantity or quality, associated with one (or more) of the following symptoms: 1. Difficulty initiating sleep 2. Difficulty maintaining sleep, characterized by frequent awakenings or problems returning to sleep after awakenings. 3. Early-morning awakening with inability to return to sleep B. The sleep disturbance causes clinically significant distress or impairment in social, occupational, educational, academic, behavioral, or other important areas of functioning C. The sleep difficulty occurs at least 3 nights per week. D. The sleep difficulty is present for at least 3 months. E. The sleep difficulty occurs despite adequate opportunity for sleep. F. The insomnia is not better explained by and does not occur G. The insomnia is not attributable to the physiological effects of substance. H. Coexisting mental disorders and medical conditions do not adequately explained the predominant complaint of insomnia *The diagnosis of insomnia disorder is given whether it occurs as an independent condition or id comorbid either another mental disorder or another sleep disorder. Ref. 1 with permission from American Psychiatric Publishing; Ref. 6 with permission from Elsevier. 아니라청소년자살의발병전에나타나는데, 불면증이이들질환의초기증상혹은잠복기의일부일수있다고도하였다 [6]. 그뿐아니라, 그들은불면증환자들에게서심장질환, 고혈압, 만성통증, 위장관, 신경계, 비뇨기및호흡기곤란등의비율이높아짐을제시하였다. 특히심혈관계질환과불면증의관계는연령및위험요소들을보정하였을때상대위험률이 1.5-3.9 였다. 이같이불면증은여러정신질환은물론많은신체질환과도밀접한연관이있으며, 위험률을높이기도하여진료현장에서불면증을적절하게진단, 평가하고치료하는것이관련한질환을치료하는데매우중요하다. 3. 자연경과및기간불면증은언제든지발생할수있어아동기혹은청소년기에증상이나타나는경우도있지만, 대개성인기초기에가장흔하게발생한다. 여성의경우, 폐경기에발생하여다른증상들 ( 예, hot flushes) 이사라진후에도지속하는수가있다. 노년기에발생하기도하지만, 흔히는다른질환이나건강상문제와연관되는수가많다. 불면증의분류에서이미언급하였지만, 불면증은삽화성, 지속 성, 재발성으로나타날수있다. 급성 (acute) 혹은상황적 (situational) 불면증은보통수일에서수주에걸쳐지속하는데종종생활사건 (life events) 혹은수면리듬이나환경의급격한변화와연관된다. 이런경우처음유발사건이해결되면호전되는수가많다. 종종수면장애에취약한사람의경우, 최초의촉발사건 (triggering events) 후에장기간지속하는수가있는데, 이는불면증의유발인자와그것을지속시키는요인이다를수있음을보여주는것이다. 예를들면통증을동반하는손상으로누워지내면서불면증을호소하던환자가수면에대해부정적연관을발전시키고결국이러한조건화된각성으로인해지속적인불면으로전이되는수가있다 [1]. 또다른예로우울증환자의우울삽화중에발생한불면증이관심의초점이되고결과적으로부정적조건화를초래하여우울증삽화가호전되니이후에도불면증은계속되는수가있다. 이같은만성화경과에대해몇가지장기추적연구를보면 Green 등은영국스코틀랜드에서 20년추적연구를수행하여 4가지수면유형, 건강형 (37%), 삽화형 (22%), 만성형 (17%), 점진발생형 (24%) 으로구분하였는데, 여성, 고령, 육체노동종사의경우만성화경향이높은것으로보고하였다 [7]. Morin 등은여성, 고령외에불면증상의심 http://www.e-hmr.org 205
Dong Hyun Ahn Insomnia: Causes and Diagnosis 한정도, Buysse 등은여성, LeBlanc 등은우울증상, 높은각성도를제시하고있다 [8-10]. Morin 등은 3년추적연구에서 46% 가불면증이지속됨을보고하였고, 호전된대상군가운데 27% 가재발을하는것으로보고하였다 [8]. 연령에따라불면증이다소다른양상을보이는데, 아동및청소년기에도잠이들기가어렵거나자주깨는수가있지만이에관한자세한발생빈도, 위험요소, 동반질환등에대해알려진바가매우제한적이다. 주목할것으로아동기에는조건화요인들 ( 예, 부모가없이혼자잠드는것을배우지못한경우등 ), 일정한수면스케줄및취침습관 (bedtime routines) 을갖지못한경우가많다. 청소년기에는종종불규칙한수면스케줄에의해촉발되거나악화되는수가있다 [1]. Zhang 등은아동불면증장기추적연구에서많은아동들이만성화경과를밟으며, 특히청소년기불면증과음주 / 흡연, 만성신체질환, 잦은분노발작, 불량한정신건강과의관련성이있음을실증적으로보여주었다 [11]. 노년기성인에서불면증호소가많은데, 성인기초기에초기불면증 ( 잠들기가어렵다 ) 이많은것에비해이들에게서는중기불면증 ( 수면중자주깨는것 ) 이더흔하다. 또한노년기에불면의발생이높아지는것은일부고령화에따른신체건강문제의높은발생과도연관된다, 그리고정상적인노화과정에서일어나는수면패턴의변화와도구분해야한다. 4. 원인, 병태생리및위험요인들불면증은주요생활사건 ( 예, 질병, 이별등 ) 혹은일상생활에서의심한스트레스와같은유발인자에의해노출될때발생할수있다. 대부분의사람들은최초의촉발사건이사라지면정상수면패턴으로돌아가지만, 수면장애에취약한일부사람들은지속적인불면증으로만성화되기도한다. 즉, 촉발혹은유발요인과지속요인이다를수있으며, 잘못된수면습관, 불규칙한수면스케줄, 수면에대한두려움과같은지속요인으로인해불면증이만성화되도록하는수가있다 [1]. 이와함께이미자연경과에서언급했지만, 여성, 고령, 육체노동종사, 그외에불면증상의심한정도, 우울증상, 높은각 성도등이불면증을만성화하는요인이다 [1,7-10]. 불면증의원인및병태생리에대해서는아직명확하게밝혀져있지않다. 유전적요인에대해서는일란성쌍생아연구에서일란성과이란성의상대위험률이각각 0.47, 0.15로유전적요인이있음을밝힌보고가있기만하지만매우제한적이다 [12]. 불면증의병태생리와관련하여과각성모형 (hyperarousal model) 이널리제안되었다 [13]. Riemann 등 (2011) 은 Spielman 등 (1987) 의소인 (predisposing) 및유발요소 (precipitating factors) 에의해불면증이시작해서지속요소 (perpetuating factors) 에의해만성화된다는제안을기본으로해서, 이를발전시킨 Perlis 등 (1997) 의신경인지모형 (neurocognitive model), Espie 등 (2006) 의인지-심리이론 (cognitive-psychological theory) 과같은과각성개념에수면-각성조절의신경생물학및신경화학적지식을결합시켜만성불면증의병태생리를설명하고있다. 그들은이를 flip-flop switch model이라고하여수면촉진영역 (ventrolateral preoptic nucleus, VLPO) 과각성촉진영역 (hypothalamic orexin neurons) 의불안정에서기인하는것으로설명하였다 [13]. 이같은신경생리적과각성은다양한형태로나타나는데 1) 뇌파 (electroencephalogram, EEG) 에서베타파의증가와델타파의감소소견, 2) 내분비계에서수면전및수면동안코티졸및 adrenocorticotropic hormone (ACTH) 의증가, corticotrophin releasing factor (CRF) 의증가등 hypothalamic-pituitary-adrenal (HPA) 축의이상소견, 3) 수면및각성시 single photon emission computed tomography (SPECT) 및 positron emission tomography (PET) 검사에서대뇌당 (glucose) 대사율의증가소견, 4) 생리기능에서심박동증가, 심박동변이 (heart rate variability, HRV) 감소, 수면중전신대사율증가등이다 [6,12,14,15]. 이밖에도 Doghramji 등은심리학적모형으로프로이트의정신분석학모형에서꿈작업 (dream work) 과불면의관련성에대한설명, 불면증과인지- 행동적모형에서손상사건 (traumatic events) 및스트레스에의한인지및정서적각성이대부분의불면증환자에서소인으로작용한다고설명하고있다 [12]. 인지-행동모형에의하면불면증환자들은이완이어렵고, 정서적긴장및불안, 많은생각에지나치게집 Table 3. Precipitating and perpetuating factors of insomnia Precipitating factors Major life events (e.g., illness, separation) less severe but more chronic daily stress Temperament factors Anxiety or worry-prone personality or cognitive styles, increased arousal predisposition, and tendency to repress emotions Environmental factors Noise, light, uncomfortably high or low temperature, high altitude Genetic factors Female gender, advancing age, familial Moderating factors Poor sleep hygiene practices (e.g., excessive caffeine use, irregular sleep schedules), poor sleep habits, the fear of not sleeping Ref. 1 with permission from American Psychiatric Publishing. 206 http://www.e-hmr.org
안동현 불면증 : 원인과진단 착, 걱정및우울이높은특성, 수면에대한왜곡된믿음이소인으 로작용하면잠자리에서지나치게인지적인점검하는경향이지속 Table 4. Sleep/wake history in the evaluation of insomnia 1. Nature of the complaint of insomnia - Nocturnal pattern (initial, middle, terminal) - Onset, duration, frequency, severity, course - Precipitating and perpetuating factors - Past and current treatments and responses 2. Daytime consequences, activities and functions - Fatigue, irritability, anergia, memory impairment, mental slowing - Napping (number, time, duration) - Quality of life, mood disturbance, cognitive dysfunction, exacerbation of comorbid conditions 3. Habits and behaviors related to sleep and the sleep environment that aggravate insomnia - Caffeine and alcohol before bedtime, nicotine - Large meals, excessive fluid intake, or exercising within 3 hours of bedtime - Utilizing the bed for nonsleep activities (work, telephone, internet) - Staying in bed while awake for extended periods of time - Activating behaviors up to the point of bedtime - Excessive worrying at bedtime - Clock-watching before sleep onset or during nocturnal awakenings - Exposure to bright light prior to bedtime or during awakenings - Keeping the bedroom too hot or to cold - Noise - Behaviors of a bedpartner (e.g., snoring, leg movements) 4. Daytime habits and behaviors that aggravate insomnia - Prolonged bedrest, inactivity and excessive napping - Insufficient light exposure - Frequent travel and shift work 5. Patterns of sleep and nocturnal symptoms - Bedtime - Sleep latency (time to fall asleep after lights out) - Awakenings; number, characterization, duration; associated symptoms; associated behaviors - Final awakening, rising time(time out of bed) - Nocturnal symptoms (respiratory, motor, other medical, behavioral & psychological) Ref. 12 with permission from American Psychiatric Association. 요인으로작용한다고하였다. 이같이일부유전적요인, 신경생리적과각성요인과인지-행동적요인이소인, 유발요인, 및지속요인으로작용하여급성 / 상황적으로발생한불면이일부에서만성화되는것으로그병태생리를설명하고있고, 이들은 Table 3에요약되어있다. 5. 진단및평가불면증의진단은일차적으로임상적면담을통해얻어지는환자혹은보호자로부터얻어지는호소에근거하게된다. 임상적면담에서가장중요한것은불면호소의특성및이와관련한자세한병력청취로, Table 4에제시되어있는사항들을주의깊게확인하여야한다 [12,16]. 여기에덧붙여보조적으로여러방법들이사용되는데, 흔히수면일지 (sleep diary) 의작성과다양한설문지 (questionnaires) 가있다. Table 5에불면증진단및평가에흔히사용되는설문지를제시하였는데, 일부는국내에서도사용되지만, 일부는아직사용되고있지않다 [16-19]. 수면일지는취침시각, 잠드는데걸리는시간, 수면중각성, 기상시각, 전체수면시간, 낮잠, 음료및약물복용등에관한사항을매일기록하도록하는데진단뿐아니라치료경과를평가하는데도도움이된다. 수면및각성주기를추정할수있는운동량을측정하는기구로 actigraphy가있어수면-각성주기의장애의평가에는일부유용하지만불면증진단에는유용성이낮다 [20, 21]. 수면과각성을구별하고평가하는데가장민감한도구로서수면다원검사 (polysomnography, PSG) 가있지만, 고가이고여러가지전극을부착하는것으로인해수면무호흡증, 기면증등의진단및평가에는유용하지만불면증의진단적도구로서는그효용성이제한적이다. 불면증에서의 PSG 소견을보면수면잠복기 (sleep latency) 및잠든후각성시간의증가, 수면효율 (sleep efficiency) 의감소와 Table 5. Questionnaires and scales used in assessment of the patient with insomnia Questionnaire Author Characteristics and description Epworth Sleepiness Scale (ESS) Johns MW (1991, 1997) 8-item self report questionnaire used to assess subjective sleepiness (0-24; normal < 10) Insomnia Severity Index (ISS) Morin CM (2001) 7-item rating used to assess the patient s perception of insomnia, which is available in three forms Pittsburgh Sleep Quality Index (PSQI) Buysse DJ (1989) 19-item self report measure(and 5 additional items to be completed by a bed partner) of sleep quality (poor sleep: global score > 5) Fatigue Severity Scale (FSS) Krupp LB (1989) 9-item patient rating of daytime fatigue Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS) Functional Outcomes of Sleep Questionnaire (FOSQ) Women s Health Initiative Insomnia Rating Scale Morin (1994) Weaver TE (1997) Levine DW (2003) Sleep Diary Lichstein KL (2004) Self-rating questionnaire of 30 statements that is used to assess negative cognitions about sleep And an abbreviated version (16 items) using a more user-friendly response format (0-10, Likert-type scale; DBAS-16) was published in 2007. 30-items to assess the impact of excessive sleepiness on functional outcomes relevant to daily behaviors and sleep-related quality of life A shorter 10-item version, the FOSQ-10, was published in 2009. Five self-rated, multiple-choice questions to measure sleep disturbance during the previous month and to discriminate persons with insomnia from normal sleepers(0~20, insomnia > 9). http://www.e-hmr.org 207
Dong Hyun Ahn Insomnia: Causes and Diagnosis 같은수면지속성 (sleep continuity) 의이상과 1단계수면증가및 3,4 단계수면의감소와같은소견이나타날수있다. 그러나이러한수면의이상소견의심각도가환자의임상증상혹은주관적호소와항상일치하는것은아니다. 환자들은종종수면시간을과소추정하거나수면중각성을과대추정하는경향이있기때문이다. 이러한제한점으로미국수면학회에서는불면증의일반적인진단 (routine evaluation) 과정에서 PSG를적용하지않을것을권고하였다 [22]. 정량화뇌파분석 (quantitative electroencephalographic analysis, qeeg) 에서잠들기시작무렵및비급속안구운동 (non-rapid eye movement, NREM) 수면기에일반인에비해높은주파수의뇌파파워 (high frequency EEG power) 가많아지는것을나타내는수가있는데이는피질각성이증가된것을시사한다고할수있다. 하지만불면증환자중낮아진소견을보이는경우에는수면장애가없는사람과비교했을때객관적인수면실험실측정치에서주간졸림증의증가를보이지않는다. 그외에각성도의증가및 hypothalamic-pituitary-adrenal (HPA) axis의전반적활성화의소견들, 예를들면코티졸양, 심박동변이, 스트레스에대한반응도, 대사율의증가가아주일관되지는않지만이들에게서나타난다. 이들소견은전반적으로생리적및인지적긴장도의증가가불면증에중요한역할을한다고하는가설에부합한다 [2,6,12,14]. 결론및요약불면증은증상이기도하고, 개별질환이기도하다. 증상호소는신체질환이든정신질환이든환자군은물론일반인구에서도매우흔하지만, 막상개별질환으로의정의는분류체계에따라다소차이를보이고있다. 따라서발생빈도는어떤기준을적용하느냐에따라다소차이를보인다. 하지만어떤기준을적용하든지의사들은진료현장에서매우흔하게접할뿐더러많은질환혹은약물사용과도불면은밀접한연관을갖는다. 불면은개인적고통이나질병경과에영향을미칠분아니라, 불면에의한주간졸림증을포함한다양한영역에서많은영향을미쳐공중보건및보건경제학적으로도주목받고있다. 아직구체적인영향이나규모를정확하게측정한연구는적지만, 불면과관련한작업능률, 안전사고, 결근등에영향을미치고있다. 불면의진단및평가는정량화뇌파검사, 수면다원검사, actigraphy 등이연구되고는있지만그효용성에대해서는매우제한적인결과를갖는다. 여전히개인및보호자와의면담, 그리고보조적으로수면관련질문지, 수면일기등의방법이유용하다. 의사들은일차진료영역이든, 전문화된영역에서진료하든불면증은피할수없는임상적문제로이를정확하게진단하고평가할수있는능력을갖추어야한다. REFERENCES 1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Washington DC: American Psychiatric Publishing; 2013:361-422. 2. NIH State of the Science Conference statement on Manifestations and Management of Chronic Insomnia in Adults statement. J Clin Sleep Med 2005;1:412-21. 3. Thorpy MJ. Classification of sleep disorders. Neurotherapeutics 2012;9: 687-701. 4. Lee S, Cheong YS, Park EW, Choi EY, Yoo HK, Kang KH, et al. Prevalence of sleep disorder and associated factors in family practice. Korean J Fam Med 2010;31:837-44. 5. Cho YW, Shin WC, Yun CH, Hong SB, Kim J, Earley CJ. Epidemiology of insomnia in korean adults: prevalence and associated factors. J Clin Neurol 2009;5:20-3. 6. Mai E, Buysse DJ. Insomnia: Prevalence, Impact, Pathogenesis, Differential Diagnosis, and Evaluation. Sleep Med Clin 2008;3:167-74. 7. Green MJ, Espie CA, Hunt K, Benzeval M. The longitudinal course of insomnia symptoms: inequalities by sex and occupational class among two different age cohorts followed for 20 years in the west of Scotland. Sleep 2012;35:815-23. 8. Morin CM, Belanger L, LeBlanc M, Ivers H, Savard J, Espie CA, et al. The natural history of insomnia: a population-based 3-year longitudinal study. Arch Intern Med 2009;169:447-53. 9. Buysse DJ, Angst J, Gamma A, Ajdacic V, Eich D, Rossler W. Prevalence, course, and comorbidity of insomnia and depression in young adults. Sleep 2008;31:473-80. 10. LeBlanc M, Beaulieu-Bonneau S, Merette C, Savard J, Ivers H, Morin CM. Psychological and health-related quality of life factors associated with insomnia in a population-based sample. J Psychosom Res 2007;63:157-66. 11. Zhang J, Lam SP, Li SX, Li AM, Lai KY, Wing YK. Longitudinal course and outcome of chronic insomnia in Hong Kong Chinese children: a 5-year follow-up study of a community-based cohort. Sleep 2011;34:1395-402. 12. Doghramji K, Grewal R, Markov D. Evaluation and management of insomnia in the psychiatric setting. Focus 2009;7:441-54. 13. Riemann D, Spiegelhalder K, Espie C, Pollmacher T, Leger D, Bassetti C, et al. Chronic insomnia: clinical and research challenges--an agenda. Pharmacopsychiatry 2011;44:1-14. 14. Riemann D, Spiegelhalder K, Feige B, Voderholzer U, Berger M, Perlis M, et al. The hyperarousal model of insomnia: a review of the concept and its evidence. Sleep Med Rev 2010;14:19-31. 15. Bonnet MH, Arand DL. Hyperarousal and insomnia: state of the science. Sleep Med Rev 2010;14:9-15. 16. Schutte-Rodin S, Broch L, Buysse D, Dorsey C, Sateia M. Clinical guideline for the evaluation and management of chronic insomnia in adults. J Clin Sleep Med 2008;4:487-504. 17. Omachi TA. Measures of sleep in rheumatologic diseases: Epworth Sleepiness Scale (ESS), Functional Outcome of Sleep Questionnaire (FOSQ), Insomnia Severity Index (ISI), and Pittsburgh Sleep Quality Index (PSQI). Arthritis Care Res (Hoboken) 2011;63 Suppl 11:S287-96. 18. Benca R, Lichstein KL. Sleep disorders measures. In Rush AJ, First MB, Blacker D, eds. Handbook of psychiatric measures. 2nd ed. Washington, DC: American Psychiatric Publishing; 2008:649-66. 19. Morin CM, Vallieres A, Ivers H. Dysfunctional beliefs and attitudes about sleep (DBAS): validation of a brief version (DBAS-16). Sleep 2007;30:1547-54. 20. Morgenthaler T, Alessi C, Friedman L, Owens J, Kapur V, Boehlecke B, et al. Practice parameters for the use of actigraphy in the assessment of sleep 208 http://www.e-hmr.org
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