Ana Adan

Bio: Ana Adan is an academic researcher from University of Barcelona. The author has contributed to research in topics: Personality & Dual diagnosis. The author has an hindex of 39, co-authored 154 publications receiving 5949 citations. Previous affiliations of Ana Adan include Autonomous University of Barcelona.

Circadian typology: a comprehensive review.

Abstract: The interest in the systematic study of the circadian typology (CT) is relatively recent and has developed rapidly in the two last decades. All the existing data suggest that this individual difference affects our biological and psychological functioning, not only in health, but also in disease. In the present study, we review the current literature concerning the psychometric properties and validity of CT measures as well as individual, environmental and genetic factors that influence the CT. We present a brief overview of the biological markers that are used to define differences between CT groups (sleep-wake cycle, body temperature, cortisol and melatonin), and we assess the implications for CT and adjustment to shiftwork and jet lag. We also review the differences between CT in terms of cognitive abilities, personality traits and the incidence of psychiatric disorders. When necessary, we have emphasized the methodological limitations that exist today and suggested some future avenues of work in order to overcome these. This is a new field of interest to professionals in many different areas (research, labor, academic and clinical), and this review provides a state of the art discussion to allow professionals to integrate chronobiological aspects of human behavior into their daily practice.

Gender differences in morningness–eveningness preference

Abstract: Morningness - eveningness preference (morning-, intermediate-, evening- type) or circadian typology is the individual difference that most clearly explains the variations in the rhythmic expression of biological or behavioral patterns. The aim of this study was to analyze gender difference in morningness - eveningness preference using the Horne and Ostberg questionnaire in the largest university student population selected so far ðN ¼ 2135Þ; with an age range 18 -30 yr. Morningness -eveningness questionnaire (MEQ) score distribution closely correlated to the normal curve ðrange ¼ 17 - 78; mean ¼ 48:25; SD ¼ 10:11Þ; with 338 (15.84%) morning-types, 1273 (59.62%) intermediate-types, and 524 (24.54%) evening-types. The men and women differed significantly in their mean scores ðp , 0:0001Þ and distribution per circadian typology ðp , 0:00001Þ; with the men presenting a more pronounced eveningness preference. Three factors were identified by factor analysis: time of greatest efficiency (I), sleep time/sleep phase (II), awakening time/sleep inertia (III). The MEQ items sensitive to gender differences were essentially those included in factor I and factor II. The results are discussed in relation to recent models of circadian regulation of the sleep - wake cycle. (Chronobiology International, 19(4), 709-720, 2002)

Chronotype and personality factors in the daily consumption of alcohol and psychostimulants

Abstract: This paper analyses the influence of and possible interaction between chronotype (Morning-types, Neither-types and Evening-types} and personality dimensions (neuroticism, extroversion and psychoticism) in the daily consumption of alcohol and psychostimulants (nicotine and caffeine). In a sample of 537 subjects (257 men and 280 women), who were students and professionals with different but fixed work schedules, there were significant differences among the chronotypes regarding the consumption of all the above. Evening-types consumed more alcohol, nicotine and caffeine (coffee and cola), while Morning-types consumed more caffeine from tea. Personality was only related to the consumption of cola: the greater the neuroticism the higher the consumption of this beverage. Stimulant drinks showed various types of interaction with personality types, which revealed a complex pattern of group action. The results stress the need to consider chronotype as a contributory psychological factor in a multi-causal model of consumption of psychoactive substances.

Social Jetlag: Misalignment of Biological and Social Time

Abstract: Humans show large differences in the preferred timing of their sleep and activity. This so-called "chronotype" is largely regulated by the circadian clock. Both genetic variations in clock genes and environmental influences contribute to the distribution of chronotypes in a given population, ranging from extreme early types to extreme late types with the majority falling between these extremes. Social (e.g., school and work) schedules interfere considerably with individual sleep preferences in the majority of the population. Late chronotypes show the largest differences in sleep timing between work and free days leading to a considerable sleep debt on work days, for which they compensate on free days. The discrepancy between work and free days, between social and biological time, can be described as 'social jetlag.' Here, we explore how sleep quality and psychological wellbeing are associated with individual chronotype and/or social jetlag. A total of 501 volunteers filled out the Munich ChronoType Questionnaire (MCTQ) as well as additional questionnaires on: (i) sleep quality (SF-A), (ii) current psychological wellbeing (Basler Befindlichkeitsbogen), (iii) retrospective psychological wellbeing over the past week (POMS), and (iv) consumption of stimulants (e.g., caffeine, nicotine, and alcohol). Associations of chronotype, wellbeing, and stimulant consumption are strongest in teenagers and young adults up to age 25 yrs. The most striking correlation exists between chronotype and smoking, which is significantly higher in late chronotypes of all ages (except for those in retirement). We show these correlations are most probably a consequence of social jetlag, i.e., the discrepancies between social and biological timing rather than a simple association to different chronotypes. Our results strongly suggest that work (and school) schedules should be adapted to chronotype whenever possible.

Contributions to Neuropsychological Assessment

Abstract: on to develop full blown Parkinson's disease with rigidity and bradykinesia in the next few years. For those interested in the mechanisms of tremor, there are the customary authoritative reviews by Llinas, De Long, Lamarre, Rothwell and Deuschl, but uncertainty remains with respect to the relative importance of central autonomous generators and instability of peripheral reflex loops. Well written chapters are also included on primary orthostatic tremor and its relationship to essential tremor, writing tremor, neuropathic tremor, midbrain tremor and the increasingly acknowledged psychogenic tremors. Complex interrelationship between dystonia and postural tremor is also covered in depth. This cornucopia will be coveted and dipped into by those neurologists with a special interest in abnormal movement disorders, but who would not consider themselves to have a research interest in tremor. However, for the majority of clinicians involved in the hurly burly of clinical practice, I suspect that regrettably time and cost factors will conspire together to keep this excellent book out of reach. ANDREW LEES

Circadian typology: a comprehensive review.

Abstract: The interest in the systematic study of the circadian typology (CT) is relatively recent and has developed rapidly in the two last decades. All the existing data suggest that this individual difference affects our biological and psychological functioning, not only in health, but also in disease. In the present study, we review the current literature concerning the psychometric properties and validity of CT measures as well as individual, environmental and genetic factors that influence the CT. We present a brief overview of the biological markers that are used to define differences between CT groups (sleep-wake cycle, body temperature, cortisol and melatonin), and we assess the implications for CT and adjustment to shiftwork and jet lag. We also review the differences between CT in terms of cognitive abilities, personality traits and the incidence of psychiatric disorders. When necessary, we have emphasized the methodological limitations that exist today and suggested some future avenues of work in order to overcome these. This is a new field of interest to professionals in many different areas (research, labor, academic and clinical), and this review provides a state of the art discussion to allow professionals to integrate chronobiological aspects of human behavior into their daily practice.