Emotional, behavioural problems and cigarette smoking in adolescence: findings of a Greek cross-sectional study
© Giannakopoulos et al; licensee BioMed Central Ltd. 2010
Received: 20 September 2009
Accepted: 3 February 2010
Published: 3 February 2010
Although several studies have reported findings concerning the association between smoking and emotional/behavioural problems, little research has investigated this association after controlling for confounding factors which have been found to be significantly correlated with both cigarette smoking and emotional/behavioural problems and may have a strong effect on the relationship between adolescents' mental health and smoking. The present study attempted to assess the association between adolescents' smoking status and their emotional/behavioural problems after controlling for a number of possible confounders (i.e. age, gender, parental smoking status, exposure to family smoking, family socioeconomic status, adolescents' leisure time) in a Greek nation-wide school-based sample.
Participants completed a questionnaire which retrieved information about age, gender, family socioeconomic status, smoking status, parental smoking, adolescents' leisure time and emotional/behavioural problems. Data were modelled using multiple logistic regression analysis with adolescents' smoking status as the dependent variable.
A total of 1194 (i.e. 63% response rate) of self-reported questionnaires (40.1% boys, 59.9% girls; 12-18 years old) were returned. Data from 1030 participants with full data were analyzed. Cigarette smoking was strongly associated with higher levels of emotional/behavioural problems (p < 0.001) and the association was not moderated (OR = 1.13, 95% CI: 1.08-1.18) after controlling for the effects of other covariates. Emotional symptoms, conduct problems and hyperactivity/inattention were all significantly associated with adolescents' current smoking.
This study supports the association between smoking and emotional/behavioural problems among adolescents. Addressing adolescents' needs regarding their emotional/behavioural health could be helpful in the development of effective anti-smoking strategies in school environment and elsewhere.
Cigarette smoking is a leading cause of morbidity and premature death in European countries with the majority (80-90%) of adult smokers beginning to smoke before 18 years of age . In Greece, the prevalence of smoking in middle school adolescents is high. According to the Global Youth Tobacco Survey which was implemented during the academic year 2004-2005, about one-third of the students (aged 13-15 years) reported that they had tried tobacco in the past, while 16.20% reported being current users of tobacco products . Another study  on alcohol and other drug use among students in 35 European countries has reported that lifetime smoking among the Greek students is below European average (50% vs. 66%), and the 30-day prevalence of smoking has the same tendency (28% compared with 35%). However, smoking in Greek adolescents constitutes an increasing problem in the absence of planned combined efforts through anti-smoking policies and tobacco control interventions . The thorough investigation of the psychosocial context in which adolescent smoking appears is an essential process in developing well-designed smoking prevention interventions.
A number of epidemiological studies have examined the association of cigarette smoking with psychiatric disorders in adolescence. Conduct disorders, attention-deficit/hyperactivity disorder (ADHD) and clinical levels of aggression have been consistently related to adolescents' regular smoking [5–21]. A large Chinese study in a sample of 1360 adolescents has found that externalizing problems were significantly associated with ever smoking (OR = 1.60, 95% CI: 1.00-2.60) after adjustment for sociodemographic covariates and life stress . Similarly, a Dutch population-based study among 5938 adolescents  has reported that adolescents with depressive feelings were more likely to report lifetime smoking (OR = 1.73, 95% CI: 1.46-2.05), and more likely to report regular smoking (OR = 2.06, 95% CI: 1.55-2.74) than those without depressive feelings. Significant effects were also found for age and education. However, the findings about internalizing disorders, such as depression and anxiety, are somewhat contradictory with some studies indicating a significant relationship between these disorders and smoking [5, 23–25], while others did not manage to confirm a significant association [26–29]. Moreover, most of the reported studies have not examined the association of emotional/behavioural problems and tobacco use after controlling for confounding factors beyond age, gender and education, such as family socioeconomic status, parental smoking and adolescents' leisure time which have been found to be significantly correlated with both cigarette smoking and emotional/behavioural problems and may have a strong effect on the relationship between adolescents' mental health and smoking [30–33].
The present study was an effort to extend previous research through assessing smoking status, emotional/behavioural problems, and a number of other variables (i.e. adolescents' age and gender, family socioeconomic status, parental smoking, and adolescents' leisure time) in a Greek nation-wide school-based sample of adolescents. Given the relatively few previous studies on this issue, the present large survey attempted to contribute to a broader insight into the relationship between cigarette smoking and emotional/behavioural problems.
Participants and procedure
This study was conducted in the year 2003 within the framework of the European project 'Screening and Promotion for Health-Related Quality of Life (HRQoL) in Children and Adolescents: A European Public Health Perspective' . The school sampling in Greece was random, multi-staged and performed to take into account distribution of the target population by age and administrative school region. The target population was adolescents aged 12 to 18. A sample size of 1800 adolescents was considered necessary to detect a minimally important difference of half a standard deviation (SD) in HRQoL scores within each age strata between children with and without special healthcare needs or a chronic condition. A response rate of approximately 70% was expected, so the initial sample size was set at 2400 children and adolescents. In Greece, ages 12 to 18 correspond to six secondary school grades. Approximately 400 students were included from each of the 6 age groups/grades in order to reach the original target of 2400 adolescents. For example, the total number of students in Greece attending the first grade of the secondary school is 119055. If an administrative region had a total number of 2174 students attending the first grade of the secondary school, then eight students were randomly recruited from a school in that region ((2174 × 400)/119055 = 7.60 students). Each age group/grade had been calculating accordingly, for each sector. Schools in each sector were randomly selected by a computer program and students of each selected school were selected randomly from classroom name lists. Inclusion criteria were adequate reading skills. A sample of 1900 adolescents (12 to 18 year olds) was recruited. Students were asked to complete the questionnaire at home after providing written informed consent. Ethical approval was attained from the National Ministry of Education.
Adolescent and parental smoking status
Adolescents' smoking was assessed by questioning the participants "How often do you currently smoke cigarettes (or tobacco)?" Answer categories ranged from never to everyday. Parental smoking was assessed by questioning adolescents "Does your father smoke?" and "Does your mother smoke?" Answer categories were: yes/no. Additionally, participants were asked if any family member smoked in the place where adolescents did their homework or spent their free time. Answer categories were: yes/no.
Family socioeconomic status
To assess SES, the Family Affluence Scale [FAS;] was used, addressing issues of family car ownership, having their own unshared room, the number of computers at home and time the adolescent spent on holiday in the past 12 months.The FAS was collected from adolescents in seven categories (from 0 the lowest, to 7 the highest FAS category) and was re-coded into three groups in the analysis (low FAS level (0-3), intermediate (4-5) and high FAS level (6-7)). The psychometric properties of the FAS are acceptable and support its use as a self-reported adolescents' measure .
Adolescents' leisure time
Adolescents' leisure time was measured using the dimension 'autonomy' of KIDSCREEN-52, a generic self-reported questionnaire with good psychometric properties . This specific dimension was selected since previous literature has shown that leisure time is significantly associated with adolescents' smoking status . This dimension is intended to explore the opportunity given to adolescents to create their social and leisure time. In particular, the extent to which adolescents feel able to shape their own life as well as being able to make decisions about day to day activities is considered. The dimension also examines if adolescents feel sufficiently provided with opportunities to participate in social activities particularly in leisure activities and pastimes. It consists of 5 items, with formats using a 5-point Likert response scale and the recall period being 1 week. Rasch scores are computed and transformed into T-values with a mean of 50 and a standard deviation of 10; higher scores indicate better physical well-being. The internal consistency coefficient for the autonomy score was 0.84 in the present sample.
Adolescents' emotional/behavioural problems
To assess adolescents' emotional/behavioural problems, the Strengths and Difficulties Questionnaire (SDQ)  was used. The SDQ contains 25 items (small sentences), categorized into five scales of five items each: hyperactivity/inattention, emotional symptoms, conduct problems, peer problems and prosocial behaviour. Responses to each of the 25 items consisted of three options: not true, somewhat true, or certainly true. For all scales the items that are worded negatively are assigned scores of 2 for certainly true, 1 for somewhat true, and 0 for not true. All but the last scale can be summed up to a total difficulties score ranging from 0 to 40. The version for youths was used in the present study. In order to combat inherent weaknesses of cross-cultural adaptation (e.g., semantic and scale equivalence) the research team in the present study followed a standardized translation methodology according to international cross-cultural translation guidelines . The internal consistency coefficient for the total difficulties score was 0.77. Cronbach's alphas for the prosocial behaviour, emotional symptoms and hyperactivity-inattention were 0.72, 0.73 and 0.63, respectively. The lowest alpha was found on the peer problems (0.50) and conduct problems scale (0.56) in the present sample .
Analyses were conducted concerning full data without missing values. Missing data counted less than 5% for each variable, but concerning all variables 1030 participants out of 1194 with full data were analyzed and reported. Continuous variables are presented with mean and standard deviation, while discreet variables are presented with absolute and relative frequencies. For the comparisons of proportions chi-square tests were used. Student's t-tests were computed for the comparison of mean values. Differences on SDQ scales according to smoking status were determined by the use of multivariate analysis of variance (MANOVA). Data were modelled using multiple logistic regression analysis with adolescents' smoking status as the dependent variable. The regression equation included terms for gender, age, KIDSCREEN-52 'autonomy' dimension, SDQ total difficulties scale, FAS, father's and mother's smoking status and family member's smoking in the place that adolescents do their homework or spend their free time. Adjusted odds ratios with 95% confidence intervals were computed from the results of the logistic regression analyses. Model diagnostics were evaluated using the Hosmer and Lemeshow statistic. All p-values reported are two-tailed. Statistical significance was set at 0.05 and analyses were conducted using SPSS statistical software (version 13.0).
Family socioeconomic status
Exposure to family members' smoking
Less than once a week
At least once a week
Sample characteristics by smoking status
P χ2 test
Family socioeconomic status
Exposure to family members' smoking
Leisure time, mean (SD)
Means and standard deviations of the Strengths and Difficulties Questionnaire (SDQ) scales by smoking status
F (df: 1, 1026)
Results from multiple logistic regression that evaluated demographic/family factors and emotional/behavioural problems in relation to the presence of smoking habits
Family socioeconomic status
Exposure to family members' smoking
Leisure time (for one unit increase)
SDQ total difficulties (for one unit increase)
Results from multiple logistic regression that evaluated emotional/behavioural problems in relation to the presence of smoking habits
The present study investigated cigarette smoking among a Greek nation-wide school-based sample of adolescents and the relationship between cigarette smoking status and adolescents' emotional/behavioural problems while considering the potential confounding effects of other important factors (i.e. age, gender, socioeconomic status, parental smoking, leisure time) in order to obtain a more accurate account of this widely reported association. The prevalence rates of current smoking for adolescents aged 12-15 years and those aged 16-18 years were found comparable (i.e. approx. 4% and 24% respectively) to those reported in other Greek studies [2, 31]. The frequency of current smokers was significantly higher among adolescents from low family socioeconomic background and with a smoking parent. These findings are consistent with previous data [30–32]. However, the present study could not detect any significant association between smoking status and adolescents' leisure time . The measurement of leisure time applied here may account for this finding, since it did not include data regarding parental control and surveillance over adolescents' activities outside school and family. Cigarette smoking was associated with higher levels of emotional/behavioural problems and the association was not moderated after controlling for the effects of other covariates. Emotional symptoms, conduct problems and hyperactivity/inattention were all significantly associated with adolescents' current smoking, lending further support to existing literature [5–21, 23–25]. This result also suggests that the association between smoking and emotional/behavioural problems is not confounded by significant predictors for both adolescents' smoking and emotional/behavioural problems, such as age, socioeconomic status and parental smoking.
The reported relationships underlie the fact that it is often the same individuals who engage in risk behaviours such as smoking and present emotional/behavioural difficulties, increasing the harmful effect of these behaviours on human health. The present findings highlight the importance of addressing adolescents' mental health problems in any effective effort for preventing or combating adolescents' cigarette smoking. Instead of dealing with smoking as a more or less normative risky behaviour during this critical period or focusing mainly on peer influences, adolescent health professionals should take into account the complex cluster of problems and needs which possibly burden adolescents and eventually remain unmet.
Certain limitations should be considered in understanding the results of the present study. The cross-sectional design of the study could not demonstrate causal directions between smoking and emotional/behavioural problems. Additionally, as is frequently observed in school-based surveys, there was a tendency for a higher response rate from girls compared with boys. It should be stressed, however, that the methodology of the European project, within which the present study was conducted, achieved a sufficient degree of representativeness to provide reference population values, as provided elsewhere . Moreover, it is possible that factors other than the variables included in the statistical analyses are related to the associations between smoking and emotional/behavioural problems. For example, genetic factors, smoking habits during pregnancy, peers' smoking and personality variables (e.g. coping styles, affect regulation, risk-taking) could mediate or moderate the abovementioned relationship. Finally, tobacco use was not assessed through elaborated measures of smoking behaviour (tracking initiation age and frequency with a longitudinal design), which may have misclassified the smoking status with consequences on the observed associations.
This study, along with previous research, supports the association between smoking and emotional/behavioural problems among adolescents. Addressing adolescents' needs regarding their emotional/behavioural health could be helpful in the development of effective anti-smoking strategies in school environment and elsewhere. Targeting vulnerable groups, such as socioeconomically disadvantaged adolescents or children with smoking family members should be combined with a thorough attempt to respond to concurrent emotional/behavioural problems in order to both promote a smoke-free lifestyle and enhance general wellbeing and functioning. Reversely, smoking in adolescence should be considered as a possible indicator for emotional/behavioural problems and thus, can help peers, parents and teachers be aware of adolescents at risk for problems such as emotional/behavioural difficulties which may be difficult to identify.
- Mackenbach JP, Stirbu I, Roskam AJ, Schaap MM, Menvielle G, Leinsalu M, Kunst AE: Socioeconomic inequalities in health in 22 European countries. N Engl J Med. 2008, 358: 2468-2481. 10.1056/NEJMsa0707519.View ArticlePubMedGoogle Scholar
- Kyrlesi A, Soteriades ES, Warren CW, Kremastinou J, Papastergiou P, Jones NR, Hadjichristodoulou C: Tobacco use among students aged 13-15 years in Greece: the GYTS project. BMC Public Health. 2007, 7: 3-10.1186/1471-2458-7-3.View ArticlePubMedPubMed CentralGoogle Scholar
- Hibell B, Andersson B, Bjarnason T, Ahlstrfm S, Balakireva O, Kokkevi A, Morgan M: Alcohol and other drugs among students in 35 European Countries. The ESPAD Report 2003. 2004, Stockholm: CANGoogle Scholar
- Koumi I, Tsiantis J: Smoking trends in adolescence: report on a Greek school-based, peer-led intervention aimed at prevention. Health Promot Int. 2001, 16: 65-72. 10.1093/heapro/16.1.65.View ArticlePubMedGoogle Scholar
- Liu X: Cigarette smoking, life stress, and behavioral problems in Chinese adolescents. J Adolesc Health. 2003, 33: 189-192. 10.1016/S1054-139X(03)00020-X.View ArticlePubMedGoogle Scholar
- Audrain-McGovern J, Rodriguez D, Tercyak KP, Cuevas J, Rodgers K, Patterson F: Identifying and characterizing adolescent smoking trajectories. Cancer Epidemiol Biomarkers Prev. 2004, 13: 2023-2034.PubMedGoogle Scholar
- Crone MR, Reijneveld SA: The association of behavioural and emotional problems with tobacco use in adolescence. Addict Behav. 2007, 32: 1692-1698. 10.1016/j.addbeh.2006.11.006.View ArticlePubMedGoogle Scholar
- Sacco KA, Bannon KL, George TP: Nicotinic receptor mechanisms and cognition in normal states and neuropsychiatric disorders. J Psychopharmacol. 2004, 18: 457-474. 10.1177/0269881104047273.View ArticlePubMedPubMed CentralGoogle Scholar
- Burt RD, Dinh KT, Peterson AV, Sarason IG: Predicting adolescent smoking: a prospective study of personality variables. Prev Med. 2000, 30: 115-125. 10.1006/pmed.1999.0605.View ArticlePubMedGoogle Scholar
- Masse LC, Tremblay RE: Behavior of boys in kindergarten and the onset of substance use during adolescence. Arch Gen Psychiatry. 1997, 54: 62-68.View ArticlePubMedGoogle Scholar
- Brook DW, Brook JS, Zhang C, Whiteman M, Cohen P, Finch SJ: Developmental trajectories of cigarette smoking from adolescence to the early thirties: personality and behavioral risk factors. Nicotine Tob Res. 2008, 10: 1283-1291. 10.1080/14622200802238993.View ArticlePubMedPubMed CentralGoogle Scholar
- Dani JA, Harris RA: Nicotine addiction and comorbidity with alcohol abuse and mental illness. Nat Neurosci. 2005, 8: 1465-1470. 10.1038/nn1580.View ArticlePubMedGoogle Scholar
- Elkins IJ, McGue M, Iacono WG: Prospective effects of attention-deficit/hyperactivity disorder, conduct disorder, and sex on adolescent substance use and abuse. Arch Gen Psychiatry. 2007, 64: 1145-1152. 10.1001/archpsyc.64.10.1145.View ArticlePubMedGoogle Scholar
- Galera C, Bouvard MP, Messiah A, Fombonne E: Hyperactivity-inattention symptoms in childhood and substance use in adolescence: the youth gazel cohort. Drug Alcohol Depend. 2008, 94: 30-37. 10.1016/j.drugalcdep.2007.09.022.View ArticlePubMedGoogle Scholar
- Gardner TW, Dishion TJ, Posner MI: Attention and adolescent tobacco use: A potential self-regulatory dynamic underlying nicotine addiction. Addict Behav. 2006, 31: 531-536. 10.1016/j.addbeh.2005.05.018.View ArticlePubMedGoogle Scholar
- Kollins SH, McClernon FJ, Fuemmeler BF: Association between smoking and attention-deficit/hyperactivity disorder symptoms in a population-based sample of young adults. Arch Gen Psychiatry. 2005, 62: 1142-1147. 10.1001/archpsyc.62.10.1142.View ArticlePubMedGoogle Scholar
- Monuteaux MC, Faraone SV, Hammerness P, Wilens TE, Fraire M, Biederman J: The familial association between cigarette smoking and ADHD: a study of clinically referred girls with and without ADHD, and their families. Nicotine Tob Res. 2008, 10: 1549-1558. 10.1080/14622200802326137.View ArticlePubMedGoogle Scholar
- Rodriguez D, Tercyak KP, Audrain-McGovern J: Effects of inattention and hyperactivity/impulsivity symptoms on development of nicotine dependence from mid adolescence to young adulthood. J Pediatr Psychol. 2008, 33: 563-575. 10.1093/jpepsy/jsm100.View ArticlePubMedGoogle Scholar
- Sartor CE, Xian H, Scherrer JF, Lynskey MT, Duncan AE, Haber JR, Grant JD, Bucholz KK, Jacob T: Psychiatric and familial predictors of transition times between smoking stages: results from an offspring-of-twins study. Addict Behav. 2008, 33: 235-251. 10.1016/j.addbeh.2007.09.002.View ArticlePubMedGoogle Scholar
- Whalen CK, Jamner LD, Henker B, Delfino RJ, Lozano JM: The ADHD spectrum and everyday life: experience sampling of adolescent moods, activities, smoking, and drinking. Child Dev. 2002, 73: 209-227. 10.1111/1467-8624.00401.View ArticlePubMedGoogle Scholar
- Clark DB, Jones BL, Wood DS, Cornelius JR: Substance use disorder trajectory classes: diachronic integration of onset age, severity, and course. Addict Behav. 2006, 31: 995-1009. 10.1016/j.addbeh.2006.03.016.View ArticlePubMedGoogle Scholar
- Otten R, Engels RC, Prinstein MJ: A prospective study of perception in adolescent smoking. J Adolesc Health. 2009, 44: 478-484. 10.1016/j.jadohealth.2008.09.004.View ArticlePubMedGoogle Scholar
- Patton GC, Carlin JB, Coffey C, Wolfe R, Hibbert M, Bowes G: Depression, anxiety, and smoking initiation: a prospective study over 3 years. Am J Public Health. 1998, 88: 1518-1522. 10.2105/AJPH.88.10.1518.View ArticlePubMedPubMed CentralGoogle Scholar
- Lerman C, Audrain J, Orleans CT, Boyd R, Gold K, Main D, Caporaso N: Investigation of mechanisms linking depressed mood to nicotine dependence. Addict Behav. 1996, 21: 9-19. 10.1016/0306-4603(95)00032-1.View ArticlePubMedGoogle Scholar
- Sonntag H, Wittchen HU, Hofler M, Kessler RC, Stein MB: Are social fears and DSM-IV social anxiety disorder associated with smoking and nicotine dependence in adolescents and young adults?. Eur Psychiatry. 2000, 15: 67-74. 10.1016/S0924-9338(00)00209-1.View ArticlePubMedGoogle Scholar
- Dierker LC, Avenevoli S, Merikangas KR, Flaherty BP, Stolar M: Association between psychiatric disorders and the progression of tobacco use behaviors. J Am Acad Child Adolesc Psychiatry. 2001, 40: 1159-1167. 10.1097/00004583-200110000-00009.View ArticlePubMedGoogle Scholar
- Dierker LC, Avenevoli S, Stolar M, Merikangas KR: Smoking and depression: an examination of mechanisms of comorbidity. Am J Psychiatry. 2002, 159: 947-953. 10.1176/appi.ajp.159.6.947.View ArticlePubMedGoogle Scholar
- Clark DB, Cornelius JR: Childhood psychopathology and adolescent cigarette smoking: A prospective survival analysis in children at high risk for substance use disorders. Addictive Behaviors. 2004, 29: 837-841. 10.1016/j.addbeh.2004.02.019.View ArticlePubMedGoogle Scholar
- Clark DB, Kirisci L, Moss HB: Early adolescent gateway drug use in sons of fathers with substance use disorders. Addict Behav. 1998, 23: 561-566. 10.1016/S0306-4603(98)00038-0.View ArticlePubMedGoogle Scholar
- De Vries H: Socio-economic differences in smoking: Dutch adolescents' beliefs and behaviour. Social Science & Medicine. 1995, 41: 419-424.View ArticleGoogle Scholar
- Giannakopoulos G, Panagiotakos D, Mihas C, Tountas Y: Adolescent smoking and health-related behaviours: interrelations in a Greek school-based sample. Child Care Health Dev. 2009, 35: 164-170. 10.1111/j.1365-2214.2008.00906.x.View ArticlePubMedGoogle Scholar
- Skinner ML, Haggerty KP, Catalano RF: Parental and peer influences on teen smoking: Are White and Black families different?. Nicotine Tob Res. 2009, 11: 558-563. 10.1093/ntr/ntp034.View ArticlePubMedPubMed CentralGoogle Scholar
- Giannakopoulos G, Mihas C, Dimitrakaki C, Tountas Y: Family correlates of adolescents' emotional/behavioural problems: evidence from a Greek school-based sample. Acta Paediatr. 2009, 98: 1319-1323. 10.1111/j.1651-2227.2009.01314.x.View ArticlePubMedGoogle Scholar
- Berra S, Ravens-Sieberer U, Erhart M, Tebe C, Bisegger C, Duer W, von Rueden U, Herdman M, Alonso J, Rajmil L: Methods and representativeness of a European survey in children and adolescents: the KIDSCREEN study. BMC Public Health. 2007, 7 (182):
- Currie CE, Elton RA, Todd J, Platt S: Indicators of socioeconomic status for adolescents: the WHO Health Behaviour in School-aged Children Survey. Health Education Research. 1997, 12: 385-397. 10.1093/her/12.3.385.View ArticlePubMedGoogle Scholar
- Torsheim T, Currie C, Boyce W, Samdal O: Country material distribution and adolescents' perceived health: multilevel study of adolescents in 27 countries. Journal of Epidemiology and Community Health. 2006, 60: 156-161. 10.1136/jech.2005.037655.View ArticlePubMedPubMed CentralGoogle Scholar
- Ravens-Sieberer U, Gosch A, Rajmil L, Erhart M, Bruil J, Duer W, et al: KIDSCREEN-52 quality-of-life measure for children and adolescents. Expert Review of Pharmacoeconomic Outcomes Research. 2005, 5: 353-364. 10.1586/14737188.8.131.523.View ArticleGoogle Scholar
- Goodman R: The Strengths and Difficulties Questionnaire: a research note. Journal of Child Psychology and Psychiatry. 1997, 38: 581-586. 10.1111/j.1469-7610.1997.tb01545.x.View ArticlePubMedGoogle Scholar
- Bullinger M, Anderson R, Cella D, Aaronson N: Developing and evaluating cross-cultural instruments from minimum requirements to optimal models. Quality of Life Research. 1993, 2: 451-459. 10.1007/BF00422219.View ArticlePubMedGoogle Scholar
- Giannakopoulos G, Tzavara C, Dimitrakaki C, Kolaitis G, Rotsika V, Tountas Y: The factor structure of the Strengths and Difficulties Questionnaire (SDQ) in Greek adolescents. Ann Gen Psychiatry. 2009, 8: 20-10.1186/1744-859X-8-20.View ArticlePubMedPubMed CentralGoogle Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2458/10/57/prepub
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.