it is well established that exposure to familial adversities and environmental instability during upbringing are associated with subsequently increased risks of psychopathology and other negative outcomes ( boynton - jarrett et  al . , 2013 , , 1998 , green et  al . , 2010 , kessler et  al . , 2010 ) . residential changes during childhood , which could entail familial , school , social and routine disruptions , have been linked to poor mental health , psychological distress ( brown et  al . , 2012 , jelleyman and spencer , 2008 , tseliou et  al . , 2015 ) , suicidal behavior ( potter et  al . , 2001 , qin et  al . , 2009 ) , violence ( haynie and south , 2005 ) , poorer educational attainment ( pribesh and downey , 1999 ) and early initiation of illicit drug use ( dewit , 1998 ) . in the united states , 14% of children under aged 15 years moved homes during 20142015 ( united states census bureau , 2015 ) . residential mobility is thus quite common during upbringing . despite the large body of literature documenting the links between childhood residential moves and risks of subsequent psychopathology , associations with the development of specific psychiatric illnesses across the full spectrum of disorder are currently unknown . furthermore , no previous studies have examined a broad array of psychiatric diagnostic outcomes in the same cohort to enable direct comparison of these risks . childhood residential mobility has been linked to a higher prevalence of drug misuse and related problems in adulthood ( dewit , 1998 ) , and increased risk of developing depression ( gilman et  al . however , these studies , while valuable , were often limited in accuracy regarding exposure measurement , length of follow - up , or statistical power . they were also susceptible to recall bias , or they only examined the total number of moves through childhood , leaving ambiguity as to whether risks of developing disorders vary according to age at exposure to residential mobility . using prospective data from the national danish registers that were free of many of the methodological limitations mentioned above , paksarian et  al . ( 2015 ) investigated the links between childhood residential mobility and subsequent risk of schizophrenia and bipolar disorder onset . after adjusting for familial confounders , the study found that residential mobility each year from age 1 to 14 years was associated with raised risk of schizophrenia , while associations with bipolar disorder were weaker and less widespread across the exposure - age spectrum . ( in press ) found that childhood residential mobility was linked to elevated risk of multiple adverse outcomes occurring from mid - adolescence until early middle age , including attempted suicide , violent offending and premature death . denmark is the only country in the world to have complete nationwide longitudinal information on residential location , thus providing a unique opportunity to conduct studies of this kind . ( in press ) , investigating the links between childhood residential mobility and the subsequent development of a broad range of psychiatric disorders including:(1)any substance misuse disorders ; specifically alcohol misuse , and cannabis misuse(2)any personality disorders ; specifically antisocial personality disorder , and borderline personality disorder(3)schizophrenia and related disorders ( hereafter  broad schizophrenia ) ; specifically schizophrenia ( hereafter  narrow schizophrenia ) , and schizoaffective disorder(4)any mood disorders ; specifically bipolar disorder , and depressive disorder(5)any anxiety and somatoform disorders ; specifically obsessive compulsive disorder ( ocd)(6)any eating disorders ; specifically anorexia nervosa . any substance misuse disorders ; specifically alcohol misuse , and cannabis misuse any personality disorders ; specifically antisocial personality disorder , and borderline personality disorder schizophrenia and related disorders ( hereafter  broad schizophrenia ) ; specifically schizophrenia ( hereafter  narrow schizophrenia ) , and schizoaffective disorder any mood disorders ; specifically bipolar disorder , and depressive disorder any anxiety and somatoform disorders ; specifically obsessive compulsive disorder ( ocd ) any eating disorders ; specifically anorexia nervosa . since 1968 the civil registration system has registered all persons living in denmark ( pedersen et  al . , 2006 ) . it captures information such as date and place of birth , identity of parents and siblings , and continuously updated information on vital status and place of residence . the unique personal identification number assigned to every resident enables accurate linkage across all national registers . our study population included all persons born in denmark to danish - born parents during 19711997 , who were residing in the country on their 15th birthday ( n  =  1,439,363 ) . approval to conduct this study was granted formally by the danish data protection agency ( file number 2013 - 41 - 2265 ) , and data access was agreed by the state serum institute and statistics denmark ( fse i d 820 ) . since this project was based exclusively on registry data it did not need approval from the danish national committee on health research ethics . according to the danish act on processing of personal data , section 10 , this also meant that the investigators were not required to obtain informed consent from persons in the study population . residential changes were defined as moves between any of the 276 municipalities in denmark , using boundaries defined before the 2007 municipality reform , which reduced the number of municipalities from 276 to 96 . ( 2015 ) . to focus on moves that may have greater psychological impact , change of address within the same municipality was not investigated ( pedersen and mortensen , 2001a ) . for each person in the study cohort , we calculated the total number of moves each year from their year of birth through age 14 years . mental illness histories , for cohort members as well as their parents and siblings , were obtained from the psychiatric central research register ( mors et  al . , 2011 ) , which was computerized in 1969 and contains data on all admissions to psychiatric inpatient facilities . information on all contacts with psychiatric outpatient and emergency care units has also been captured since 1995 . during years 1969 through 1993 , the diagnostic system used was the danish modification of the international classification of diseases , 8th revision ( world health organization , 1971 ) , and from 1994 , the international classification of diseases , 10th revision , diagnostic criteria for research ( world health organization , 1993 ) . classifications of the psychiatric disorders investigated are shown in etable  1 in the online supplement . onset of each psychiatric disorder was defined as the date of first contact as an inpatient or outpatient , or with psychiatric emergency care . individuals diagnosed with more than one disorder were included in the analysis of each disorder . urbanization of birthplace was classified as central area of the capital city ( copenhagen ) , suburb of the capital , provincial city , provincial town , or rural ( statistics denmark , 1997 ) . information on parental socioeconomic status ( ses ) was obtained from the integrated database for labour market research ( danmarks statistik , 1991 ) , and was derived from paternal and maternal income , highest educational attainment and employment status , measured in the year of cohort members ' 15th birthdays , as reported previously ( webb et  al . , 2015 ) . for each psychiatric disorder examined , cohort members were followed up from their 15th birthday until first treatment of the disorder , death , emigration from denmark , or december 31st 2013 , whichever came first . log - linear poisson regression models were fitted using the sas 9.2 genmod procedure ( sas institute inc . , 2008 ) to estimate incidence rate ratios ( irrs ) . the generic reference category consisted of children who did not move during each age - year of observation . additional adjustments were made for : ( a ) mental disorder in a parent or sibling , urbanicity of place of birth ( pedersen and mortensen , 2001b ) , and parental age at time of the child 's birth ( mcgrath et  al . , 2014 ) ; ( b ) parental ses . age , calendar year , and family psychiatric history were included as time - varying covariates . likelihood ratio - based 95% confidence intervals were calculated for each irr point estimate , and likelihood ratio interaction tests were used to formally assess effect modification by cohort members ' gender . due to the many tests performed , we denote estimates as being statistically significant if p  <  0.003 , approximating a bonferroni correction for multiple testing within each outcome category ( bland and altman , 1995 ) . fig .  1 shows the frequencies of cross - municipality residential change from the year of birth to age 14 years for the study population . residential change occurred most commonly in the one year period after birth and generally became less frequent with increasing age during upbringing . given that the great majority of those who relocated only moved once in a particular year , residential mobility in a given year was categorized as one versus two or more moves in all subsequent analyses . irrs for psychiatric disorders associated with childhood residential change , adjusted for age , sex , calendar year , mental illness in a parent or sibling , parental age , and urbanization of place of birth , are presented in : fig .  2  for ( a ) any substance misuse disorders , ( b ) alcohol misuse , ( c ) cannabis misuse , ( d ) any personality disorders , ( e ) borderline personality disorder , and ( f ) antisocial personality disorder ; fig .  3  for ( a ) broad schizophrenia , ( b ) narrow schizophrenia , ( c ) schizoaffective disorder , ( d ) any mood disorders , ( e ) bipolar disorder , and ( f ) depressive disorder ; fig .  4  for ( a ) any anxiety and somatoform disorders , ( b ) ocd , ( c ) any eating disorders , and ( d ) anorexia nervosa . childhood residential mobility was associated with elevated risks of developing most psychiatric disorders . for any substance misuse disorders , alcohol misuse , cannabis misuse , any personality disorders , borderline personality disorder , broad and narrow schizophrenia , any mood disorders , depressive disorder , and any anxiety and somatoform disorders , relocation at any age from birth to age 14 years was associated with raised risks of developing these disorders . increased risks for antisocial personality disorder although the patterns of association for any mood disorders were less clear , moving two or more times in any one year was in general associated with higher risks of developing these disorders compared with just a single move . for both single and multiple moves , risks tended to rise with increasing age of residential change from around age 9 years . in addition , exceptionally large elevation in risks linked with multiple moves at age 13 and 14 years was observed for any substance misuse disorders , and cannabis misuse in particular , and antisocial personality disorder . the risk of developing a psychiatric disorder associated with each age - year of exposure to multiple moves was also almost consistently higher for antisocial personality disorder than for any other psychiatric diagnostic category examined . residential mobility in the year of birth , and at ages 9 , 10 , and 13 years were associated with significantly raised risks of developing schizoaffective disorders , while for bipolar disorder , heightened risks were linked with moving at ages 2 , 4 , 5 , 7 , 9 , 13 and 14 years , but not at other ages . for ocd , elevated risks were observed for residential changes at ages 13 or 14 years only , while moving homes at any age during development was not linked with heightened risks of developing eating disorders beyond mid - adolescence . irrs adjusted for age , sex , and calendar year only , the most basic level of adjustment , were shown in efigures  13 in the online supplement . comparisons with fig .  2 , fig .  3 , fig . 4 shows that additional adjustments for familial mental illness , parental age and urbanization further attenuated the irrs , as well as narrowing the observed risk differentials between single and multiple moves . the degree of attenuation was particularly appreciable for the three substance misuse disorder categories , the three personality disorder categories , broad and narrow schizophrenia , and schizoaffective disorders . irrs were also similarly attenuated , albeit to a slightly lesser extent , when adjusted for parental ses instead of for familial mental illness , urbanization and parental age . the exceptions were all eating disorders combined and anorexia nervosa specifically , for which ses adjustment did not lead to further attenuation of the irrs compared with basic adjustments . more detailed results are shown in table  1 , in which we compare irrs associated with a residential change at age 14 years for the three types of adjustments , as well as for full adjustments where all potential confounders examined were included . these models showed that 49% of the risk for antisocial personality disorder , and around 40% for each of the three substance misuse disorder categories , associated with a residential change at age 14 years could be explained by familial mental illness , urbanization , parental age and ses . even after adjusting for all potential confounders examined here , residential change at age 14 years was linked with significantly raised risks of developing most psychiatric disorders , with the associations being particularly strong for antisocial personality disorder and cannabis misuse . table  1 also shows whether the associations between residential change at age 14 years and risks of psychiatric disorders differed by gender . using the bonferroni correction to account for multiple significance testing , any personality disorders was the only diagnostic category showing a significant gender interaction , with the associations being stronger for males than for females . in a national cohort of almost 1.5 million people , we found that childhood residential mobility , defined in this study as moves across municipality boundaries , was associated with elevated risks of developing most psychiatric disorders between mid - adolescence and early middle age . the associations generally strengthened with increasing age at moving and were greater for multiple moves in a year compared to a single move , and strengths of association observed varied considerably across the diagnostic categories examined . elevations in risk were particularly marked for antisocial personality disorder , any substance misuse disorders and cannabis misuse in particular , for which higher increases in risks were also observed if relocation occurred during early adolescence . relocation at any age during development was not linked to onset of any eating disorders per se or anorexia nervosa specifically . investigation at age 14 years showed that , with the exception of personality disorders , risks for developing psychiatric illnesses were not modified by gender . to our knowledge , this is the first study investigating the link between childhood residential mobility and the subsequent risk of developing psychopathology across the full spectrum of mental disorders . our findings were generally in line with those reported previously ( brown et  al . , 2012 , dewit , 1998 ) , which showed that frequent childhood geographic relocation was associated with elevated risk of drug misuse in adulthood . unlike dewit ( 1998 ) , however , who reported significant associations with drug misuse primarily amongst males , we found no significant gender interactions with the development of all substance misuse disorders combined and cannabis misuse specifically . also , unlike brown et  al . ( 2012 ) , who reported no elevated risk for anxiety disorders , we found that mobility at any age during development was linked with increased risks for anxiety and somatoform disorders in adulthood . for depressive disorders , ( 2015 ) , who reported that adolescents who moved in the past five years had higher odds of major depressive episode than those who did not . we have additionally shown that increased risks were also linked with residential mobility from birth to age 7 years , and that elevated risks for depression extended into adulthood . ( 2003 ) , who reported a significant association between residential change before age 7 years and onset of depression before age 15 years , but not after . these discrepancies in findings were likely to be at least partly due to the differences in study design and exposure and outcome definitions used . reasons for the observed associations between childhood residential moves and the subsequent development of psychiatric disorders are likely to be complex and variable between families . firstly , increased risk for onset of mental disorders between mid - adolescence and early middle age could be a consequence of serious and enduring difficulties within families , rather than being a direct result of residential mobility . relocation occurs more commonly amongst single parent and step families and those from lower socioeconomic background ( astone and mclanahan , 1994 , susukida et  al . frequent relocation thus could be a marker for familial dysfunction and psychosocial adversity , which are known risk factors for adolescence delinquency and adult psychopathology ( boynton - jarrett et  al . , 2005 , green et  al . , 2010 , kessler et  al . , 2010 ) . however , while we did not examine breakdown of parental relationship , much of the increased risks for psychiatric disorder remained after parental ses was adjusted for , suggesting that the associations between childhood residential change and the subsequent development of mental disorders could not be fully explained by familial socioeconomic disadvantages secondly , related to the first proposed mechanism , individuals with a severe mental illness are more likely than those without a disorder to be residentially mobile ( lix et  al . , the development of psychiatric disorders following residential changes thus could be attributed to intergeneration transmission of psychiatric disorders ( dean et  al . , 2010 , henin et  al . , 2005 , mortensen et  al . , 1999 ) , rather than as a direct consequence of the moves . as in the case of parental ses , adjusting for familial history of mental disorders in our analyses did attenuate the irrs . however , the associations between childhood residential mobility and risk for mental disorder onset in later life persisted , suggesting that the elevated risks observed can not wholly be explained by familial transmission of psychopathology thirdly , families may move because of prodromal symptoms , including problematic behaviors , in older children and early adolescents ( gasper et  al . , this suggests that prior to the residential moves some children might already be showing signs of psychopathology who then subsequently received a formal diagnosis of their disorder . the residential moves per se might or might not have exacerbated these pre - existing disorders . finally , the link between childhood residential move and the subsequent development of psychiatric disorders could indeed be causal . moving home is a source of stress , to parents as well as their children , especially if the latter are not involved in the decision making process . these changes in both neighbourhood and school environments lead to the distruption of routines and social networks , the detrimental impact of which increases as children get older ( herbers et  al . , 2013 , negative behaviors such as drug - taking may provide a quick route via which relocated and marginalised adolescents try to gain acceptance in a new social environment ( dewit , 1998 ) . one of our study 's main strengths was the size of the cohort , which enabled examination of exposure to residential moves during each age - year of upbringing , as well as gender - specific associations . by using a prospective design and national registry data , our study was free of recall and attrition biases , which would be particularly salient if residential moves occurred frequently and if the follow - up period was long . by including only individuals with danish - born parents , we effectively controlled for increased risk of psychiatric disorder linked with inter - country migration ( cantor - graae and pedersen , 2013 ) . the most significant limitation of our study is that we do not know the context of residential changes and , although we controlled for a number of potential confounders , others such as parental separation were not investigated . however , tseliou et  al . ( 2015 ) reported that parental relationship breakup did not modify the link between childhood residential change and poor mental health ten years on , suggesting that some of the links that we observed may be causal . in addition , most people who experience mental disorders with milder symptoms are not treated for these disorders in psychiatric units , and so many of these cases will not have been recorded in the psychiatric central research register . hence , only cases of psychiatric disorders with a higher degree of severity treated in secondary care settings were investigated in our study . persons with eating disorders or ocd without comorbidity are also likely to be treated in outpatient rather than inpatient settings . since information on outpatients was not available until 1995 , we may not have captured some cases of these disorders for those born earlier in our cohort . however , the same may also be said for personality disorders , for which particularly strong associations with residential moves were observed . thus , if outpatient information was available for earlier periods , we may have observed even larger effect sizes for personality disorders . furthermore , as our study cohort includes those who were born between 1971 and 1997 , and parental ses data were only available from 1981 onwards , we were unable to adjust for parental ses from the time of each cohort member 's birth . parental ses was instead measured at a fixed time - point , in the year of start of follow - up when cohort members turned age 15 years . our study indicates that childhood residential mobility is associated with increased risks of developing a broad array of psychiatric disorders on reaching maturity . the greatest elevation in risk was found in behavior - related disorders  antisocial personality disorder and cannabis misuse . community and mental health services , as well as schools and colleges , need to be vigilant of the psychosocial needs of children , particularly adolescents , who have recently moved homes . further research is warranted to explore the mechanisms that explain these observed links between childhood residential relocation and the subsequent onset of psychiatric illness .
although links between childhood residential mobility and subsequently increased risks of psychopathology have been well documented , associations across the full spectrum of psychiatric disorders are unknown . we conducted a population - based study of all 1,439,363 persons born in denmark during 19711997 to investigate relationships between childhood cross - municipality residential moves from year of birth to age 14 years and the development of a range of psychiatric disorders from mid - adolescence to early middle age . 
 we examined : ( 1 ) any substance misuse disorders ; specifically alcohol misuse , and cannabis misuse ; ( 2 ) any personality disorders ; specifically antisocial , and borderline personality disorders ; ( 3 ) schizophrenia and related disorders ; specifically schizophrenia , and schizoaffective disorder ; ( 4 ) any mood disorders ; specifically bipolar disorder , and depressive disorder ; ( 5 ) any anxiety and somatoform disorders ; specifically obsessive compulsive disorder ; ( 6 ) any eating disorders ; specifically anorexia nervosa . 
 childhood residential mobility was associated with elevated risks of developing most psychiatric disorders , even after controlling for potential confounders . 
 the associations generally rose with increasing age at moving and were stronger for multiple moves in a year compared to a single move . 
 links were particularly strong for antisocial personality disorder , any substance misuse disorder , and cannabis misuse in particular , for which the highest increases in risks were observed if relocation occurred during adolescence . 
 childhood residential change was not linked to subsequent risk of developing an eating disorder . 
 frequent residential mobility could be a marker for familial adversities . 
 mental health services and schools need to be vigilant of the psychosocial needs of children , particularly adolescents , who have recently moved homes .