R E G U L A R A R T I C L E
Psychiatric morbidity in two low birth weight groups assessed by diagnostic
interview in young adulthood
Line K Lund ([email protected])1,2, Torstein Vik3, Jon Skranes3,4, Ann-Mari Brubakk3,4, Marit S Indredavik1,2
1.Department of Neuroscience, Children’s and Women’s Health, Norwegian University of Science and Technology, Trondheim, Norway 2.Department of Child and Adolescent Psychiatry, St. Olav’s University Hospital, Norway
3.Department of Laboratory Medicine, Children’s and Women’s Health, Norwegian University of Science and Technology, Trondheim, Norway 4.Department of Pediatrics, St. Olav’s University Hospital, Norway
Keywords
Adult outcomes, Behavioural problems, Birth weight, Gestational age, Mental health
Correspondence
Line K Lund, RBUP, Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, NO-7489 Trondheim, Norway. Tel: +47 73 55 15 58 |
Fax: +47 73 55 15 39 | Email: [email protected] Received
4 August 2010; revised 20 October 2010; accepted 29 November 2010.
DOI:10.1111/j.1651-2227.2010.02111.x
ABSTRACT
Aim: To study the prevalence and characteristics of psychiatric symptoms and disorders in young adults born with low birth weight.
Methods: At 20 years of age 44 very low birth weight (VLBW: birth weight £1500 g), 55 term born small for gestational age (SGA: birth weight <10th percentile) and 75 control subjects born 1986–1988 were assessed using the interview Schedule for Affective Disorders and Schizophrenia for School-age children and Structured Clinical Inter-view for DSM-IV Personality Disorders, Children’s Global Assessment Scale and Attention deficit hyperactivity disorder (ADHD) Rating Scale IV; self-report and parent report.
Results: Fourteen (33%) VLBW versus six (8%) control participants had a definite psychiatric disorder: OR = 5.6 (1.9–15.9). In the term SGA group, 14 (26%) had a disor-der: OR = 3.9 (1.4–11.0) vs controls. Anxiety disorders and ADHD were the most frequent diagnoses. The differences were not explained by gender, assessment age or parental socioeconomic status. ADHD Rating Scale mean scores were higher in parent reports in the VLBW group and in self-reports in the term SGA group compared with the control group.
Conclusion: Children born with low birth weight whether caused by preterm birth or by growth retardation at term seem to be at increased risk for psychiatric disorders as young adults.
INTRODUCTION
In the last decades, an increasing number of very preterm born children have survived, mainly because of continuous improvements in obstetric and neonatal care. The long-term sequelae for survivors after preterm birth include cerebral palsy, mental retardation and other cognitive dysfunction, sensory impairment and respiratory illness (1). The neuro-behavioural impairments seem to persist into adolescence and young adulthood (2). Furthermore, increased psychiat-ric morbidity has been reported, including symptoms of attention deficit hyperactivity disorder (ADHD), depression and anxiety (3–6), as well as increased risk for being
hospitalized for psychiatric problems in adolescence and young adulthood (7).
To be born small for gestational age (SGA) at term may suggest intrauterine growth restriction and involves an increased risk for reduced cognitive capacity and academic achievement in young adulthood (8). Behavioural problems in adolescence have also been reported (9,10). According to a Swedish population–based registry study, being born SGA at term was associated with later psychiatric hospitalization (11). In a Norwegian population, increased risk for adult anxiety and depression was found (12); however, no increased lifetime risk of major depression was reported in the New England Family study (13).
Previous studies on late effects of low birth weight in young adulthood have mainly been based on questionnaires or medical registers, while to our knowledge only few have used psychiatric interviews for diagnostic assessment (4,13). The aim of the present study was to investigate the preva-lence and characteristics of psychiatric disorders and symp-toms in 20-year-old men and women born preterm with VLBW or term SGA compared with controls, using psychi-atric interview and questionnaires. We hypothesized that preterm VLBW and term SGA young adults had higher prevalence of psychiatric symptoms and disorders com-pared with their normal birth weight peers.
Abbreviations
ADHD, Attention deficit hyperactivity disorder; ANOVA, Analy-sis of variance; CGAS, Children’s global assessment scale; CI, Confidence interval; CP, Cerebral palsy; DSM-IV, Diagnostic and statistical manual of mental disorders; GA, Gestational age; K- SADS, Schedule for affective disorder and schizophrenia for school-age children; OR, Odds ratio; SCID 2, Structured clinical interview for DSM-IV personality disorders; SES, Socioeconomic status; SGA, Small for gestational age; VLBW, Very low birth weight.
PARTICIPANTS AND METHODS Study design
This is a population-based follow-up study of two groups of young adults born with low birth weight and a control group all born between 1986 and 1988. One group com-prised participants born preterm with very low birth weight (VLBW) defined by a birth weight £1500 g. The other low birth weight group comprised participants born SGA at term, defined by a birth weight below the 10th per-centile adjusted for gestational age (GA), gender and parity (14). The control subjects were born at term with birth weight ‡10th percentile for GA, adjusted for gender and parity.
The participants in the VLBW group had been admitted to the neonatal intensive care unit at The University Hospi-tal in Trondheim, Norway, which is the referral centre for VLBW newborns in the counties of North and South Trøndelag, thus covering a complete population-based birth cohort.
The SGA and control participants were enrolled as part of a multicentre study in Uppsala, Sweden, and in Trond-heim and Bergen, Norway (14). A 10% random sample of women was selected for follow-up during pregnancy. At birth, all children of mothers in the random sample and all children born SGA in the nonrandom sample were included for follow-up. In the present study only participants enrolled in Trondheim were included.
We have previously studied mental health problems in the same population of preterm VLBW and term SGA ado-lescents at 14 years of age using diagnostic interview and questionnaires (3,9). The present study was carried out between 2006 and 2008.
Study population The preterm VLBW group
A total of 99 children were admitted to the Neonatal Inten-sive Care Unit in Trondheim during the enrolment period. Of these, 23 died and one with a congenital syndrome was excluded. In addition, two with severe CP and ⁄ or mental retardation were excluded at follow- up. Of the remaining 73, 14 had moved or could not be traced and 59 were invited to participate. Of these, 15 did not consent, leaving 44 young adults (17 men and 27 women) available for fur-ther study (75% of invited and 60% of eligible). Twelve (27%) of these VLBW subjects were born SGA (VLBW-SGA). The reference standards for classification of SGA (below 10th percentile) were gender-specific for each gesta-tional week based on data from the Norwegian Medical Birth Registry (15).
The term SGA group
Among the 1200 eligible women in the Trondheim part of the multicenter study, 104 (9%) gave birth to an SGA child at term. One newborn with a congenital syndrome was excluded. Of the remaining 103 eligible participants, 17 had moved or could not be traced. Hence, 86 were invited, of whom 31 did not consent. Thus, 55 subjects (24 men and 31 women) participated (64% of invited and 53% of eligible).
The control group
The control group was recruited from the random sample and included 120 subjects, of whom two with congenital syndrome were excluded. Of the remaining 118, 16 had moved or could not be traced. Hence, 102 subjects were invited, of whom 27 did not consent. Thus, 75 subjects (32 men and 43 women) participated (74% of invited and 64% of eligible).
Nonparticipants
There were no statistically significant differences in birth weight, gestational age and head circumference at birth between participants and those who did not consent to par-ticipate in any of the three study groups (data not shown). In the VLBW group, the proportion of men was higher among those who declined to participate compared to those who participated (data not shown, p = 0.007).
Methods
Psychiatric disorders and symptoms were evaluated by interviewing the young adults using Schedule for Affective Disorder and Schizophrenia for School-age children, Pres-ent and Life time version (K-SADS-PL) (16). This is a semi-structured psychiatric interview consisting of one screening part and supplementary interviews constructed to assess psychiatric symptoms and diagnoses according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (17). In K-SADS, diagnoses are scored as defi-nite, probable (i.e. subthreshold); ‡75% level of symptom criteria met or not present. Definite disorders as well as the sum of subthreshold and definite disorders are used as outcome categories in this study, the latter denoted ‘sub-threshold ⁄ definite’ disorders. K-SADS was supplemented with screening of the DSM-IV general diagnostic criteria for personality disorders, and if indicated, the Structured Clinical Interview for DSM-IV Personality Disorders (SCID-II) (18). All participants were interviewed by the same trained physician, and a senior child and adolescent psychiatrist was consulted before final diagnostic decision. Both were blinded to birth weight status. Interview was performed with 43 VLBW (one missing), 55 SGA and 75 control participants. Those who had psychiatric diagnoses were offered a referral for treatment.
Overall social and psychiatric function was scored by the interviewer according to Children’s Global Assessment Scale (CGAS) (19). CGAS ranges from 0 to 100; scores £70 indicate reduced function, scores between 71 and 80 denote slight impairment and scores >80 indicate good psychoso-cial functioning.
We supplemented the psychiatric interview with the ADHD Rating Scale IV, Adult Self Report and Home Version (parent report) (20,21). The ADHD Rating Scale comprises 18 items constituting two subscales; one for inattentive and one for hyperactive ⁄ impulsive problems. We obtained self-reports from 43 VLBW, 55 SGA and 74 controls and parent reports from 28 VLBW, 34 SGA and 46 controls.
The parents’ socioeconomic status (SES) was calculated according to Hollingshead’s two factor index of social
position (22) based on data collected at the 14-year assess-ment. Reports were supplemented with data at 20 years of age if available and were completed for 42 VLBW, 47 SGA and 68 control participants.
Ethics
The Regional Committee for Medical and Health Research Ethics in Central Norway approved the study protocol (Pro-ject number: 4.2005.2605). Participation was based on writ-ten informed consent.
Statistical analysis
SPSS for Windows version 17.0 (SPSS Inc. Chicago, IL, USA) was used for data analysis. A two-sided p-value <0.05 was considered statistically significant. Comparisons between three groups were performed using ANOVA for normally distributed data and Kruskall–Wallis test for ordinal ⁄ not normally distributed data with Bonferroni or Mann–Whitney U-test for post hoc testing. We used Chi-squared tests for comparison of proportions, alternatively Fisher exact test when appropriate. Logistic regression anal-ysis was used to calculate the odds ratios (ORs) with 95% Confidence Intervals (CIs) that a person in a low birth weight group would have definite psychiatric diagnoses or subthreshold ⁄ definite diagnoses, with the control group as a reference. We adjusted for potential confounders separately to avoid model over fitting (23).
On the ADHD rating scale self-report and parent report, all items were complete in most cases (166 ⁄ 173 self-reports and 104 ⁄ 108 parent reports). Single missing items were handled by simple mean imputation.
RESULTS
Group characteristics
Participant characteristics are shown in Table 1. Parental SES did not differ between groups. Three participants had
cerebral palsy, two in the VLBW group (both bilateral spas-tic subtype, one of these with four limb affection) and one in the SGA group (spastic bilateral subtype). In the VLBW group, 11 were born as twins, of whom six were in twin pairs. Within the VLBW group, 32 were born appropriate for ges-tational age (non-SGA) with mean GA (weeks): 27.9 (SD: 1.6) and mean birth weight (g): 1216 (SD: 199), while 12 were born VLBW-SGA with mean GA: 31.9 (SD: 1.9, p < 0.01 versus non-SGA group) and mean birth weight (g): 1290 (SD: 220, ns versus non-SGA group), three of these were born as twins. Mean SES was 3.4 in the non-SGA group versus 2.8 in the VLBW-SGA group (p = 0.2). Eleven partic-ipants (25%) in the VLBW group, 10 (18%) in the SGA group and 10 (13%) in the control group reported to have ever been treated for psychological ⁄ psychiatric problems.
Psychiatric assessment in the preterm VLBW group Fourteen (33%) participants in the VLBW group compared with six (8%) in the control group had a definite psychiatric disorder (p = 0.001) and 20 (47%) VLBW subjects com-pared with 15 (20%) control subjects had a subthresh-old ⁄ definite disorder (p = 0.003) (Table 2). Anxiety disorders and ADHD were the most frequent diagnoses. Five VLBW participants and one in the control group had more than one diagnosis (p = 0.02). Comorbid disorders were anxiety disorders, ADHD, depression, eating disorder, conduct disorder and alcohol and ⁄ or substance abuse.
The VLBW subjects had higher odds ratios (ORs) for any definite psychiatric diagnosis (5.6 (CI: 1.9–15.9) and any subthreshold ⁄ definite diagnosis (3.5 (CI: 1.5–7.9) than con-trols (Table 3). After adjusting for gender, assessment age and parental SES, the odds ratios for definite and sub-threshold ⁄ definite disorders were still increased, although parental SES reduced the ORs by more than 20%.
The mean CGAS score: 76 (SD: 14) was lower in VLBW young adults than in the control group: 86 (SD: 8, p < 0.001). The scores on the ADHD Rating Scale did not
Table 1 Family characteristics and characteristics of the young adults in two groups of low birth weight young adults and a control group at 20 years of age
VLBW (n = 44) SGA (n = 55) Control (n = 75)
n Mean (SD) n Mean (SD) n Mean (SD)
Family characteristics
Parental socioeconomic status† 42 3.3 (1.4) 47 3.5 (1.2) 68 3.6 (1.0)
Young adult characteristics
Birth weight (grams) 44 1236 (205)* 55 2911 (240)* 75 3716 (473)
Gestational age (weeks) 44 29.0 (2.5)* 55 39.6 (1.2) 75 39.8 (1.2)
Assessment age (years) 44 19.5 (0. 6) 55 19.8 (0. 7) 75 19.7 (0. 5)
n (%) n (%) n (%)
N (gender ratio male: female) 17:27 (39:61) 24:31 (44:56) 32:43 (43:57)
Cerebral Palsy‡ 2 (5) 1 (2) 0 (0)
In psychological treatment§ 3 (7) 5 (9) 2 (3)
Three group comparisons were made by ANOVA and Bonferroni post hoc test. *p £ 0.001 vs. controls.
†Parental socioeconomic status according to Hollingshead’s two factor index of social position. ‡Cerebral palsy: two with spastic diplegia and one with tetraplegia.
§In psychological treatment at the time of the interview.
differ from the control group when reported by the partici-pants themselves (data not shown). Parents of VLBW young adults reported higher inattention (Mean (SD); 5.5 (5.6) vs 2.0 (2.5), p = 0.004) and total scores (8.1 (8.8) vs 3.4 (4.2), p = 0.01) but not higher hyperactivity scores in their off-spring compared with control parents.
When we stratified the results from interview and CGAS according to gender, the differences between the VLBW and the control group were essentially the same for men and women (data not shown).
In the VLBW-SGA subgroup, 7 of 12 (58%) participants had a definite psychiatric disorder compared with 7 of 31 (23%) subjects in the VLBW non-SGA subgroup (p = 0.04). Mean CGAS was 68 (SD: 16) in the VLBW-SGA subgroup versus 79 (SD: 11) in the non-SGA subgroup (p = 0.04).
Psychiatric assessment in the term SGA group
Fourteen (26%) SGA subjects had a definite psychiatric dis-order (p = 0.006 versus controls) while 26 (47%) had a sub-threshold ⁄ definite disorder (p = 0.001 versus controls) (Table 2). Anxiety disorders were the most frequent diagno-ses followed by ADHD. Three SGA subjects had comorbid disorders and these were ADHD, anxiety disorders, Tourette’s disorder and conduct disorder.
Using the control group as a reference, the OR for any definite psychiatric diagnosis was 3.9 (CI:1.4–11.0) and for any subthreshold ⁄ definite diagnosis: 3.6 (CI:1.7–7.8) (Table 3). After adjusting for gender, assessment age and parental SES, the SGA group still had higher ORs for any definite and subthreshold ⁄ definite disorder compared with controls.
The mean CGAS score (78; SD: 13) of the SGA group was significantly lower than in the control group
Table 2 Psychiatric morbidity according to diagnostic and statistical manual of mental disorders in two groups of low birth weight young adults and a control group at 20 years of age
VLBW (n = 43) SGA (n = 55) Control (n = 75)
n (%) n (%) n (%)
Definite psychiatric disorders
Any 14 (33)*** 14 (26)** 6 (8) Of these Anxiety disorders† 8 (19)** 7 (13)* 2 (3) ADHD 6 (14)** 4 (7)* 0 (0) Mood disorders‡ 2 (5) 3 (6) 2 (3) Other§ 3 (7) 4 (7) 2 (3)
More than one diagnosis 5 (12)** 3 (6) 0 (0) Sum of subthreshold and definite disorders¶
Any 20 (47)** 26 (47)*** 15 (20) Of these Anxiety disorder 12 (28)** 12 (22)* 6 (8) ADHD 7 (16) 8 (15) 4 (5) Mood disorders 4 (9) 5 (9) 3 (4) Other 8 (19) 12 (22)* 7 (9)
Chi-square test with Fisher exact when expected cell number <5. *p < 0.05, **p < 0.01, ***p £ 0.001 vs. controls.
†Anxiety disorders were phobia, obsessive compulsive disorder, post-traumatic
stress disorder and generalized anxiety disorder.
‡Mood disorders were major depressive disorder, bipolar disorders, dysthymic
disorder and depressive disorder NOS.
§Other disorders were Tourette’s disorder, eating disorder NOS, adjustment
disorders, oppositional defiant disorder, conduct disorder, alcohol and illicit drug abuse and addiction.
¶Includes both subthreshold diagnoses (‡75% level of diagnostic criteria met)
and definite diagnoses.
VLBW = Very low birth weight; SGA = Small for gestational age; ADHD = Attention deficit hyperactivity disorder.
Table 3 Odds ratios for psychiatric morbidity in two groups of low birth weight with controls as reference group at the mean age of 20, unadjusted and after separate adjustments for gender, assessment age and parental socioeconomic status
Psychiatric diagnosis* Sum of subthreshold and definite disorders†
OR (95% CI) p OR (95% CI) p
Unadjusted (N = 173)
VLBW 5.6 (1.9–15.9) 0.001 3.5 (1.5–7.9) 0.003
SGA 3.9 (1.4–11.0) 0.009 3.6 (1.7–7.8) 0.001
Control (reference group) 1 1
Adjusted for gender (n = 173)
VLBW 5.8 (2.0–17.0) 0.001 3.5 (1.5–8.1) 0.003
SGA 4.2 (1.5–12.1) 0.008 3.8 (1.7–8.3) 0.001
Control (reference group) 1 1
Adjusted for assessment age (n = 173)
VLBW 5.6 (1.9–16.2) 0.001 3.5 (1.5–8.1) 0.003
SGA 3.9 (1.4–11.0) 0.01 3.6 (1.7–7.8) 0.001
Control (reference group) 1 1
Adjusted for socioeconomic status (n = 156)
VLBW 4.2 (1.4–12.4) 0.01 2.7 (1.1–6.4) 0.03
SGA 3.1 (1.0–9.2) 0.04 3.2 (1.4–7.4) 0.008
Control (reference group) 1 1
*Any psychiatric diagnosis.
†Includes both subthreshold diagnoses (‡75% level of diagnostic criteria met) and definite diagnoses.
(p < 0.001). On the ADHD Rating Scale, the SGA young adults reported higher mean scores than controls on inat-tention (Mean (SD): 5.6 (3.8) vs 4.0 (3.7), p = 0.008), hyper-activity (6.0 (3.8) vs 4.2 (3.2), p = 0.004: and total scores (11.5 (6.9) vs 8.2 (6.2), p = 0.002), while reports from par-ents did not differ between the two groups (data not shown).
When we stratified the analyses according to gender, the results regarding definite diagnoses, subthreshold ⁄ definite diagnoses and CGAS scores were essentially the same for men and women (data not shown), with the exception that the frequency of diagnoses was only borderline significant between SGA and control women (p = 0.06).
DISCUSSION
In this study, young adults born with VLBW had higher prevalence of psychiatric disorders than controls. Thus, we have confirmed and extended our previous finding of increased risk for psychiatric problems in this group, dem-onstrating that the higher risk is still present in young adult-hood. The new finding was the high prevalence of psychiatric disorders in adults born SGA at term.
The strength of the study is the inclusion of in-depth psy-chiatric interview allowing for diagnostic assessment according to DSM-IV criteria. All interviews were per-formed by the same trained physician. The use of semi-structured interviews makes it possible to add questions to clarify inconsistent responses. This may increase the validity of our findings compared with studies relying only on ques-tionnaires. We wanted to use the same instruments as in the 14-year assessment if reasonable. Kiddie-SADS-PL has been applied to populations in young adulthood (24), and in addition, we used the SCID-II on personality disorders if indicated. A global assessment scale (CGAS) was used to supplement the diagnostic interview by combining social and psychiatric functioning into a unidimensional index of severity. Although designed for children up to 16 years of age, CGAS was originally derived from the adult Global Assessment Scale (GAS) and has formerly been applied in young adult age (25).
The differences between the two low birth weight groups and the control group were generally large as indicated by the low p-values and therefore unlikely to be due to chance. However, the relatively low sample size limits the generaliz-ability of the study and negative findings should be inter-preted with caution. Furthermore, the small sample size made this study unsuited for detecting disorders with low frequency (i.e. more severe psychiatric disorders).
Small for gestational age is a crude measure of intrauter-ine growth restriction. Some children born at term with a birth weight below the 10th percentile are genetically nor-mal snor-mall children, while those with higher birth weights may be significantly growth restricted. Such misclassifica-tion may have diluted actual differences.
The interviewer was blinded to birth weight category, mak-ing information bias unlikely. There were no differences in perinatal key variables between dropouts and participants.
More men than women in the VLBW group chose not to participate. Despite this selection bias, the results were mainly unchanged when analysed separately for men and women.
Our results were not confounded by age or gender. Paren-tal SES was a confounder of the observed differences as SES changed the odds ratios for definite psychiatric disor-ders and subthreshold ⁄ definite disordisor-ders in both groups with low birth weight; however, the main results persisted after adjustment.
In the present study, the strength of association was high in both low birth weight groups and this may suggest a cause–effect relationship between low birth weight and mental disorders. What leads to a psychiatric disorder is complex and involves both individual and social factors. Children born preterm with VLBW may have neurological sequela associated with perinatal injury (1), and cerebral MRI abnormalities may persist into adulthood (26). Hence, a plausible biological mechanism is that perinatal brain injury affects later mental health, although possibly modi-fied by psychosocial factors. Such an explanation is particu-larly likely in the VLBW group.
Furthermore, there is rising evidence that gene expression may be influenced by environmental factors through com-plex epigenetic mechanisms (27), and this has also been found within research on mental health. Low birth weight, as an effect of restricted nutrients in utero may, according to the Barker hypothesis (28), change the physiology and metabolism of the foetus. These changes may serve as risk factors for later chronic disease in both children born pre-term with VLBW and children born SGA at pre-term.
Common mental disorders have been shown to be more frequent in populations with less privileged social position (29). Intrauterine growth restriction may be caused by mul-tiple factors and is also associated with low socioeconomic status (30). Low SES is furthermore associated with mater-nal use of tobacco, alcohol and drugs during pregnancy and these factors may in turn result in intrauterine growth restriction (31). An interaction effect of being born with low birth weight and raised under socially disadvantaged cir-cumstances in respect to adverse long-term effect on mental health problems has been suggested (32). Intrauterine growth restriction and low SES may therefore be interre-lated risk factors for later common mental disorders. These complex mechanisms may contribute to the high prevalence of psychiatric problems in the term SGA group.
Our finding of frequent psychiatric disorders and symp-toms including the high prevalence of anxiety disorders among VLBW young adults is consistent with previous research (4,5,7). However, in contrast to Walshe et al., we did not find more mood disorders among the VLBW partici-pants, which is in agreement with our assessment at 14 years of age. A significant proportion of the participants had more than one diagnosis, emphasizing wide-ranging problems.
Intrauterine growth restriction in addition to preterm birth has been shown to increase the risk for symptoms of ADHD among young adults born with VLBW (33). Despite
the higher mean GA, psychiatric diagnoses were more frequent in our subgroup born VLBW-SGA than in the non-SGA subgroup. This finding, in addition to the high prevalence of psychiatric disorders in the group born SGA at term, supports the hypothesis that restricted intrauterine growth may play an additive role in the causal chain leading to mental health problems.
In contrast to the emerging studies on mental health in adult subjects born VLBW, we have only found few earlier studies addressing mental health in young adults born SGA at term (11–13). The frequency of psychiatric disorders and symptoms in our study was higher than found in former studies, possibly because of different designs and ⁄ or methods.
Clinical implications and future research
Young adulthood is a phase of transition with an accu-mulation of stress factors involved in the process of establishing an independent adult life. Subgroups might be differentially sensitive to how stress is experienced, and we speculate that low birth weight individuals may be more vulnerable to stressful challenges during this transitional stage.
Mental health problems may and may not persist over time, and further research is warranted to see how these groups cope with their adult life and how they evaluate their own health status in the future.
Persons born SGA at term make up a larger group in soci-ety than preterm VLBW subjects; hence, medical problems have a potentially large influence on public health. There-fore, it is essential to include term born SGA as well as pre-term born children in further research on late effects of low and subnormal birth weight. Special attention should be given to the mental health of individuals born both preterm and SGA.
CONCLUSION
In this study, one of three born with VLBW and one of four born SGA at term had psychiatric disorders in young adult-hood. The psychiatric morbidity was significantly higher than in a control group born at term with normal birth weight. The most frequent diagnoses were anxiety disorders and ADHD. The subgroup born both preterm and SGA seemed to be particularly vulnerable.
ACKNOWLEDGEMENTS
We thank the young adults and their parents for their co-operation and interest in the study. We also thank Inger Johanne Bakken, PhD Senior consultant, The Norwegian Patient Register Norwegian Directorate of Health for her assistance in statistics.
FINANCIAL SUPPORT
The study was funded by The Research Council of Norway, Norwegian University of Science and Technology and
Liaison Committee between the Central Norway Regional Health Authority (RHA) and the Norwegian University of Science and Technology (NTNU). Part of the study popula-tion was recruited from a multicenter study sponsored by the US National Institute of Child Health and Human Development, NIH (NICHD contract No. 1-HD-4-2803 and No. 1-HD-1-3127).
DISCLOSURE
The authors report no conflicts of interest.
References
1. Saigal S, Doyle LW. An overview of mortality and sequelae of preterm birth from infancy to adulthood. Lancet 2008; 371: 261–9.
2. Aarnoudse-Moens CS, Weisglas-Kuperus N, van Goudoever JB, Oosterlaan J. Meta-analysis of neurobehavioral outcomes in very preterm and ⁄ or very low birth weight children. Pediatrics 2009; 124: 717–28.
3. Indredavik MS, Vik T, Heyerdahl S, Kulseng S, Fayers P, Bru-bakk AM. Psychiatric symptoms and disorders in adolescents with low birth weight. Arch Dis Child Fetal Neonatal Ed 2004; 89: F445–50.
4. Walshe M, Rifkin L, Rooney M, Healy E, Nosarti C, Wyatt J, et al. Psychiatric disorder in young adults born very preterm: role of family history. Eur Psychiatry 2008; 23: 527–31.
5. Hack M, Youngstrom EA, Cartar L, Schluchter M, Taylor HG, Flannery D, et al. Behavioral outcomes and evidence of psy-chopathology among very low birth weight infants at age 20 years. Pediatrics 2004; 114: 932–40.
6. Johnson S, Hollis C, Kochhar P, Hennessy E, Wolke D, Marlow N. Psychiatric disorders in extremely preterm children: longitu-dinal finding at age 11 years in the EPICure study. J Am Acad Child Adolesc Psychiatry2010; 49: 453–63e1.
7. Lindstrom K, Lindblad F, Hjern A. Psychiatric morbidity in adolescents and young adults born preterm: a Swedish national cohort study. Pediatrics 2009; 123: e47–53.
8. Strauss RS. Adult functional outcome of those born small for gestational age: twenty-six-year follow-up of the 1970 British birth cohort. JAMA 2000; 283: 625–32.
9. Indredavik MS, Vik T, Heyerdahl S, Kulseng S, Brubakk AM. Psychiatric symptoms in low birth weight adolescents, assessed by screening questionnaires. Eur Child Adolesc Psychiatry 2005; 14: 226–36.
10. O’Keeffe MJ, O’Callaghan M, Williams GM, Najman JM, Bor W. Learning, cognitive, and attentional problems in adoles-cents born small for gestational age. Pediatrics 2003; 112: 301–7.
11. Monfils Gustafsson W, Josefsson A, Ekholm Selling K, Sydsjo G. Preterm birth or foetal growth impairment and psychiatric hospitalization in adolescence and early adulthood in a Swedish population-based birth cohort. Acta Psychiatr Scand 2009; 119: 54–61.
12. Berle JØ, Mykletun A, Daltveit AK, Rasmussen S, Dahl AA. Outcomes in adulthood for children with foetal growth retarda-tion. A linkage study from the Nord-Tro¨ndelag Health Study (HUNT) and the Medical Birth Registry of Norway. Acta Psy-chiatr Scand2006; 113: 501–9.
13. Vasiliadis HM, Gilman SE, Buka SL. Fetal growth restriction and the development of major depression. Acta Psychiatr Scand2008; 117: 306–12.
14. Vik T, Markestad T, Ahlsten G, Gebre-Medhin M, Jacobsen G, Hoffman H, et al. Body proportions and early neonatal mor-bidity in small-for-gestational-age infants of successive births. Acta Obstet Gynecol Scand Suppl1997; 165: 76–81.
15. Skjaerven R, Gjessing HK, Bakketeig LS. Birthweight by gesta-tional age in Norway. Acta Obstet Gynecol Scand 2000; 79: 440–9.
16. Kaufman J, Birmaher B, Brent D, Rao U, Flynn C, Moreci P, et al. Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL): initial reliability and validity data. J Am Acad Child Ado-lesc Psychiatry1997; 36: 980–8.
17. Diagnostic and statistical manual of mental disorders, 4th Edn, Text Revision ed. Washington, DC: American Psychiatric Association; 2000.
18. First MB, Gibbon MSW, Spitzer RL, Williams JBW, Benjamin LS. User’s guide for the structured clinical interview for DSM-IV axis II personality disorders (SCID-II). Washington, DC: American Psychiatric Press, 1997.
19. Shaffer D, Gould MS, Brasic J, Ambrosini P, Fisher P, Bird H, et al. A children’s global assessment scale (CGAS). Arch Gen Psychiatry1983; 40: 1228–31.
20. Barkley RA, Murphy KR. Attention deficit hyperactivity disor-der- A clinical workbook. New York: Guilford Press, 1998. 21. Kvilhaug G, Høigaard B, Rønhovde T, Aase H, Eilertsen O,
Rydin SA, et al. AD ⁄ HD: et verktøy for kartlegging av barn og ungdom. Oslo: Novus, 1998.
22. Hollingshead A. Two factor index of social position. New Haven: Connecticut, 1957.
23. Vittinghoff E, McCulloch CE. Relaxing the rule of ten events per variable in logistic and cox regression. Am J Epidemiol 2007; 165: 710–8.
24. Miller CJ, Miller SR, Newcorn JH, Halperin JM. Personality characteristics associated with persistent ADHD in late adoles-cence. J Abnorm Child Psychol 2008; 36: 165–73.
25. Weissman MM, Warner V, Fendrich M. Applying impairment criteria to children’s psychiatric diagnosis. J Am Acad Child Adolesc Psychiatry1990; 29: 789–95.
26. Allin M, Henderson M, Suckling J, Nosarti C, Rushe T, Fearon P, et al. Effects of very low birthweight on brain structure in adulthood. Dev Med Child Neurol 2004; 46: 46–53. 27. Rutter M, Moffitt TE, Caspi A. Gene-environment interplay
and psychopathology: multiple varieties but real effects. J Child Psychol Psychiatry2006; 47: 226–61.
28. Barker DJ. The wellcome foundation lecture, 1994. The fetal origins of adult disease. Proc Biol Sci 1995; 262: 37–43. 29. Fryers T, Melzer D, Jenkins R. Social inequalities and the
com-mon mental disorders: a systematic review of the evidence. Soc Psychiatry Psychiatr Epidemiol2003; 38: 229–37. 30. Hendrix N, Berghella V. Non-placental causes of intrauterine
growth restriction. Semin Perinatol 2008; 32: 161–5. 31. Wakschlag LS, Pickett KE, Kasza KE, Loeber R. Is prenatal
smoking associated with a developmental pattern of conduct problems in young boys? J Am Acad Child Adolesc Psychiatry 2006; 45: 461–7.
32. Bohnert KM, Breslau N. Stability of psychiatric outcomes of low birth weight: a longitudinal investigation. Arch Gen Psy-chiatry2008; 65: 1080–6.
33. Strang-Karlsson S, Raikkonen K, Pesonen AK, Kajantie E, Paavonen EJ, Lahti J, et al. Very low birth weight and
behavioral symptoms of attention deficit hyperactivity disorder in young adulthood: the Helsinki study of very-low-birth-weight adults. Am J Psychiatry 2008; 165: 1345–53.