Attention deficit hyperactivity disorder (ADHD) and conduct disorder in children of drug dependent parents.

BACKGROUND: Attention deficit hyperactivity disorder and conduct disorder are amongrelatively prevalent disorders during childhood and adolescence.Considering the negative impact of the parents' drug dependency andbipolar disorder, the present study aimed to determine the prevalence ofADHD and conduct disorder in children of drug-dependent and bipolar parents.
METHODS: In this case-control study, the case group included two groups ofpatients with drug dependency and bipolar disorder hospitalized inShahid Beheshti hospital in Kerman who had 7 to 11-year-old children.The control group included healthy individuals without any drugdependency or other psychiatric disorders. Data were collected usingRutter scale Form A (parents' form) and a demographic questionnaire.Data were analyzed with ANOVA, Chi-square and Tamhane's post-hoc test.
FINDINGS: Rutter's abnormal scores were generally 7.11% in children of drugdependent parents, 14% in children of bipolar parents and 1.6% in childrenof healthy parents demonstrating no significant difference. The frequencyof conduct disorder in the bipolar and drug dependent group was higherthan the healthy group, but the difference was not significant. Thefrequency of ADHD was 8.9% in the drug dependency group and 1% inthe control group which shows a significant difference.
CONCLUSION: Drug dependency in parents may be a leading factor to mentaldisorders such as ADHD and conduct disorder in children.

Introduction

ADHD is a sustainable pattern of inattention ,hyperactivity and impulsed behavior, which can have harmful consequences for the patients' social life. It was called childhood hyper-kinetic reaction before. It is estimated that 3 to 5 percent of children show the symptoms in primary school.1

In addition to the role of genetic factors in the incidence of this mental disorder, family imbalance and other anxiety factors play a role in the continuity of the disorder.2

Conduct disorder with a prevalence of 1 to 10 percent is a prevalent disorder in primary schools, similar to ADHD. It is 4 to 12 times more frequent among boys compared with girls.

Children with mixed ADHD have more risk factors compared with controls and children with ADHD inattentive type and also their families have more adversity compared with families of ADHD, inattentive type children and control.3

Conduct disorder is a stable set of behaviors characterized by aggression and violating other’s rights. It is associated with many other disorders including ADHD and is also related to several mental and social factors such as harsh parenting, family problems and lack of parental supervision. Many parents of children with conduct disorders have serious mental problems. In addition, the increased prevalence of drug abuse and dependency has a role in the incidence of conduct disorder.2 Piffiner et al reported that the association of conduct disorder and ADHD is significantly related to lack of family supervision, negative and non-effective behavior and the father’s antisocial personality.4

Studies have shown that 51% of children with bipolar parents have psychiatric disorders and most of them have MDD, ADHD and behavioral disorders.5 Moreover, other studies have reported a 13% prevalence of ADHD in children of drug-dependent parents and a 8% prevalence in cocaine dependent parents.6

Children with ADHD, which is commonly associated with conduct disorder, causes dysfunction in the family and parent-child relationship, and reduces the effective role of parents, increases the stress level and other psychiatric problems in the family.7 On the other hand, children with ADHD in a four-year follow-up showed development of BMD if they had a family history of this disorder.2 Considering the negative impact of parents' drug dependency and bipolar disorder, the present study aimed to determine the prevalence of ADHD and conduct disorder in children of parents with drug dependency or bipolar disorder.

Methods

In this case-control study, the case group consisted of patients with drug dependency and bipolar disorder hospitalized in Shahid Beheshti Hospital in Kerman who had children in the age range of 7 to 11 years. The controls consisted of healthy individuals with no drug dependency or any psychiatric disorder who had children in the same age range. The sample size was about 100 in three groups of parents with bipolar disorder, parents with drug dependency and the control group, considering α = 5% and the standard deviation of conduct disorder and ADHD scores, which was 1.250 in previous studies and d=0.16. The sample selection continued as far as possible to make an equal number of boys and girls including in each group.

Exclusion criteria were mental retardation in either parents or children, neurological and chronic somatic diseases. Furthermore, in the drug dependency group, patients with BMD, in the BMD group patients with drug dependency and in the control group patients with either drug dependency or BMD were excluded. Diagnosis of drug dependency and bipolar disorder was based on DSM-IV-TR which was carried out by two psychiatrists and a psychiatric assistant. Data were collected using Rutter's scale for assessing behavioral problems Form A (parents' form) and a demographic questionnaire.

Reliability and validity of this questionnaire has been investigated in Iran.8 This questionnaire includes 31 components including health related issues, habits, and 18 statements, which have three levels of answers of “not correct”, “correct to some extent” and “completely correct” and the scores for them are zero, one and two, respectively. The maximum total score for this questionnaire is 62 and the total score of 13 or higher is the cut off point showing behavioral disorder.

Diagnosis in this questionnaire includes conduct disorder, emotional disorder, non-distinctive and normal. A Rutter score of higher than 13, but equal scores of conduct disorder and emotional disorder is called non-distinctive disorder.

Data were analyzed with ANOVA, Chi-square and Tamhane's post-hoc test. SPSS11.5 was used for this purpose.

Results

Abnormal Rutter scores was generally 11.7%, 14% and 6.1% in children of drug dependent parents, bipolar parents and healthy parents, respectively and there was no significant difference between them. The frequency of hyperactivity disorder, conduct disorder and emotional disorder in children is presented in Table 1. There was no significant difference between conduct disorder and ADHD in girls and boys of each group. Table 2 shows the frequency of hyperactivity and conduct disorders in bipolar, drug dependent and healthy parents considering mothers' smoking during pregnancy. There was no significant correlations between smoking during pregnancy and the frequency of ADHD and conduct disorder in any of the groups. According to the results, the mean of hyperactivity raw scores in bipolar and drug dependency groups were significantly different from those of healthy groups (P = 0.001 and P = 0.006, respectively), but there was no significant difference between the bipolar and drug dependent groups in this regard. Regarding the frequency of conduct disorder between children of the three groups, no significant difference was seen. However, in the bipolar and drug dependent groups, the frequency of conduct disorder was higher than the healthy group.

Table 1

Frequency of conduct disorder, hyperactivity and emotional disorders in children of bipolar, drug dependent and healthy parents

Disorder Group/sex		Conduct Disorder	Hyperactivity	Emotional Disorder
Bipolar	Boys	6 (11.1%)	7 (12.9%)	7 (12.9%)
	Girls	5 (10.8%)	4 (8.6%)	8 (17.3%)
Drug dependent	Boys	5 (10.8%)	6 (13%)	10 (21.7%)
	Girls	3 (5.3%)	4 (7%)	7 (12.5%)
Controls	Boys	4 (8.3%)	1 (2%)	4 (8.3%)
	Girls	3 (6%)	(0%)	7 (14%)
Results		χ2 = 0.921	χ2 = 8.879	χ2 = 3.914
		P > 0.63	P > 0.12	P > 0.141

Table 2

Frequency of hyperactivity and conduct disorder in bipolar, drug dependent and healthy parents considering mother’s smoking during pregnancy

Disorder		Conduct disorder		Hyperactivity
Smoking by mothers during pregnancy	Groups	Positive	Negative	Positive	Negative
Bipolar	Smoking	(0%)	10 (100%)	(0%)	10 (100%)
	Not smoking	11 (12.2%)	79 (8/87%)	11(12.2%)	79 (87.8%)
Drug dependency	Smoking	(0%)	10 (100%)	1(10%)	9 (90%)
	Not smoking	8 (8.6%)	84 (91.4%)	9(9.7%)	83 (90.3%)
Controls	Smoking	(0%)	(0%)	(0%)	(0%)
	Not smoking	7 (7.1%)	91 (92.9%)	1(1%)	97 (99%)

In this study, the frequency and percentage of children with conduct disorder and hyperactivity disorder in all three groups was investigated based on gender and no significant difference was seen. However, the frequency of these two disorders was obviously higher in boys than girls. There was no significant difference between the conduct disorder in children with smoking mothers during pregnancy in the two bipolar and drug dependency groups. There was also no significant difference between children with ADHD considering smoking during pregnancy in the two groups of bipolar and drug dependent parents.

Discussion

In addition to the genetic role, stressful events, imbalanced families and other anxiety factors have a role in the incidence of ADHD or its continuity.2 The results of this study also shows that bipolar disorder in parents as a significant correlating factor may disturbs the balance of the family, creates anxiety and finally leads to behavioral problem in children. However, bipolar disorder in the parents increases the amount of trauma and other psychiatric disorders including mood disorders, psychosis and anxiety in children. Previous studies9 have shown that 51% of children with BMD parents have psychiatric disorders, the majority having ADHD, MDD and behavioral disorders. The results of the present study approve these results. Moreover, the present study found a 9.8% frequency of hyperactivity in children of drug dependent parents, which is significantly different from the controls with a 1% frequency (P = 0.006) showing the effect of drug dependency as a related factor in the incidence of psychiatric disorders in children and is in agreement with the results of previous studies,6 in which the prevalence of ADHD in children of semi-narcotic and cocaine dependent parents were separately studied and reported to be 13% and 8%, respectively.

Although there was no significant difference between the conduct disorder in the three groups of the study, the higher frequency of this disorder in BMD and drug dependent groups compared with the controls suggests that family problems including parent’s mental illness and drug abuse play a significant role in the incidence of conduct disorder.1 In the study of Chang et.al also children of BMD parents showed higher levels of destructive behavioral disorders compared with children of parents without any mood disorder.9 Furthermore, in the study of Hirshfield et al, the prevalence of behavioral disinhibition in children of BMD parents was reported to be significantly high.10

The results also showed that although the frequency of ADHD and disorders of the above mentioned groups were not significantly different between girls and boys, the frequency of both disorders was higher in boys than girls, and these results are almost in agreement with a controlled study in the United States, which reported a higher prevalence of ADHD and conduct disorder in boys compared with girls.2

In this study, there was no significant correlations between smoking during pregnancy and the frequency of ADHD and conduct disorder in any of the groups. However, other studies such as Bolton et al have shown that ADHD symptoms and antisocial behaviors have both been seen in children whose mothers had smoking during their pregnancy and these symptoms were more seen in children with smoking mothers.11 Line et al's study also showed that smoking mothers had children with a higher risk of ADHD compared with children with mothers who consumed alcohol or caffeine.12 The incidence of disorder in children was also related with the amount of smoking. In the study of Wakschlag et al, mothers who smoke more than half a pack of cigarettes during pregnancy had sons with conduct disorders significantly more than mothers who did not smoke.13 Silberg et al in a study on 538 twin boys reported that the relationship between mother’s smoking during pregnancy and conduct disorder symptoms of their sons was significant in cases whose mothers smoked ten or more cigarettes a day during pregnancy.14

Conclusion

ADHD and conduct disorder in children of parents with drug abuse disorders was higher than the control group, but was not different compared with the bipolar group. Therefore, it may be mentioned that any kind of mental disorder in parents may increase the risk of ADHD and conduct disorder in children. Further studies on the relationship between ADHD and conduct disorder in children and other mental disorders of parents may clarify this finding.

Limitations

For a more precise study and evaluation of ADHD and conduct disorder, it would had been better to use both Rutter's Form A (parents) and B (teachers) questionnaire, but since a great number of samples were selected from hospitalized patients in Shahid Beheshti Hospital, it was not possible to access the teachers to fill the Form B; therefore, just Form A was used in this study.

To increase the sensitivity of the test, it is better to conduct a structured clinical interview in addition to questionaire to improve the validity of diagnosis. This was not carried out due to the time limitation.

In this study, since the demographic questionnaires were mainly completed by fathers, and most of them did not have precise information about the number of cigarettes smoked by their wives; therefore, the amount of smoking during pregnancy may not be accurate.