Seoul, Aug 8 (IANS): Parents, please take note. A new study has found that smoking and depression in parents may increase the risk of attention-deficit hyperactivity disorder (ADHD) in their children.

According to the researchers, the results illuminate the need to increase awareness of parental factors that have the potential to contribute to ADHD in children.

The study, published in the journal Asia Pacific Psychiatry, could be incorporated into 'stop smoking' campaigns or depression self-recognition programmes.

"Our finding added to the evidence supporting the need for ADHD prevention strategies and would be helpful in the development of effective public prevention policies intended to promote healthy family environments," said co-author Jin-won Kwon from the Kyungpook National University in South Korea.

For the study, the research team involved 23,561 children and adolescents aged less than 18 years to investigate the risk factors associated with ADHD in them, using a nationally representative sample of the population.

ADHD was assessed using a self-reported diagnosis of ADHD. Among the patients, boys and girls constituted 78 per cent and 22 per cent, respectively.

The researchers considered various risk factors including demographics, obesity, and family environment (household income, parental age, depression in adults in the household, and exposure to environmental smoke at home).

The relationship between ADHD and the considered risk factors was evaluated using multiple logistic regression.

The study identified parent's smoking and depression as family environmental factors associated with children's ADHD.

The annual prevalence of physician-diagnosed ADHD showed a four-fold increase (0.35 per cent in 2005 and 1.36 per cent in 2014) over the study period.