Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 2009.

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And as Forbes contributor David DiSalvo noted recently, a plethora of studies on omega-3s and mental health have found benefits but definitive links between omega-3s and brain health have yet to be established.

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Several studies have also linked the drug to mental health problems, such as depression and schizophrenia, and respiratory illness.

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Most of these studies show no ill effects of benzodiazepines on either mental functioning or physical health.

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In the past decade, at least 20 studies have shown positive correlations between consuming fish oil supplements and improved mental health.

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The longitudinal studies that have been done have shown no difference in emotional and mental health between children raised by gay and lesbian parents and children raised by heterosexual parents.

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Christopher Davis, an anthropologist at the University of London's School of Oriental and African Studies (SOAS), said traditional healers can play a role as mental health providers.

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Prof John Britton, director of the UK Centre for Tobacco Control Studies at the University of Nottingham and report chairman, said people with mental health disorders might find it harder to quit smoking but that did not mean they did not want to stop.

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Studies in India show that lay health workers also help people to better accept mental illness and necessary treatments.

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Studies indicate that, especially for seniors, having friends can improve both physical and mental health.

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