Using the logic favored by Democrats when criticizing GOP health care reform measures, we can say Medicare causes opioid addiction.  That's because statistics show that Medicaid recipients are about twice as likely to be prescribed opioids as are privately insured patients.

Allysia Finley writes in the Wall Street Journal:

Wisconsin Sen. Ron Johnson this summer highlighted a correlation between the ObamaCare Medicaid expansion and opioid overdoses. Data from the Centers for Disease Control and Prevention show that overdose deaths per capita rose twice as much on average between 2013 and 2015 in states that expanded Medicaid than those that didn't – for example, 205% in North Dakota, which expanded Medicaid, vs. 18% in South Dakota, which didn't. That's particularly striking since the energy boom boosted North Dakota's economy and employment. ...

[T]he disaggregated data show that the disparity between expansion and nonexpansion states with similar demographics and geography increased markedly after 2013. Between 2010 and 2013, overdose deaths rose by 28% in Ohio and 36% in Wisconsin. Between 2013 and 2015, they climbed 39% in Ohio, which expanded Medicaid, but only 2% in Wisconsin, which did not.

The effects are seen not just in deaths, but also in (expensive) hospital admissions:

Overdose deaths aren't the only measure of opioid abuse. Another is hospital and emergency-room admissions. According to the Agency for Healthcare Research and Quality, the number of opioid-related inpatient hospital stays nationwide (among states submitting data) that were paid for by Medicaid increased by about 40% between the fourth quarters of 2012 and 2014 – about four times the rate of growth in Medicaid enrollment. Patient stays covered by private insurance increased 4% during this period.

Finley further explains:

Medicaid patients may be more likely to be prescribed opioids – twice as likely, according to two studies, as privately insured individuals. A recent study by Express Scripts Holding found that about a quarter of Medicaid patients were prescribed an opioid in 2015.

State Medicaid programs also favor generics over more expensive branded painkillers with abuse-deterrent formulas. According to the Express Scripts study, generics accounted for 90% of Medicaid opioid medication claims. Large doses of oxycodone, methadone and fentanyl can be obtained cheaply with a Medicaid card and resold for a nice profit on the black market. Sen. Johnson's review of recent open-source court files and news articles turned up 261 defendants who had been convicted of improperly using Medicaid cards to obtain prescription opioids.

There is no consideration here of what personal characteristics may differ between Medicaid and privately insured patients.  Obviously, Medicaid patients are by definition poorer, but progressive ideology forbids any speculation as to levels of personal responsibility differing between self-supporting people and those unable to take care of their own health care needs.

Twinned with Medicare, Medicaid stars in the left's efforts to impose single-payer health care on America.  But these statistics suggest that such a policy could heighten the opioid crisis.