Roland Lamb is seeing older Philadelphians walk through the doors of the city's drug-treatment centers: seniors who are addicted to painkillers, booze, or both, or who want to get off their chronic-pain medications.

"They call because their doctors have died and retired, and their new docs won't give them the ongoing painkiller prescriptions," said Lamb, deputy commissioner for the city's Department of Behavioral Health and Intellectual Disability Services, and a teacher at University of the Sciences and Villanova. "Now, they're having episodes of withdrawal from oxycodone or benzo painkillers like Valium, Klonopin, Xanax, Tramadol, Librium — you name it."

He has received requests for help from people 70 and older, asking about getting into drug rehab.

It turns out that the older we get, the more likely we are to become addicted to such painkillers as opioids, or alcohol, or both — and possibly die of an overdose. New statistics show that the number of people 50 and older admitted to substance-abuse treatment programs increased 136 percent between 1992 and 2010, according to the U.S. Substance Abuse and Mental Health Services Administration.

Alcohol is the most common reason that baby boomers seek rehab or detox treatment, but the proportion of admissions of people over 50 for heroin abuse nearly doubled and for cocaine use more than tripled over the 1992-2010 period, the agency says.

Why? A few reasons: Doctors more freely prescribe opiates, leading to addiction. As we age, we don't metabolize prescription drugs as quickly, thereby leading to higher rates of accidental overdose. And, older generations tend to take drugs longer without questioning their doctors.

To better understand the numbers,, a referral service for treatment centers, collected overdose statistics from the U.S. Centers for Disease Control and Prevention's WONDER CDC database. looked at six classifications of drugs: stimulants; alcohol; benzodiazepines; cocaine; heroin; and prescription opioids.

Seniors are most vulnerable. "Although it might seem counterintuitive, more people in America are dying from legal opioid abuse than from illicit drug abuse," the study found. Over a 15-year period (1999-2014), deaths in the youngest age group, 15 to 24, rose from 320 to 2,735. Deaths among those ages 25 to 34 increased from 1,757 to 10,475. In the 35-to-44 age group, deaths rose from 4,225 to 10,475, and among those 55 to 64 increased from 226 to 7,486.

The steepest increase in overdose deaths came among those 65 to 74: from 16 deaths in 1999 to 680 in 2014, up 4,150 percent.

According to the Centers for Disease Control, the number of painkillers sold in the United States has nearly quadrupled since 1999, but the amount of reported pain hasn't changed. In Philadelphia in 2016, 86 out of 907 total drug deaths were among those age 60 or older. In 51 of those deaths, an opioid was present, according to a spokesman for the medical examiner.

As our bodies age, we lose the ability to effectively clear drugs out of our system. A standard dose of opioids for a younger person could be a fatal overdose for an elderly person.

From 1999 to 2014, the study found, senior men experienced a 775 percent increase in opioid overdoses, from 16 to 140 deaths. Senior women, on the other hand, experienced a 1,682 percent change from 1999 to 2014, with the number of deaths rising from 11 to 196.

Compared with senior men, older women are more likely to suffer from chronic pain and may use opioids longer, found. Although men are more likely to seek treatment, women may feel embarrassed to admit they need help.

Alternative painkillers. Robert Platshorn, founder of the Silver Tour (, an advocacy group for cannabis in geriatric medicine, argues that medical marijuana can serve as a less harmful painkiller and lead to fewer overdoses.

"There are millions of junkie seniors taking oxy or fentanyl because they're considered a natural prescription for physicians who treat seniors in pain. So all that opioid addiction can be avoided" by prescribing medical marijuana, in either pill, gummy or oil form, Platshorn said.

"There was a philosophy for many years that you couldn't get addicted to these painkillers," said Jen Smith, acting secretary of Pennsylvania's Department of Drug and Alcohol Programs. "Doctors prescribed them not thinking about the possibility of addiction."

Combine that with a population more likely to break a hip and need surgery, she said, and "seniors also tend not to hear doctor's 'as needed' instructions. If they get 30 days of painkiller, they'll take all 30."

Prescription drug monitoring. To empower medical professionals to identify addicted patients, New Jersey and Pennsylvania are among the states with Prescription Drug Monitoring Programs. Doctors, dentists and pharmacists now can access controlled-substance prescription histories.

"It helps identify 'doctor shoppers,' or, in the elderly, people who've already been prescribed opioids but forgot," Smith said.