Women dying as a result of drug abuse, poisoning or addiction is on the rise in England and Wales, but the number of male deaths has declined, new statistics show.
The Office of National Statistics said on Wednesday that in 2011, there were 1,772 male and 880 female drug poisoning deaths, involving both legal and illegal drugs, a 6% decrease since 2010 for males and a 3% increase for females.
The number of methadone related deaths of men in England and Wales also rose by more than a third last year to its highest rate since 1997.
The survey looked at coroners' reports into unnatural deaths, and noted which substances were killing the most people, and their habits before they died.
Drug-related deaths accounted for nearly one in eight deaths among people in their 20s and 30s in 2011.
The number of women committing suicide using drugs increased by 7% with 418 deaths reported in 2011.
In total, 1,605 people died in England and Wales who abused drugs or who were habitual drug addicts.
But men are still significantly more likely to die from drug abuse than women, despite the number of male drug poisoning deaths being at their lowest since 1994.
The Home Office's British Crime Survey for 201 showed that men were more than twice as likely as women to have used illicit drugs in the last year.
Men aged between 30 and 39 are the most likely to die, much higher than women of this age.
Gerv McGrath, director of community services for Addaction, told The Huffington Post UK that statistics were constantly in flux.
"One of the most interesting parts of the report is the age of those dying from opiate abuse, people in their 30s. Until recently, we had not really addressed the issue of long-term dependency.
"Many of these deaths are people leaving prison, there is no 'prison gate pickup' to help them, and their tolerance has become much lower, and they don't realise, so they start back on strong strains of the drug."
But young men are becoming less likely to die as a result of a severe drug addiction or drug abuse, deaths are at their lowest since records began.
The number of 18 to 24-year-olds entering treatment for heroin and crack use has halved over the last five years.
Approximately 30% of all drug-related poisoning deaths also contain a mention of alcohol, in addition to a drug.
The survey also looked closely at the most fatal drugs, with heroin and morphine responsible for 57% of deaths from drug poisonings, but heroin deaths have fallen in men 39% since 2009, but only fallen 4.5% for women, not changing significantly since 1997.
The survey said there was evidence of a "‘heroin drought’ in the UK... which has resulted in typical street heroin purity falling.
"Drugs workers were concerned that the heroin drought may result in more drug-related deaths, as users who had developed a reduced tolerance could overdose if they used a high quality batch of heroin. However, ONS data show the opposite trend with deaths involving heroin falling in recent years."
Some 486 deaths were linked to the heroin-substitute methadone - for men that meant a 36% rise and the highest rate since 1997.
The ONS said: "The increase in deaths involving methadone correlates with findings from the British Crime Survey showing the proportion of 16- to 59-year-olds using methadone in the last year increased significantly in 2010/11.
"In addition, the latest Druglink Street Drug Trends Survey found there had been an increase in the use of methadone (and other substances) by primary heroin users, possibly as a result of the heroin drought."
Campaigners have previously argued about the dangers of providing addicts with methadone, which was the biggest cause of drug deaths in Scotland last year.
Rupert Wolfe-Murray of Castle Craig addiction rehab clinic told The Huffington Post UK: "The problem is that methadone is highly addictive, some say worse than heroin.
"At the moment it seems that the only option available to injecting drug users is to prescribe methadone indefinitely."
McGrath told The Huffington Post UK that he believed the next few years would show a decline in drug-related deaths, and said the emphasis in drug treatment was shifting towards recovery, rather than replacing the substance long-term with a safer substitute like methadone for heroin addicts.
"Many stay in replacement for too long, and end up back on street drugs. We are missing opportunities to move them into recovery.
"We hope there will be a real change in the next few years when the change of strategy kicks in.
The number of deaths involving so-called ‘legal highs’ are low compared as are deaths involving cannabis, seven deaths in 2011, and the deaths usually involved more than one substance.
Two drugs appear to be significantly on the rise, causing more and more fatalities, barbiturates and helium.
Almost all of these deaths were suicides.