The Government should stop building prisons and invest in treatment for addicts and effective health and social care, campaigners have said.
Billions of pounds of public money is being wasted on a prison system which cannot reasonably cope with the burden of public health demands, the Prison Reform Trust said.
The Trust, in a new report, used official figures drawn from a wide range of sources, including new parliamentary questions, to show "the extent and impact of the rise in the prison population in recent years despite the fall in overall crime".
It said that on June 12 the prison population in England and Wales was 83,001 - a 38% increase since the Government came to power in 1997, and that at the end of April, 82 out of the 140 prisons in England and Wales were officially overcrowded.
On arrival in local prisons, 70-80% of prisoners test positive for Class A drugs.
In almost half of violent crimes (48%) the victim believed the offender or offenders to be under the influence of alcohol.
A survey by the Ministry of Justice found that more than a quarter of newly sentenced prisoners reported a long-standing physical disorder or disability, the Trust said.
More than half of all elderly prisoners suffered from a mental disorder.
Juliet Lyon, director of the Trust, said: "Everyone knows that drink and drugs drive crime, and that it is cruel and inhumane to imprison people who are mentally ill or suffer from profound learning disabilities, so why are ministers still hell bent on pouring public money into prison building when they should be investing in treatment for addicts and effective health and social care instead?
"Government must get a grip and deliver on its promise to reduce social exclusion. Ever-growing numbers of sick people recycled around a bleak prison system is not the way to do it. It's time to stop mindless prison building and cut crime by sensibly improving public health."
