The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), published by the American Psychiatric Association in 2000, defined "Cannabis Dependence" as follows:
Cannabis abuse: A destructive pattern of cannabis use, leading to significant social, occupational, or medical impairment.
Must have three (or more) of the following, occurring when the cannabis use was at its worst:
Cannabis tolerance: Either need for markedly increased amounts of cannabis to achieve intoxication, or markedly diminished effect with continued use of the same amount of cannabis.
Greater use of cannabis than intended: Cannabis was often taken in larger amounts or over a longer period than was intended
Unsuccessful efforts to cut down or control cannabis use: Persistent desire or unsuccessful efforts to cut down or control cannabis use
Great deal of time spent in using cannabis, or recovering from hangovers
Cannabis caused reduction in social, occupational or recreational activities: Important social, occupational, or recreational activities given up or reduced because of cannabis use
Continued using cannabis despite knowing it caused significant problems: Continued cannabis use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been worsened by cannabis."
Alan J. Budney, PhD, Professor of Psychiatry and Researcher at the University of Arkansas Center for Addiction Research, stated in his Oct. 2001 article "Marijuana Abstinence Effects in Marijuana Smokers Maintained in Their Home Environment," published in the Archives of General Psychiatry:
"This study validated several specific effects of marijuana abstinence in heavy marijuana users, and showed they were reliable and clinically significant.
These withdrawal effects appear similar in type and magnitude to those observed in studies of nicotine withdrawal...
Craving for marijuana, decreased appetite, sleep difficulty, and weight loss reliably changed across the smoking and abstinence phases. Aggression, anger, irritability, restlessness, and strange dreams increased significantly during one abstinence phase, but not the other."
Jack E. Henningfield, PhD, Associate Professor of Behavioral Biology at Johns Hopkins University School of Medicine, and Neal L. Benowitz, MD, Chief of the Division of Clinical Pharmacology and Experimental Therapeutics at the University of California at San Francisco, in an Aug. 2, 1994 New York Times article titled "Is Nicotine Addictive? It Depends on Whose Criteria You Use," and Daniel M. Perrine, Phd, Associate Professor of Chemistry at Loyola College in Maryland, in his 1996 book The Chemistry of Mind-Altering Drugs: History, Pharmacology, and Cultural Context, ranked the addictiveness of six drugs, with 1 being the most addictive, as shown in the chart below:
The Institute of Medicine published in its Mar. 1999 report titled "Marijuana and Medicine: Assessing the Science Base":
"In summary, although few marijuana users develop dependence, some do. But they appear to be less likely to do so than users of other drugs (including alcohol and nicotine), and marijuana dependence appears to be less severe than dependence on other drugs...
Adolescents, especially troubled ones, and people with psychiatric disorders (including substance abuse) appear to be more likely than the general population to become dependent on marijuana...
Some controlled substances that are approved medications produce dependence after long-term use; this, however, is a normal part of patient management and does not generally present undue risk to the patient."
Colin Blakemore, PhD, Chair of the Department of Physiology at Oxford University, and Leslie Iversen, PhD, Professor of Pharmacology at Oxford University, wrote in their editorial "Cannabis, Why It Is Safe," published in The Times [United Kingdom] on Aug. 6, 2001:
"For some users, perhaps as many as 10 per cent, cannabis leads to psychological dependence, but there is scant evidence that it carries a risk of true addiction. Unlike cigarette smokers, most users do not take the drug on a daily basis, and usually abandon it in their twenties or thirties.
Unlike for nicotine, alcohol and hard drugs, there is no clearly defined withdrawal syndrome, the hallmark of true addiction, when use is stopped."
The Merck Manual of Diagnosis and Therapy stated in Section 15, "Psychiatric Disorders," Chapter 195, "Drug Use and Dependence" and published on its website (accessed Nov. 20, 2002):
"Any drug that causes euphoria and diminishes anxiety can cause dependence, and cannabis is no exception. However, heavy use and complaints of inability to stop are unusual.
Cannabis can be used episodically without evidence of social or psychological dysfunction.
The term dependence probably is misapplied to many users. No withdrawal syndrome occurs when the drug is discontinued, but some heavy users report disrupted sleep and nervousness when they stop."
John Cloud, Staff Writer for Time magazine, stated in his Nov. 4, 2002 article "Is Pot Good For You?":
"Those who believe you can't become physically or psychologically dependent on marijuana are wrong. At least three recent studies have demonstrated that heavy pot smokers who quit can experience such withdrawal symptoms as anxiety, difficulty sleeping and stomach pain.
On the other hand, the risk of becoming dependent on marijuana is comparatively low. Just 9% of those who have used the drug develop dependence. By comparison, 15% of drinkers become dependent on alcohol, 23% of heroin users get hooked, and a third of tobacco smokers become slaves to cigarettes."
The Spiritual Science Research Foundation, a volunteer non-profit organization, told ProCon.org in a Dec. 24, 2006 email:
"In 96% cases of addictions the root cause is possession by ghosts or spirits. In fact, seemingly addictive substances, including marijuana, contribute to a maximum of 3% of the reasons why people get addicted.
However when a person who is not possessed by ghosts to begin with, regularly smokes marijuana, it leaves him vulnerable to an attack by an unseen entity. This is because spirits/entities rush to take advantage of this weakness or vulnerability in a person to affect or acquire control over him. Thus what could have possibly begun as a willful intake of marijuana soon gets out of control and the person becomes an addict under the influence of the entity. More often than not at this point in time it is beyond the control of the person to give up the habit.
Thus as per spiritual research findings, regular marijuana uptake has a strong correlation with the person being seized by a spirit/entity and becoming an addict. These entities possess people mainly to satisfy their own craving for the addictive substance, as they cannot experience it due to lack of their own physical body. Another common reason is to trouble the person by making them addicted."
Carolyn Coffey, Associate Fellow, Senior Research Officer and Epidemiologist at the Murdoch Children's Research Institute in Australia, stated in an Apr. 2, 2003 press release announcing his Feb. 2003 article "Adolescent Precursors of Cannabis Dependence: Findings from the Victorian Adolescent Health Cohort," published in the British Journal of Psychiatry:
"It's the threshold change to regular use that provides enough exposure to the drug to lead to dependence... By contrast, problematic drinking in the teenage years reduces the risk of cannabis dependence. This may reflect a social process in which young people select either a predominantly alcohol-using or cannabis-using lifestyle."
Suresh Kumar, MD, Psychiatrist Consultant for the United Nations Office on Drugs and Crime, told The Times of India in a July 26, 2003 article titled "Narcotic Toffees Could Be A Gateway Drug For Addiction":
"[T]he euphoria caused by a particular substance makes the user go back to it once again.
Repeated use would lead to a psychological craving for it and thus cause addiction. Though cannabis [marijuana] and its derivatives are not known to develop physical dependence as opium derivatives, including heroin, and alcohol do, they are capable of developing a mental craving that could be overwhelming for the users."