Isn't marijuana linked to mental illness though? This doesn't sound encouraging, I've no interest in trying the drug but this would put me off if I were thinking about it.
MENTAL HEALTH, BRAIN FUNCTION, AND MEMORY
It has been suggested that marijuana is at the root of many mental disorders, including acute toxic psychosis, panic attacks (one of the very conditions it is being used experimentally to treat), flashbacks, delusions, depersonalization, hallucinations, paranoia, depression, and uncontrollable aggressiveness. Marijuana has long been known to trigger attacks of mental illness, such as bipolar (manic-depressive) psychosis and schizophrenia. This connection with mental illness should make health care providers for terminally ill patients and the patients themselves, who may already be suffering from some form of clinical depression, weigh very carefully the pros and cons of adopting a therapeutic course of marijuana.
In the short term, marijuana use impairs perception, judgment, thinking, memory, and learning; memory defects may persist six weeks after last use. Mental disorders connected with marijuana use merit their own category in the Diagnostic and Statistical Manual of Mental Disorders (DSM) IV, published by the American Psychiatric Association. These include Cannabis Intoxication (consisting of impaired motor coordination, anxiety, impaired judgment, sensation of slowed time, social withdrawal, and often includes perceptual disturbances; Cannabis Intoxication Delirium (memory deficit, disorientation); Cannabis Induced Psychotic Disorder, Delusions; Cannabis Induced Psychotic Disorder, Hallucinations; and Cannabis Induced Anxiety Disorder.
In addition, marijuana use has many indirect effects on health. Its effect on coordination, perception, and judgment means that it causes a number of accidents, vehicular and otherwise.
http://cyber.law.harvard.edu/evidence99/marijuana/Health_1.html
Sounds not too different from what my Mom told me about alcohol issues...her more memorable moments in over 30 years professionally in mental health/detox and rehab were alcohol (especially hard liquor) and the nasty stuff like crack etc, I don't recall pot being mentioned...