A team of researchers from the University of Hawaii assessed the impact of cigarette smoking and caffeine intake on the mental health of people who participate in polysubstance abuse, concluding that caffeine use in particular can have a substantially negative mental health impact on these individuals. Polysubstance abuse and polydrug abuse are two terms that doctors, researchers and public health officials use to identify the simultaneous abuse of at least two legal or illegal mind-altering substances. This pattern of substance intake is noted for the increased health risks it poses. Polysubstance Abuse Technically speaking, polysubstance or polydrug intake occurs whenever a person simultaneously or nearly simultaneously consumes any combination of mind-altering substances. Since most alcohol consumers smoke cigarettes, this means that most drinkers are polysubstance users. However, doctors, researchers and public health officials tend to use a more narrow definition when describing polysubstance abuse. This definition typically includes cases of excessive drug, medication and\/or alcohol intake, which often involve people affected by substance use disorder (a diagnosis that includes both substance addiction and impairing substance abuse). Noted reasons for engaging in a pattern of polysubstance abuse include a desire to experience a higher level of substance-related mind alteration and the use of one substance to offset some of the negative physical or mental sensations associated with the intake of another substance. Particularly dangerous combinations of substances include alcohol and sedative-hypnotic medications called benzodiazepines, benzodiazepines and any opioid drug or medication, cocaine and alcohol, MDMA (Ecstasy, Molly) and alcohol, and two or more stimulant substances (including the high-caffeine products known widely as energy drinks). Known potential consequences of polysubstance abuse include fatal and nonfatal cases of substance overdose. Smoking and Caffeine Use Recent figures from the Centers for Disease Control and Prevention indicate that about 18 percent of all American adults (i.e. about 42 million people) smoke cigarettes. Most habitual smokers are addicted to nicotine, the mind-altering ingredient found in cigarettes and other tobacco products. In turn, nicotine addiction is one of the key indicators of tobacco use disorder, a mental health diagnosis established and defined by the American Psychiatric Association. Close to half a million Americans die from smoking-related causes every year; this is equivalent to 20 percent of all annual deaths. The average American consumes about 300 mg of caffeine per day, according to figures compiled by the U.S. Food and Drug Administration. This is the rough equivalent of two to three cups of coffee. In addition to coffee, common sources of caffeine include caffeinated sodas, caffeinated teas and energy drinks. Impact on Polysubstance Abusers\u2019 Mental Health In a study published in the November\/December 2014 Journal of Addiction Medicine, the University of Hawaii researchers used data gathered from a group of adults in treatment for polysubstance-related issues to determine if cigarette use and caffeine intake can significantly harm the mental health of polysubstance abusers. Each of these adults self-reported his or her use of cigarettes and caffeine just prior to beginning one of the counseling sessions that formed part of his or her treatment. Following the counseling session, each participant took two mental health screening tests: the Beck Depression Inventory II\u2014designed to identify potentially diagnosable cases of depressive illness\u2014and the State-Trait Anxiety Inventory, designed to identify potentially diagnosable cases of various anxiety disorders. After reviewing the results of the screening tests, the researchers concluded that the study participants who consumed coffee had substantially higher scores on the Beck Depression Inventory than the participants who did not consume coffee. In fact, the coffee drinkers had more than twice the number of depression indicators (20.3) than the non-coffee drinkers (9.2). Interestingly, the same results did not apply to study participants who consumed a source of caffeine other than coffee. The researchers concluded that neither caffeine use nor cigarette\/tobacco use led to higher scores on the State-Trait Anxiety Inventory. They also concluded that cigarette\/tobacco use did not lead to higher depression scores. Overall, the study\u2019s authors found that caffeine intake (particularly coffee intake) is linked to significantly increased odds of depression in polysubstance-abusing adults. They believe that the amount of coffee habitually consumed by an affected individual may have an important impact on that person\u2019s chances of developing depression-related problems while taking part in substance treatment programs. They also believe that screenings for coffee intake may help such programs identify those people most likely to experience depression.