There are two groups of substance-related disorders in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013): substance-induced disorders and substance use disorders (SUDs). Substance-induced disorders include intoxication, withdrawal, and substance-induced mental disorders. SUDs are problematic symptoms that occur when individuals continue to use substances, despite experiencing impairment or distress. Substance-related disorders are listed separately for each of the 11 substance groups (alcohol, caffeine, cannabis, phencyclidine, other hallucinogens, inhalants, opioids, sedatives, hypnotics and anxiolytics, stimulants, tobacco, and other substances). The DSM-5 combines the categories of abuse and dependence into the single disorder of SUD with mild, moderate, and severe subclassifications based on the number of criteria met. Anyone meeting any two of the 11 criteria during the same 12-month period receives a SUD diagnosis. The criteria also include a remission specifier (in early remission, in sustained remission, on maintenance therapy, in a controlled environment).
Behavioural addictions, which are characterised by impairment of control rather than physiological dependence, may involve gambling, internet use, video games, shopping, exercise, work, eating, and sex. Behavioural addiction is not included as a diagnostic category in the DSM-5 due to insufficient evidence to establish diagnostic criteria and course descriptions. However, gambling disorder, which was formerly an impulse control disorder known as pathological gambling, is now included as a substance-related and addictive disorder. Gambling disorder is defined as persistent and recurrent problematic gambling behaviour leading to clinically significant impairment or distress. The diagnosis requires endorsement of five of nine criteria within the previous 12 months and includes specifiers for course (episodic, persistent), remission (early, sustained) and current severity (mild, moderate, severe). Moreover, internet gaming disorder (IGD) is included as a condition for further study. IGD is defined as repetitive use of internet-based games, often with other players, which leads to significant issues with functioning. The DSM-5 requires endorsement of five of nine criteria within the previous 12 months and includes current severity specifiers (mild, moderate, and severe).
A national survey by the Australian Institute of Health and Welfare (AIHW, 2014) indicates tobacco use in Australia has steadily declined since 1993; by 2013, 60% of individuals reported they had never smoked. Nearly 80% (78.3%) reported having consumed alcohol in the previous 12 months, with men (82%) reporting higher rates of alcohol consumption than women (76%).