This group of disorders include substances or behaviors that activate the reward system in the brain.  Individuals who have diagnoses in this section develop maladaptive behaviors and have difficulty regulating their activity in relation to these substances or rewarding behaviors.

Substance (Drug) Use Disorders involve a problematic pattern of substance resulting in significant impairment or distress, lasting at least 12 months, in which the patient has some or many of the following symptoms: difficulty fulfilling obligations at work, school, or with family, using the substance in a situation where it could be physically hazardous, has legal problems as a result of substance use, has recurring problems in social situations and relationships, exhibits excessive use of the substance, is unable to stop using of the substance, spends excessive time using the substance, use of the substance interferes with social or work relationships, has cravings to use the substance, continued use despite the worsening of physical or psychological symptoms. Patients with Substance Use Disorders can develop tolerance, which is the need for more of the substance to get the same effect, or withdrawal, in which a recognized set of symptoms come on with discontinuation of the substance.

Patients may develop a Substance Use Disorder to a wide range of different substances such as:

•  Stimulants such as amphetamines or methamphetamine
•  Cannabis (marijuana)
•  Cocaine
•  Hallucinogens such as LSD or mushrooms
•  Inhalants such as paint or glue
•  Nicotine
•  Opioids and opiates such as heroin or pills such as oxycodone
•  Phencyclidine (PCP)
•  Sedatives and antianxiety medications such as phenobarbital, benzodiazepines such as Xanax, or sleeping medications such as Ambien
•  Tobacco
•  Caffeine

Patients may develop a Substance Use Disorder to any addictive substance, or any combination of addictive substances.

Substance abuse or dependence can cause depression, mania, anxiety, psychosis, and other psychological and psychiatric symptoms. These symptoms typically reduce over time if they are solely caused by the substance itself. Such substance-induced symptoms must be taken into account before making a separate diagnosis of another psychiatric disorder such as a Mood Disorder, an Anxiety Disorder, or a Psychotic Disorder. However patients with these diagnoses often abuse or become dependent on substances as a means of self-medication and thus may have both a psychiatric diagnosis and a Substance Use diagnosis (Dual Diagnosis patients).  Substance abuse can also cause clinically significant Withdrawal symptoms that may require treatment by a psychiatrist or other medical professional.

Pathological Gambling is a condition in which the individual shows repeated maladaptive gambling behavior. Patients with Pathological Gambling are preoccupied with gambling, require increased gambling activity in order to obtain the desired excitement, have unsuccessfully tried to cut down or stop gambling, and become restless and irritable when trying to stop gambling. Additional symptoms include gambling to escape problems, quickly returns to gambling after significant losses to make up the losses, lies to others in order to conceal the extent of gambling, has committed illegal acts such as forgery in order to obtain money for gambling, relies on others to provide money in order to avoid desperate financial consequences from gambling, and has lost a job, a relationship, a educational opportunity, or a career opportunity because of gambling.