Primary Mental Disorders
Opioid-Induced Disorders may be characterized by symptoms (e.g., depressed mood) that resemble primary mental disorders (e.g., Dysthymia versus Opioid-Induced Mood Disorder, With Depressive Features, With Onset During Intoxication). Opioids are less likely to produce symptoms of mental disturbance than are most other drugs of abuse and, in some instances, will even reduce symptoms. In these cases, mental symptoms or disorders may emerge after opioid use is discontinued.
Alcohol Intoxication and Sedative, Hypnotic, or Anxiolytic Intoxication can cause a clinical picture that resembles Opioid Intoxication. A diagnosis of Alcohol or Sedative, Hypnotic, or Anxiolytic Intoxication can usually be made based on the absence of pupillary constriction or the lack of a response to a naloxone challenge. In some cases, intoxication may be due both to opioids and to alcohol or other sedatives. In these cases, the naloxone challenge will not reverse all of the sedative effects. The anxiety and restlessness associated with Opioid Withdrawal resemble symptoms seen in Sedative, Hypnotic, or Anxiolytic Withdrawal. However, Opioid Withdrawal is also accompanied by rhinorrhea, lacrimation, and pupillary dilation, which are not seen in sedative-type withdrawal. Dilated pupils are also seen in Hallucinogen Intoxication, Amphetamine Intoxication, and Cocaine Intoxication. However, others signs or symptoms of Opioid Withdrawal such as nausea, vomiting, diarrhea, abdominal cramps, rhinorrhea, or lacrimation are not present. Opioid Intoxication and Opioid Withdrawal are distinguished from the other Opioid-Induced Disorders (e.g., Opioid-Induced Mood Disorder, With Onset During Intoxication) because the symptoms in these latter disorders are in excess of those usually associated with Opioid Intoxication or Opioid Withdrawal and are severe enough to warrant independent clinical attention.