How can we tell if someone is abusing or addicted to drugs? Refer to DSM and ICO-10
Drug addiction is a complex illness. The path to drug addiction begins with the act of taking drugs. Over time, a person's ability to choose not to take drugs is compromised. This in large part is a result of the effects of prolonged drug use on brain functioning, and thus on behavior.
Addiction, therefore, is characterized by compulsive, drug craving, seeking, and use that persists even in the face of negative consequences.
You asked, "How can we tell if someone is abusing or addicted to drugs?"
I. Using the Diagnostic and Statistical Manual - III - R [DSM-III-R is not currently used but has historical utility.] at least three of the following are necessary; some of the symptoms of the disturbance must have persisted for at least one month or have occurred repeatedly over a longer period of time:
1. Substance is often taken in larger amounts or over longer period than intended
2. Persistent desire or one or more unsuccessful efforts to cut down or control substance use
3. A great deal of time is spent in activities necessary to get the substance (e.g., theft), taking the substance (e.g., chain smoking), or recovering from its effects
4. Important social, occupational, or ...
In reference to DSM and ICO-10 classification schemes, this solution identifies the signs and symptoms that diagnose someone who is abusing or addicted to drugs.