The team specifically looked in detail at the prevalence and treatment of drug use disorders (DUDs) as described in the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5).
They poured over data taken from interviews with 36,309 adults, and the study focused on amphetamine, cannabis, club drug, cocaine, hallucinogen, heroin, nonheroin opioid, sedative/tranquilizer or solvent/inhalant use disorders.
Results of the investigation showed a level of prevalence that might, to many, be surprising: 3.9% of Americans - around 9.1 million people - had a 12-month DUD diagnosis, and 9.1% had a lifetime diagnosis.
Specific sections of society were found to have an increased rate of DUDs. The following groups were most affected:
- Men
- White and Native American individuals
- Young, and previously married or never married adults
- Those with lower income and education
- Individuals who live in the West of America.
The study also linked a number of other factors to 12-month DUDs, including:
- Major depressive disorder
- dysthymia (persistent mild depression)
- Bipolar
- Post-traumatic stress disorder
- Personality disorders.
And, with lifetime DUDs, the following factors were added to that list:
The study found that individuals with a DUD diagnosis experienced lower social functioning, mental health and role emotional functioning.