Substance use problems and associated psychiatric symptoms among adolescents in primary care

Substance use disorders (SUDs) are associated with other mental disorders in adolescence, but it is unclear whether less severe substance use problems (SUPs) also increase risk. Because youths with SUPs are most likely to present first to their site of primary care, it is important to establish the presence and patterns of psychiatric comorbidity among adolescent primary care patients with subdiagnostic use of alcohol or other drugs. The objective of this study was to determine the association between level of substance use and psychiatric symptoms among adolescents in a primary care setting.

Patients who were aged 14 to 18 years and receiving routine care at a hospital-based adolescent clinic were eligible. Participants completed the Problem Oriented Screening Instrument for Teenagers Substance Use/Abuse scale, which is designed to detect social and legal problems associated with alcohol and other drugs, and the Adolescent Diagnostic Interview, which evaluates for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnoses of substance abuse/dependence and 8 types of psychiatric symptoms. We examined gender-specific associations of no/nonproblematic substance use (NSU), SUP, and SUD with psychiatric symptom presence (any symptoms within each type), score (symptom scores summed across all types), and number of types (number of different symptom types endorsed).

Of 538 adolescents (68% female; mean +/- standard deviation age: 16.6 +/- 1.4 years), 66% were classified with NSU, 18% with SUP, and 16% with SUD, and 80% reported having at least 1 type of psychiatric symptom in the previous 12 months. Symptoms of anxiety were most common (60% of both boys and girls), followed by symptoms of depression among girls (51%) and symptoms of attention-deficit disorder (ADD) among boys (47%). Compared with those with NSU, youths with SUP and those with SUD were more likely to report symptom presence for several types of psychiatric symptoms. Girls with SUP or SUD had increased odds of reporting symptoms of mania, ADD, and conduct disorder; girls with SUD were at increased risk for symptoms of depression, eating disorders, and hallucinations or delusions. Boys with SUP had increased odds of ADD symptoms, whereas boys with SUD had increased odds of reporting hallucinations or delusions. Boys with SUP or SUD had increased odds of reporting symptoms of conduct disorder. Youths with SUP and SUD also had higher psychiatric symptom scores and reported a wider range of psychiatric symptom types (number of types) compared with youths with NSU.

Like those with SUD, adolescents with subdiagnostic SUP were at increased risk for experiencing a greater number of psychiatric symptoms and a wider range of psychiatric symptom types than youths with NSU. Specifically, adolescents with SUP are at increased risk for symptoms of mood (girls) and disruptive behavior disorders (girls and boys). These findings suggest the clinical importance of SUP and support the concept of a continuum between subthreshold and diagnostic substance use among adolescents in primary care. Identification of youths with SUP may allow for intervention before either the substance use or any associated psychiatric problems progress to more severe levels.