Patterns and risk factors of illicit substance abuse by Sri Lankan teenagers: a case-control study

Illicit substance abuse among adolescents is an emerging public health challenge in Sri Lanka, yet evidence on independent risk factors, particularly among high-risk teenagers undergoing rehabilitation, remains limited. Understanding social, familial, peer and school-related determinants is essential to inform targeted prevention and intervention strategies.

A case-control study was conducted among adolescents aged 10-17 years. Cases (n=108) were teenagers admitted for inpatient rehabilitation for illicit substance abuse at the Youth Drug Addiction Prevention, Treatment and Rehabilitation Centre, Kandy, Sri Lanka. Age-matched and sex-matched controls were recruited from the outpatient department of North Colombo Teaching Hospital, Ragama. Data were collected using a structured questionnaire assessing individual, peer, family, school and psychosocial factors. Associations were examined using χ² tests, and independent risk factors were identified using multivariable logistic regression. Statistical significance was set at p<0.05.

Peer-related factors showed the strongest associations with substance abuse. Peer use of illicit substances (adjusted OR 32.16; p<0.001) and peer encouragement of substance use (adjusted OR 14.26; p<0.001) were the most powerful independent predictors. Other significant independent risk factors included association with antisocial peer groups (adjusted OR 10.4; p<0.001), parental separation (adjusted OR 5.34; p<0.001), perceived school neglect (adjusted OR 3.14; p<0.001), problematic social media use (adjusted OR 2.52; p=0.002) and perception of substance use as a means of gaining social popularity (adjusted OR 2.44; p=0.004). A high burden of psychological vulnerability was observed, with 46.3% reporting prior self-harm-related thoughts.

Illicit substance abuse among Sri Lankan teenagers is predominantly driven by peer influence, family disruption, school disengagement and social vulnerabilities. Prevention and intervention strategies should prioritise peer-focused approaches, family strengthening, school re-engagement and integrated mental health support.