S93. ADHD SYMPTOMS AND DAILY SMOKING AT AGE 15–16 YEARS AND PSYCHOTIC DISORDER IN EARLY ADULTHOOD. FINDINGS FROM THE NORTHERN FINLAND BIRTH COHORT 1986 STUDY
Authors: Niemelä Solja , Peltonen Teemu , Koskela Jari , Mustonen Antti , Miettunen Jouko , Hurtig Tuula 
Published: May 2020

Abstract

Background
Association between smoking with both ADHD(1) and psychosis(2) has been explained by self-medication of ADHD and psychotic symptoms with nicotine use(3). Persons with psychosis also share impairments with persons with ADHD: e.g. inattention is a feature of both of these disorders(3).
Aim of this study was to investigate the association between ADHD symptoms and adolescent smoking in relation to psychotic disorder in young adulthood.

Methods
The Northern Finland Birth Cohort 1986 Study includes 99% of all births (n=9432) in the region. Participants with information on ADHD symptoms and daily smoking at age 15–16 years were included (n=5858, 48,7% male, 62.1% of the original study population). ADHD symptoms were evaluated by parents, who filled in the Strengths and Weaknesses of ADHD Symptoms and Normal Behaviors (SWAN) questionnaire. SWAN comprises ADHD symptoms (inattention, hyperactive-impulsive, combined) rated from 3 (far below average) to -3 (far above average). Information on psychiatric diagnoses was collected from four national registries until the end of year 2016. Associations between daily smoking and ADHD symptoms were analyzed using multiple linear regression. Sex, family structure, frequent alcohol intoxication, illicit drug use, and psychotic experiences at age 15–16 years were used as covariates. Analyses were done separately according to the psychiatric diagnosis status at age 30–31 years: no psychiatric diagnosis; any psychiatric diagnosis other than psychosis; any psychotic disorder.

Results
Among participants with psychotic disorder (n=119), daily smokers had higher inattention mean scores compared to non-smokers (-6.5 vs. 0.03, p-value=0.001, effect size (es)=0.8). Among those without psychiatric disorders (n=4618), daily smokers had higher scores in all SWAN domains compared to non-smokers: inattention (-8.9 vs. -3.6, p-value&lt;0.001, es=0.6); hyperactive-impulsive (-13.3 vs. -8.8, p&lt;0.001, es=0.5); and combined (-22.2 vs. -12.5, p&lt;0.001, es=0.6). Respectively, also daily smokers with any psychiatric disorder other than psychosis (n=1121) had higher scores in all SWAN domains: inattention (-7.0 vs. -2.1, p&lt;0.001, es=0.5); hyperactive-impulsive (-11.6 vs. -7.0, p&lt;0.001, es=0.5); and combined (-18.6 vs. 9.1, p&lt;0.001, es=0.5).
Within psychosis group, daily smoking associated only with inattention symptoms (standardized beta-coefficient (sbc)=0.38 p=0.004) in the multiple linear regression. Among those without psychiatric disorders, and among those with psychiatric disorders other than psychosis, daily smoking associated with all SWAN symptom domains. The respective figures were for inattention (sbc=0.14, p&lt;0.001; sbc=0.12, p=0.001); for hyperactive-impulsive (sbc=0.11, p&lt;0.001; sbc=0.12, p=0.001); and for combined (sbc=0.14, p&lt;0.001; sbc=0.13, p&lt;0.001).

Discussion
In adolescence, the relationship between inattention problems and daily smoking was remarkable among participants with subsequent psychotic disorder. Vulnerability to smoking among adolescents at risk for psychosis may be explained by self-medication related to inattention problems.

References