Nicotine and alcohol dependence in patients with comorbid attention-deficit/hyperactivity disorder (ADHD)

Abstract

Aims: Several studies have shown that attention-deficit/hyperactivity disorder (ADHD) represents a significant risk factor for the onset and development of an addiction. Thirty-five per cent of adult ADHD patients are known to be addicted to alcohol. Many ADHD patients also have an increased nicotine consumption, which typically, leads to an improvement of attention, ability to concentrate and control of impulses. There may be pathophysiological connections here. On the other hand, it can also be assumed that there is a high prevalence of addicted patients with undiagnosed ADHD.

Methods: Ninety-one adult alcohol-dependent patients were examined for ADHD in this study, using the Wender Utah Rating Scale (WURS-k), Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) symptom check-list for ADHD and the Conners' Adult ADHD Rating Scales (CAARS, Long Version). The patients were divided into diagnostic sub-groups according to DSM-IV (inattentive type, impulsive type, combined type). Nicotine consumption was investigated using the Fagerström Test of Nicotine Dependence (FTND) and then graded as 'minimal', 'average' or 'high' nicotine dependence.

Results: There were 20.9% (WURS-k) or 23.1% (DSM-IV diagnostic criteria) of the patients addicted to alcohol, who showed evidence of ADHD in childhood. With the help of CAARS, it could be demonstrated that 33.3% of the patients who fulfilled the diagnostic criteria of ADHD, according to DSM-IV, had persisting ADHD in adulthood. The FTND showed a statistically significant difference in nicotine dependence between alcohol-dependent patients with and without ADHD in childhood. Patients numbering 76.2% with ADHD, demonstrated an 'average to high' level of nicotine dependence compared to 45.7% of those patients without ADHD. Furthermore, the number of patients not addicted to nicotine (19%) was significantly lower than among those without ADHD (36.6%) (P = 0.029).

Conclusions: The results of this investigation reveal that a large number of ADHD patients suffer from alcohol dependence, and an even greater number from excessive nicotine dependence. The outcome indicates that there are most likely pathophysiological connections with alcohol and nicotine dependence, and that this substance abuse is probably a form of 'self-medication'. The results clearly underline the great importance of early and adequate diagnosis and therapy of ADHD, in order to prevent exacerbation of addictive illness.