Background:
The aim of this study was to compare the risk for mental health disorders between smokers and non-smokers and to assess the risk for depression and anxiety according to addiction severity.

Methods:
This cross-sectional study assesses the mental health status and relationship with the severity of nicotine addiction in a sample of smokers admitted to Pamukkale University Hospital Smoking Cessation Clinic (n = 101) from 1 June 2012 to 31 August 2012 compared to a group of non-smokers from the general population (n = 101). We conducted semi-structured face-to-face interviews to collect sociodemographic data; we assessed the participants’ mental health status with the General Health Questionnaire-12 (GHQ-12) and the Hospital Anxiety and Depression Scale (HADS), and we measured nicotine addiction severity with the Fagerström Test.

Results:
The risk for mental illness reported by smokers based on the GHQ-12 was significantly higher than that for non-smokers (p = 0.001). The anxiety and depression scores according to HADS were higher among smokers (16.8% and 22.8%, respectively) than non-smokers (4.0% and 5.0%, respectively) (p = 0.006 and p = 0.001, respectively). The nicotine addiction severity was higher in smokers with higher anxiety and depression scores (p = 0.008).

Conclusions:
We found high scores for mental illness in treatment-seeking smokers compared with non-smokers. The risk for anxiety and depression was higher among smokers. Increased nicotine addiction severity was associated with increased risk for mental illness and increased scores of anxiety and depression.