[Effectiveness of medical treatment in the adult ADHD unit of Landspitali 2015-2017].

Background: Attention deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder among children but symptoms may persist into adulthood. At Landspitali - the National University Hospital an interdisciplinary unit is responsible for ADHD-diagnosis and for commencing treatment of adult ADHD. The aim of this study is to evaluate the effectiveness of pharmaceu-tical treatment provided by the unit and the effects of psychiatric comorbidities.

Methods: The study is retrospective and includes all individuals ≥18 years of age who received pharmaceutical treatment in the adult ADHD unit at Landspitali 2015-2017. Individuals who had previously received treatment by the unit or were already on medication for ADHD were excluded. Information on symptoms and wellbeing before and after treatment were obtained from three questionnaires, an ADHD rating scale, DASS and QOLS.

Results: Of 211 patients who met inclusion criteria 144 (68%) completed the treatment provided by the unit on average 143 days. Impulsivity/hyperactivity predicted treatment failure with OR=0.96 (p=0.015). There was a statistically significant difference in all key response variables before and after pharmaceutical treatment (p<0.001). The Cohen's d effect size for ADHD variables were 3.18 for attention-deficit and 1.40 for impulsivity/hyperactivity. The effect size for quality of life was 1.00 and among the DASS subscales the maximum effect size was 1.43 for stress. Increased quality of life correlated with decreased symptoms as rated by DASS and the ADHD rating scale. Treatment success rates were significantly -higher for DASS but not for attention-deficit, impulsivity/hyperactivity and quality of life among individuals with psychiatric comorbidities alongside ADHD. Gender did not affect treatment effectiveness.

Conclusions: Those who complete treatment within the ADHD unit achieve good results with decreased psychiatric symptoms and improved quality of life. Treatment discontinuation is a challenge.