Abstract
Background: This study aimed to evaluate the efficacy and safety of Noofen((®)) (Phenibut) in patients with Adjustment Disorder (AjD) and to assess the usability of the ADNM-20 (Adjustment Disorder New Module 20-item questionnaire) in routine clinical practice. This is the first study of Noofen(®) in patients with AjD conducted in Latvia, and it also represents one of the first implementations of the ADNM-20 scale in routine clinical settings, where its applicability has not yet been widely established. Methods: A non-interventional observational study was conducted across several general practice offices in Latvia. Patients aged 18-70 with clinical symptoms of AjD, an ADNM-20 total score ≥ 30, and a new prescription for Noofen(®) 250 mg three times daily for at least three weeks (per routine practice) were included. Exclusion criteria ruled out concomitant psychiatric or severe somatic conditions and use of medications or interventions that could affect AjD symptoms. Patients completed the ADNM-20 before and after treatment, and score changes were evaluated. Results: Ninety patients (65 women, 25 men; mean age 48 ± 12 years) completed the study. At baseline, 56.7% had high AjD symptom severity, with work-related stressors most frequently reported as triggers. After three weeks of Noofen(®) treatment, ADNM-20 total scores decreased significantly (mean reduction 14.8 ± 11.3 points, p < 0.001), with greater improvement in core vs. accessory symptoms. Symptom severity shifted, with the proportion of high-severity patients decreasing 2.5-fold, and 14.4% scoring below the AjD diagnostic threshold post-treatment. Noofen(®) was well tolerated. ADNM-20 showed good sensitivity to symptom change but remained vulnerable to human error during scoring. Conclusions: Noofen(®) significantly reduced AjD symptoms, particularly sleep disturbance, restlessness, and anxiety, and was well tolerated. The ADNM-20 questionnaire proved useful in clinical practice and should be considered for routine use to better recognize and monitor AjD.