Psychometric properties of the Greek version of Affective Lability Scale - Short Form (ALS-18) in a sample of adults with neurodevelopmental disorders.

Affect dysregulation refers to maladaptive patterns of emotional regulation that impair daily life functioning, common in many psychiatric disorders. It is expressed with the form of affective lability, an emotional construct composed of frequent and intense fluctuations in emotion in response to both pleasant and unpleasant events or the interpretations of events. The Affective Lability Scale (ALS) is a widely used self-reporting questionnaire that measures the tendency of emotions to shift from one to another as well as their tendency to oscillate between depression and elation and between depression and anxiety. The original scale had 54 items, but a shorter form of 18-items (ALS-18) was created, with three domains: anxiety-depression shift, depression-elation shift and anger shift. The aim of the present study was to evaluate the psychometric properties of the ALS-18 Greek version. The translation was conducted by two of the authors. The study took place in the 1st Department of Psychiatry of the National and Kapodistrian University of Athens, Eginition hospital. A sample of 108 adults was included in the survey in two groups, neurodevelopmental disorder group (attention deficit hyperactivity disorder or autism spectrum disorder) and controls. They all completed ALS-18, The State - Trait Anxiety Inventory (STAIT), Difficulties in Emotion Regulation Scale (DERS), The Hospital Anxiety and Depression Scale (HADS). The ALS-18 had satisfactory internal consistency; Cronbach's α value was 0.91 for the total scale and 0.89 for Anxiety/Depression, 0.86 for Depression/Elation and 0.85 for Anger. The three-factor structure was replicated in our data. The internal consistency reliability of all the ALS-18 factors in our study could be considered satisfactory with a Cronbach's alpha coefficient of 0.85 or above for all factors. Significantly higher mean values were found for all the subscales, Anxiety/Depression, Depression/Elation and Anger, in NDD subjects as compared to controls, showing good discriminative ability. The ALS factors discriminated well between clinical and non-clinical sample. The present study reveals that the Greek version of ALS-18 presents good psychometric properties, showing good internal consistency reliability as well as concurrent and discriminative validity. It has an elevated score in NDD and thus, our results indicate that affective lability could and maybe should, be a target integrated in therapeutic strategies.