Feasibility and Efficacy of Cognitive-Behavioral Therapy for Patients With ADHD/Behavioral Addiction Comorbidity

Proportion of randomized present at the 12-week visit

Number of sessions performed between baseline and 12 weeks,

percentage of patients who attended at least 70% of sessions

Number of randomized patients / number of eligible patients eligible patients

only assessed in Cognitive-behavioural therapy group, assessed during an interview with a psychologist (qualitative evaluation)

only assessed in Cognitive-behavioural therapy group, assessed during an interview with a psychologist

only assessed in Cognitive-behavioural therapy group, assessed during an interview with a psychologist

Evaluated only for the control group, assessed during an interview with a psychologist

Evaluated only for the control group, assessed during an interview with a psychologist

Evaluation will be based on the ASRS-18 (Adult Self-Report Scale) total score. This self-administered questionnaire comprises eighteen questions, six of which are considered to be the most representative of the symptoms associated with ADHD. These six questions, in Part A of the questionnaire, form the core of the ASRS v1.1 screening. Part B contains the remaining twelve questions. The impact of symptoms on different areas of the patient's life is also assessed. Screening is positive when the patient presents at least 4 symptoms with a significant impact among the first 6 items . Each item is rated from 0 to 4, giving a total ASRS-18 score ranging from 0 to 72, with sub-scores for inattention (0 to 36), motor hyperactivity/impulsivity (0 to 20) and verbal hyperactivity/impulsivity (0 to 16).

The Adult ADHD Quality of Life scale (AAQOL) will be used during the assessment phases. This tool has good psychometric qualities and assesses four dimensions of quality of life: productivity in daily life, psychological health, relationships and outlook on life. The AAQOL provides a total quality of life score, as well as 4 sub-scores for each dimension. The total score is between 0 and 100, the sub-dimension scores between 0 and 100 (transformed from responses to each of the responses to each of the 29 items ranging from 1 to 5). The higher the score (total and sub-score), the higher, the better the quality of life

The Weiss Functional Impairment Rating Scale-Self-Report (WFIRS-S) will be used during the assessment phases. This tool, with good psychometric qualities, assesses the impacts of ADHD in seven domains: family, work life, school life, life skills, self-image, social life and risk-taking. Any item rated "2" or "3" is two standard deviations outside the clinical norms for ADHD and is considered impaired. A conservative threshold for defining impairment in any domain is either two items scored '2', or one item scored '3'. The average item score for most domains is '1', with the exception of 'at-risk activities', which is '0.5'. The average score for each of the 7 dimensions is between 0 and 3.

A visual analog scale (VAS) to assess craving will be used. In the absence of a validated tool to measure craving in a homogeneous way in behavioral addictions, we will ask participants to rate the intensity of craving on a scale from 0 to 10 (0 corresponding to no craving and 10 to maximum craving) and to evaluate the frequency of craving as well as its duration. This type of craving measurement is frequently used in the literature and in addiction research protocols.

The Impulsive Behavior Scale (UPPS-P) will be used during the assessment phases to measure impulsivity. This tool has good psychometric qualities and measures the following sub-dimensions of impulsivity: positive urgency, negative urgency, lack of premeditation, lack of perseverance and sensation seeking. The score for each dimension ranges from 4 to 16; there is no total score. The higher the score (subscales), the higher the impulsivity.

The Difficulties in Emotion Regulation Scale (DERS 36) will be used (during the assessment phases) to evaluate emotional dysregulation. With good psychometric qualities, this scale measures 6 dimensions: unacceptance of negative emotions, difficulty engaging in goal-directed behaviors in the presence of negative emotions, difficulty controlling impulsive behaviors in the presence of negative emotions, restricted access to emotion regulation strategies perceived as effective, emotional awareness and lack of understanding of one's emotions, defined as a lack of emotional clarity. The total score ranges from 36 to 180, with sub-dimensions scores ranging from 6 to 30. The higher the score (total scale and subscales), the greater the emotional dysregulation.

The Hospital Anxiety and Depression scale (HAD) will be used to assess the presence of anxiety and depressive symptoms in participants. This is a variable we wish to control for, in order to verify that anxiety and depressive symptoms are not potential confounding factors in the assessment results. This scale has good psychometric qualities and can be used to assess two dimensions: anxiety symptoms and depressive symptoms. The total score ranges from 0 to 21 for each dimension. For each dimension, the following interpretation can be proposed:

• 7 or less: no symptoms - 8 to 10: moderate score - 11 to 14: average score 15 to 21: severe score. In practice, a threshold score ≥ 11 for each subscale is retained for a significant anxiety or depression score.

Evaluation will be based on MINI-S interview (mini international neuropsychiatric interview, simplified )

Evaluation will be based on Clinical Global Impression. The CGI includes two complementary single-item measures that assess the following:

(a) severity of psychopathology on a scale of 1 to 7 and (b) change from baseline on a similar treatment on a similar seven-point scale. Following a assessment, the CGI can be completed in less than a minute by an experienced experienced assessor. The CGI is used to gather clinical impressions and track clinical clinical progress over time