This study aims to assess the behavioral as well cognitive changes in ADHD symptoms in terms of improvement of inhibitory control and attention in adults with ADHD

This study is a randomized double blind trial. After selection and enrollment, participants will be screened at baseline with a complete diagnostic and clinical assessment, and randomized to receive active or placebo t-PBM.

At visit 1 patients will undergo a (pre-treatment) neuropsychological testing followed by the first t-PBM session. After the first t-PBM session, the patients will undergo another (post-treatment) neuropsychological testing. After visit 1, which includes the first treatment, patients will receive additional 4 weeks of t-PBM treatments. After the last treatment, patients will come to clinic for undergo a clinical and neuropsychological assessment (visit 2). After the visit 2, patients will receive other 4 weeks of t-PBM treatments. After the last t-PBM treatment session, patients will come to clinic to undergo the final clinical and neuropsychological assessment (visit 3).

At the visits 1, 2 and 3 patients will be asked if they believe they received active or sham treatment.

Inclusion Criteria:

• subjects diagnosed with ADHD

Exclusion Criteria:

• schizophrenia or other psychosis
• current acute depressive episode
• bipolar disorder with current manic or depressive episode
• active substance use disorder
• autism
• dementia.