The purpose of this uncontrolled pilot study is to develop and make an initial evaluation of a new treatment manual for treatment of ADHD in adults. The objectives in the treatment is to build relational skills, skills in organizing and structuring everyday life, handle difficult emotions and impulses etc. The treatment will be in a group format and it is hypothesized that the psychological intervention will result in reduced ADHD symptoms and to decreased experience of stress and depressive symptoms. The uncontrolled design does not allow for any causal inferences from the results, this pilot study is primarily to be seen as a preparation before a subsequent RCT.

Approximately one-third of children with ADHD continue to be fully symptomatic into adulthood and many of the remainders often retain some residual problems that require treatment. Thus ADHD is a prevalent and chronic disabling disorder. Drugs provide first line treatment for adults with ADHD but are not enough for everybody, while we still lack proper evidence for promising psychological treatment. In addition to core symptoms of ADHD including regulatory difficulties of attention, activity level and impulses, difficulties with emotional regulation are common.

Follow-up studies of adults with ADHD have shown that only a few patients were offered sufficient treatment and support after the neuropsychiatric assessment and testing. The majority of adults diagnosed with ADHD are offered pharmacological treatment (stimulant medication) as the sole treatment. However, stimulant medication is not effective for up to 20-50 percent of adults as they may not experience symptom reduction or they are unable to tolerate the medication.

Consequently, the possible benefits of identifying and treating individuals with ADHD are extensive. Treatment of ADHD is preferably multimodal, i.e. consisting of more than one intervention.

There has been limited research to date concerning psychosocial treatments for adult ADHD. Studies of cognitive behavioral therapy (CBT) and dialectical behavior therapy (DBT) show that structured short-term therapies are promising in reducing ADHD related symptoms and increasing life quality. Focus in the CBT treatment is to build skills, increasing and compensating for deficits in the executive functioning due to impairments of the frontal lobe. DBT combines change-oriented skills from CBT with acceptance-oriented skills and core mindfulness skills. DBT skills have been tried out and validated as a promising intervention package for adults with ADHD through the research of Steven Safren and Bernd Hesslinger.

The objective of the planned study is to evaluate a new manual for group treatment, with a combination of treatment methods from Safrens and Hesslingers evidence-based treatment manuals. The aim of the pilot project is to create a clinically effective combination of the different methods of treatment, with a high degree of understanding, acceptance, use and perceived usefulness of the patients undergoing treatment. Both qualitative and quantitative data about patients' perceptions and use of the different methods will be collected during and after treatment to increase knowledge of how treatments can be developed and combined in order to better match the needs of patients.

Inclusion Criteria:

1. * Clinical diagnosis of AD/HD

2. * Age 18-65

3. 17 or more on the Adult ADHD Self Report Scale (ASRS v1.1)

4. Not medically treated for adhd symptoms, or medically treated with central stimulants or comparable substance since at least one month with no significant changes in dosage and where no change in medical treatment is anticipated during the study time frame for the participant.

5. No change in any other medical treatment is anticipated during the study time frame for the participant.

6. Participant are by investigators considered able to follow through the training protocol and take part in measures taken during the study time frame

7. The participant hasn´t used drugs the last 3 months.

   Exclusion Criteria:

8. Diagnosed substance abuse according to DSM-IV criteria within 3 months prior to screening. Earlier episodic substance abuse is not excluding

9. Co-existing psychiatric condition that investigators believe will unable the participant to follow through the training protocol and take part in measures taken during the study time frame.

10. IQ ≤70 according to a neuropsychological assessment

11. * Suicidality risk which is assessed during the first assessment interview.

12. Organic brain syndrome

13. Serious somatic condition which will unable the participant to participate (through the training protocol)or, is anticipated to have a negative impact on the treatment results

14. Autism spectrum disorder (severe)

15. Severe depression

16. Other current psychological treatment for AD/HD