Mental ill-health among young people has increased in the past decades in Sweden as well as in other western countries. When mental ill-health is connected with social vulnerability such as difficulties in completing education, unemployment or substance abuse you may be considered to have “complex needs”. This paper presents findings from a project (2016-2018) in two municipalities. The data consists of semi-structured interviews from two sub studies. One with 13 young persons (15-25 years) who have been or are recipients of long-term support from social services as well as psychiatric care, and one with 24 professionals from social services and psychiatric care. The aim is to investigate young people’s and professionals’ experiences of work practices aiming at increased well-being for young people labelled as having complex needs. The research questions are: What barriers for work practices for sustainable support are there from the young people’s perspective? How to overcome work practice barriers for giving sustainable support, from the professionals’ perspective? The questions are reflected in three themes; empowerment, relationships and collaboration. Barriers mentioned by the young people are high employee turnover as well as too many professionals involved in activities. Professionals might have their own ideas about what should be done, not taking the wishes of the young person into consideration to a satisfying level. In collaboration between different organizations, the professionals consider it important with at least one person who has the influence in several of them. To take the young person seriously as well as staying on in difficult times are considered important. We argue that the expression complex needs, when used as a way to categorize young people, may obscure that the problem also lies with highly specialized and complex welfare state organizations. They do not always succeed in catering for the interconnected needs of their clients.