Anxiety and Depression are common in young people (CYP) and especially in CYP with a diagnosis of Autism. Autistic people often say therapy has not been adapted to meet their needs. A recent treatment called metacognitive therapy (MCT) is proving to be helpful, but the investigators do not know how autistic CYP will find MCT, or what changes to the delivery of therapy may be needed to meet their needs. This study hopes to explore whether MCT can help treat anxiety and/or depression in autistic young people. This study aims to offer five autistic CYP MCT. To take part, they must be between 11-16 years old and have depression and/or anxiety symptoms. The study will involve completing questionnaires at the start, during therapy, at the end and after 6 months. Therapy will be scheduled for at least eight sessions. Therapy involves working on what we think about our worry, rather than on specific worries. What we think about our worry can be positive or negative. For example, 'worrying helps me cope' and 'worrying could make me go mad'. This can affect where our attention goes and how we think. At the end of therapy, participants will be asked to take part in an interview about how they found the therapy. The questionnaires will help test how useful the measures are, suggest how helpful the therapy might be and whether benefits continue after the therapy has ended. Information will also be gathered through a post treatment interview about how the young people found the therapy. This will help understand whether any changes to the therapy are needed to meet the needs of autistic people. This information is necessary for planning a large-scale trial for autistic CYP. Such studies may improve treatment options and service provision for mental health problems in this population. Primary Question: • Is MCT a feasible and acceptable treatment for treating anxiety and depression in autistic CYP? Secondary Questions: * Is MCT associated with clinically significant change in outcome measures following the introduction of treatment for autistic CYP? * Are improvements associated with MCT maintained at 6 month follow up? * Are improvements associated with MCT replicable across autistic CYP? * Do the investigators need to modify how MCT is delivered to autistic CYP?