Evaluating a Workbook to Promote Autistic Wellbeing

Inclusion Criteria: * A pre-existing diagnosis of autism OR on a waiting list for autism assessment OR self-identified as autistic and scoring above cut-off on the autism quotient (AQ-50) screening questionnaire. * Aged 18 years or over and able to give informed consent to participate. * Under the care of a community-based mental health team in Kent and Medway Mental Health NHS Trust and not due for discharge during the study period. * Have already completed assessment processes (including risk assessment) during intake by the clinical team and a management plan is in place. * The named clinician assesses that the individual is in sufficiently stable condition to participate in the study, and is likely to remain engaged in the intervention. * Proficiency in reading and writing English. * If on medication for mental health, the dose is stable (minimum of 3 months) with no planned changes during the study. Exclusion Criteria: * Presence of a moderate to severe learning disability that would limit independent engagement with self-help materials. * Engaged in another psychological therapy or psychologically-informed intervention, or due to begin another during the study. * Current acute mental health crisis or elevated risk to self/others requiring intensive intervention (assessed via clinical team judgement). * Insufficient capacity to engage with the study protocol or complete measures (as determined by the care team).