Objectives Adolescence represents a significant period of vulnerability for the development of depression. Whilst research has begun to explore factors associated with the development, maintenance and outcomes of adolescent depression, there is little research investigating this experience from a parental viewpoint. The aim of this study was to explore mothers’ experiences of having an adolescent child with depression. Methods Eight mothers of depressed adolescents were recruited following their child’s clinical assessment at a Child and Adolescent Mental Health Service and participated in semi-structured interviews. The transcripts of the interviews were analysed using interpretative phenomenological analysis. Results The analysis revealed five interlinked superordinate themes: Finding a reason, something to blame; Living with uncertainty; Feelings of helplessness and frustration; Depression causes change; Hiding own emotions and needs. A key finding across the themes was the emotional distress and sense of uncertainty experienced by the mothers. Conclusions The findings highlight avenues for clinical practice and further research including exploring the type and format of information and support that parents would value most, the views of fathers, and more in-depth exploration of the identified themes with parents using both qualitative and quantitative methods.