Revision with unchanged content. Evidence supports the benefit of cognitive behavioral therapy (CBT) of psychosis for people experiencing psychotic symptoms, often diagnosed with schizophrenia. This study explores whether a mentored self-help intervention with similarities to CBT of psychosis benefits people experiencing psychotic symptoms and diagnosed with major mental disorders. A self-help workbook stemming from the British psychiatric survivor and voice hearers’ movements is used. Research results show significant between-group differences on the Brief Psychiatric Rating Scale subscale for Anxious Depression. While a conservative interpretation of this result is that it is due to chance, a more positive interpretation is that the mentored self-help intervention made an improvement in participant levels of depression-anxiety. If so, this supports further research on the intervention and is particularly important as over two-thirds of those diagnosed with schizophrenia experience a major depressive episode. This book is addressed to all mental health professionals who work with clients who hear voices. Mental health service users may also find it of interest.