“…However, studies suggest that patients with dual diagnosis often receive insufficient treatment (Back et al , 2009; Carrà et al , 2015; Drake and Mueser, 2000; Sorsa et al , 2017). A consistent finding in the literature is that mental health professionals often find their competencies inadequate to provide dual diagnosis treatment which makes it challenging to treat the patient group (Back et al , 2009; Barry et al , 2002; Cleary et al , 2009; Griffin et al , 2008; Sorsa et al , 2017). Insufficient knowledge of dual diagnosis treatment and insufficient clinical skills have been associated with negative attitudes towards patients with dual diagnosis (Adams, 2008; Richmond and Foster, 2003), which can impede the treatment (Sorsa et al , 2017; Todd et al , 2002; van Boekel et al , 2013).…”