“…Premorbid dysfunction is strongly associated with postonset illness characteristics including severity of negative symptoms, cognitive deficits, motor slowing, and treatment refraction (e.g., Addington, van Mastrigt, & Addington, 2003; Haim, Rabinowitz, & Bromet, 2006; Larsen, McGlashan, Johannessen, & Vibe-Hansen, 1996; Levitt, O'Donnell, McCarley, Nestor, & Shenton, 1996; Silverstein, Mavrolefteros, & Turnbull, 2003). Furthermore, a history of poor functioning in childhood and adolescence in nonpsychotic adult relatives of schizophrenia patients (Shapiro et al, 2009; Walshe et al, 2007), including monozygotic twins (Picchioni et al, 2010), suggests a genetic component to this association.…”