Differential performance of job skills in schizophrenia: An experimental analysis

Competitive employment is increasingly a goal for people with serious mental illness since it confers a key normative role to individuals in their efforts to achieve community integration, empowerment and recovery (Bond, et al., 2001; Liberman & Kopelowicz, 2005). However, estimated rates of competitive employment among individuals with schizophrenia range from 10-20% (Cook et al., 2005; Mueser, Salyers, & Mueser, 2001). Although supported employment has been successful in helping up to 40% of individuals with schizophrenia obtain competitive employment (Cook & Razzano, 2000; Lehman et al., 2002), half of them experience job terminations within the first six months of employment (McHugo, Drake, & Becker, 1998). Because the problem of early job termination is better described than understood, a priority for research in vocational rehabilitation of persons with schizophrenia is to identify the factors that impede job maintenance. Knowledge of those factors that are obstacles to employment is critical to designing improved methods of vocational rehabilitation for persons with schizophrenia. In general, barriers to sustained success at work are inherent in the mismatch between an individual's attributes, deficits, skills and interests on the one hand, and the properties, expectancies and requirements of the job on the other. One characteristic of individuals with schizophrenia that is relevant to successful person-job fit is deficiencies in cognitive capacities (Gold et al., 2002; McGurk & Mueser, 2003). Impaired cognition causes difficulties for persons with schizophrenia in performing many tasks that are found in the workplace. Moreover, well-replicated research has revealed a strong association between cognitive functions and success of schizophrenia patients on a wide variety of instrumental role activities including employment, social skills and social functioning (Green, Kern, Braff, & Mintz, 2000). The purpose of this study was to determine if the individuals' vocational success might be a function of the cognitive "demands" imposed by typical entry-level job tasks. Three such tasks were used in this study. One involved learning how to select and serially insert parts into a computer motherboard, which emphasizes visual-spatial memory skills; another involved sorting written material alphabetically and categorically, which makes a strong demand on verbal working memory; and the third involved learning the basic procedures of word processing using a personal computer, which taps verbal learning ability (Kern et al., 2002; Zarate, Liberman, Mintz, & Massel, 1998). The hypotheses were that clients would perform better on tasks that required less demands on verbal learning and memory, and that participants who received occupational therapy would do more poorly on the tasks than their counterparts who received specialized training for the tasks. Methods Design The three disparate entry-level work tasks were designed to be representative of entry-level jobs available in the community (Zarate, Liberman, Mintz, & Massel, 1998). Occupational Therapy (OT) was chosen as a comparative method because it was conducted in a manner to give structured opportunities for participants to improve their task-oriented attention, concentration and learning capacities and to give occupational therapists the occasion to prompt and reinforce participants for improved cognitive functioning and task productivity. In addition, OT was designed to serve as a control for the amount of interpersonal contact between participants and therapists. The same certified occupational therapists conducted both Work Training (WT) and OT in groups of 4-6 individuals. All participants performed each task, and they were evaluated on accuracy and productivity at baseline, immediately before training commenced 4 weeks later (week 4), and at weeks 12 and 24. Participants were randomly assigned to WT that consisted of training on each task over a two-week period or to OT that focused on crafts and other creative activities for the same time as participants in the WT condition. …