Psychosocial and cognitive rehabilitation of patients with solvent-induced chronic toxic encephalopathy: a randomised controlled study.

Background: There is little experience with the (neuro) psychological treatment of patients with solvent-induced chronic toxic encephalopathy (CSE). In this randomised controlled trial (RCT), a treatment programme was evaluated based on previous outcome studies of patients with chronic fatigue, whiplash and traumatic brain damage.

Methods: The treatment consisted of 8 group sessions based on cognitive behavioural principles focusing on inadequate illness behaviours, and 8 sessions of cognitive strategy training to compensate memory problems. The research design was an RCT with follow-up, comparing the cumulative effect of the 2 interventions allocated in random order with a waiting-list control group. Outcome measures were treatment satisfaction, self-ratings of psychosocial and cognitive changes, psychosocial and memory questionnaires and neuropsychological tests. Multiple linear regression analyses were performed with baseline scores, treatment versus control condition, effort status, and litigation or financial compensation status as predictors.

Results: Ninety-five patients started treatment, 84 patients had complete data. Treatment satisfaction was high. After the treatment, only the treatment group had improved on objective memory tests and on complaints related to CSE, but not on other questionnaires. Treatment effects diminished at follow-up. Insufficient effort and litigation were negatively associated with treatment outcome.

Conclusions: The positive treatment effects on the cognitive tests were only temporary. It might be important to study the effect of booster sessions to update practiced cognitive strategies. Effort was an important predictor of success, more important than involvement in a litigation procedure. This finding should have implications for the selection of patients.