It is all in the factors: effects of cognitive remediation on symptom dimensions

Cognitive remediation (CR) aims primarily to improve cognition and functional outcomes. However, a limited number of studies reported a positive effect on symptoms. This limited effect may be because the symptom clusters considered are too broad and heterogeneous. This study explores, for the first time, the effect of CR on five empirically defined symptom dimensions of schizophrenia.

Participants were patients with schizophrenia taking part in a randomised controlled trial comparing CR plus treatment as usual (CR, N=43) to treatment as usual (TAU, N=42). All participants were assessed at baseline and 14-weeks (i.e. at the conclusion of treatment for the CR group) with the Positive and Negative Symptoms Scale (PANSS). Five symptom dimensions were derived from the PANSS scores: Positive (POS), Negative (NEG), Disorganised (DIS), Excited (EXC) and Emotional Distressed (EMD).

After CR, the therapy group had a significant reduction in DIS and NEG symptom dimensions compared to the TAU group. The traditional PANSS factors showed no effect of CR on symptoms.

CR can have not only a positive effect on disorganisation but also on negative symptoms. Using detailed symptom dimensions can characterise more accurately the effect of CR on symptom of schizophrenia.