Trajectories of change within cognitive behavioral therapy for psychosis.

High variety in treatment responses is expectable in heterogenous patient groups, such as in individuals with psychosis receiving cognitive behavioral therapy (CBTp). However, knowledge about the diverse trajectories to improvement is limited. This study therefore aimed to detect subgroups of individuals with psychosis with different patterns of change and to identify the covariates associated with these different trajectories. We analyzed data from a sample of individuals with a psychotic disorder (N = 108) who had received CBTp in two German outpatient clinics. Session-by-session measures included general psychopathology to assess symptomatic response and a short version of a patient-reported outcome measure of psychological recovery assessing coping with distressing symptoms, emotions and situations. Growth mixture models were used to identify subgroups of individuals that differed in their trajectories of treatment responses within the first 25 sessions of treatment. For general psychopathology, three distinct trajectories (Symptomatic Response, 50.6%; Symptomatic Non-response, 39.6%; Symptomatic Rebound, 9.9%) and for psychological recovery, two distinct trajectories (Recovery Response, 67.6%; Recovery Non-response, 32.4%) were identified. Post hoc analyses revealed that 90% of those with a symptomatic response also belonged to the recovery response trajectory group. Higher psychotic symptom scores, lower functioning and longer duration of disorder were associated with the symptomatic rebound trajectory. The results underline the encouraging potential of identifying response patterns. The knowledge gained by this type of research can provide a basis for empirically-derived decision rules for clinicians working with this heterogeneous patient group.