Quality of life and functioning ability in subjects vulnerable to psychosis

It is well established that quality of life (QOL) and functioning ability are impaired in psychosis, especially schizophrenia. Little is known about QOL and functioning in subjects vulnerable to psychosis (VTP).

Three samples of nonpsychotic subjects (first-degree relatives of psychotic or severely ill patients, treatment-seeking patients, and a random community sample, in all 133 subjects) were assessed by the Structured Interview for Prodromal Symptoms and their vulnerability to psychosis was defined by severity of lifetime psychotic-like positive symptoms (nonsymptomatic, symptomatic, VTP). Quality of life was assessed by the Heinrichs' Quality of Life Scale and the Global Assessment of Functioning Ability (GAF) was used to measure functioning. Variance of QOL and GAF was explained by vulnerability status and psychiatric symptoms.

Quality of life and functioning ability decreased linearly as positive symptom intensity increased and was lowest in the VTP subjects when background factors were controlled for. In multivariate analysis, negative symptoms predicted low QOL/GAF scores in addition to vulnerability status that was based on positive symptoms.

Vulnerability to psychosis is associated with decreased QOL and impaired functioning ability. Although current diagnostic evaluation of patients at high risk of psychosis relies heavily on the occurrence of positive symptoms, negative symptoms seem to be strongly associated with QOL and functioning ability in VTP subjects. This should be taken into account when assessing putatively vulnerable patients and planning treatment interventions for them.