Motivational impairment could be early target for psychosis risk
medwireNews: Research suggests that motivational impairment may be present before psychosis onset but does not worsen over the course of the illness.
In fact, contrary to their hypothesis, the researchers found that motivational deficits were worse in patients at clinical high risk (CHR) of psychosis than in patients who had lived with the condition for many years.
Lead researcher Danielle Schlosser (University of California at San Francisco, USA) and team measured the anticipatory pleasure and consummatory pleasure of 60 CHR patients, using the Temporal Experience of Pleasure Scale. They found that both these measures were significantly reduced relative to those in 29 age-matched mentally healthy controls.
In addition, the CHR patients had significantly increased behavioural inhibition and reduced behavioural drive and reward responsivity on the Behavioral Inhibition Scale/Behavioral Activation Scale.
These differences may lead CHR patients to “avoid effort-related goals and to withdraw from perceived psycho-social challenges”, suggest the researchers.
“Both of these processes likely contribute to a failure to engage in growth-promoting socio-affective experiences and thus to increasing social isolation, rendering them even more vulnerable to heightened stress responsivity when facing the normal developmental challenges of adolescence”, they write in Schizophrenia Research.
“It is not difficult to conceive that such a vulnerable state increases the risk for onset of a first-episode of psychosis.”
By contrast, anticipatory and consummatory pleasure in 67 patients with recent-onset schizophrenia and 78 with chronic schizophrenia were not significantly different from that in controls. However, anticipatory pleasure was more impaired than consummatory pleasure in all three patient groups.
Schlosser and team found that increased anxiety was significantly associated with behavioural inhibition in all three patient groups, “suggesting that anxiety plays a key role in heightening sensitivity to punishing stimuli across the course of psychosis and may also represent an important therapeutic target.”
Depression was associated with reduced anticipatory pleasure, but only in CHR patients, leading the researchers to suggest that depression might be “a useful leverage point for early intervention”, saying: “For example, it is possible that alleviating depressive symptoms might enhance reward anticipation.”
They add: “Importantly, these leverage points may be responsive to straightforward behavioral treatments, which hopefully would provide long-lasting health-promoting effects.”
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2014
By Eleanor McDermid, Senior medwireNews Reporter