Lack of motivation and cognitive impairments influence functional outcome in schizophrenia

Motivation, or lack thereof, affects performance. This well-known fact has been examined from a schizophrenic perspective in a recent study conducted by Dr. Gary Remington, a Psychiatry professor with the Faculty of Medicine at U of T, and his colleagues.

The purpose of the study was to investigate the relationship between specific clinical variables and functional outcomes in people with schizophrenia.

Published in the journal Acta Psychiatrica Scandinavica, this longitudinal study from the Centre for Addiction and Mental Health (CAMH) establishes both motivation and neurocognitive deficits as factors that independently contribute to functional impairment in schizophrenia.

Schizophrenia is a mental illness characterized by functional impairment. Gagan Fervaha, a PhD candicate at U of T is one of the co-authors of the study. According to him, functional impairment can be thought of as an extensive range of hindrances to functioning well as a member of society. Fervaha says these include impairments in self-care, living independently, social engagement, and occupational functioning. The symptoms of schizophrenia can be categorized into positive, negative, and cognitive.

Positive symptoms refer to thoughts and behaviors “added on” to an individual, such as hallucinations and delusions. These are the more commonly addressed and actively treated symptoms of schizophrenia.

On the other hand, negative symptoms indicate a “lack of” emotion, expression or motivation.

Cognitive symptoms involve an impaired ability to process information and make decisions, in addition to problems with attention and poor working memory.

A total of 754 participants between the ages of 18-65 took part in the year-long study. The diagnoses were based on the criteria for schizophrenia outlined in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), which defines standardized guidelines for mental health professionals. Participants’ functional outcomes were primarily measured using Heinrichs-Carpenter Quality of Life Scale (QLS), which is associated with objective functional milestones, such as employment and independent living. Researchers used two different approaches to measure functional outcome: a broad global measure that describes various aspects of functional impairments and a measurement of individual domains, such as deficits in participation in community activities, social relationships and occupational functioning.

“Both motivational deficits, deficits in initiation and persistence of goals, as well as cognitive deficits, which include impairments in memory and attention, were independently predictive of longitudinal functional outcome,” said Fervaha. He further explains that the ability of an individual to function in the community a year later is uniquely influenced by a combination of both motivational and cognitive deficits.

The results of this study suggest that amotivation and neurocognition impairment inhibit functional recovery in individuals with schizophrenia. Consequently, functional outcome can be improved by reducing these symptoms. It is interesting to note that positive symptoms do not significantly influence longitudinal functional outcome.

A different but related study also by Remington demonstrates the positive correlation between the two, suggesting that motivational impairment impacts cognition.

Further research on motivational and neurocognitive deficits can potentially lead to new approaches in making advances in treatment for schizophrenia. Currently, limited treatments, such as Cognitive Behavioral Therapy (CBT) and antipsychotics, focus on the positive symptoms of schizophrenia.

“Many people are able to live life effectively in the community, but some people struggle with daily living and among these people it is usually the motivational deficits that are impeding their ability to live the best that they can,” said Fervaha. He emphasized the importance of understanding both the psychological and neurobiological mechanisms underlying motivational deficits.

Motivation, or motivated behavior, is a broad concept and can be broken down into subcomponents, such as award evaluation and effort computation, which are mediated by different neuromechanisms.

“Understanding the neuromechanisms underlying motivational deficits, in particular the subcomponents of motivational deficits, allows intervention to improve outcomes for individuals,” said Fervaha.

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