MedWire News: Young people with schizophrenia show abnormal brain development compared with their mentally healthy counterparts, study results show.

The findings indicate that in some people, schizophrenia may be caused, at least in part, by abnormal brain development during adolescence and young adulthood, when the brain is eliminating some connections between cells as a normal part of maturation, say the researchers.

The results also show that changes in brain development which can lead to schizophrenia are not limited to very early childhood, but also occur in adolescence and young adulthood - the age when schizophrenia symptoms usually start to appear.

Dr T Cannon, from the University of California in Los Angeles, USA, and team performed brain imaging scans on 16 participants, aged between 17 and 30 years, with recent-onset schizophrenia and 14 mentally healthy people in the same age range. Scans were then repeated two years later to identify any brain changes.

The researchers found that both groups of participants showed the usual loss of brain volume - an indication that the expected normal tissue loss was taking place.

However, compared with the mentally healthy participants, those with schizophrenia showed more tissue loss in a brain area called the prefrontal lobe, which controls functions such as judgment and memory. These brain functions are typically impaired in people with schizophrenia.

The team also found that participants with schizophrenia also showed more tissue loss in the parietal lobes, which help process sensory information. Abnormal sensory perceptions, such as hallucinations, are common in people with schizophrenia.

Overall, participants with schizophrenia had 1.6 times more tissue loss in these brain areas due to excess 'synaptic pruning' than the other participants.

"We have shown that brain changes occurring during the early stages of schizophrenia resemble an exaggerated normal anatomical pattern," Dr Cannon and team write in the journal Molecular Psychiatry.

They add: "It is conceivable that with deepened understanding of the mechanisms underlying brain volume loss, novel therapeutic and preventive strategies targeting these mechanisms can be developed to arrest the progression of the illness immediately following or even before the onset of psychosis."