What causes schizophrenia?

The causes of schizophrenia are not clear. Stress and drugs such as cannabis and other risk factors can trigger symptoms of schizophrenia in some people. It can also run in families. The symptoms seem to indicate an imbalance in the actions of two brain chemicals: dopamine and serotonin. Scientists think that a malfunction of neurons in the brain areas that deal with emotions, memory and planning (the limbic system and frontal lobes) may be to blame. Scientists hope that identifying genes that predispose people to schizophrenia will help find treatments.

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PET scans of a schizophrenia sufferer's brain (left) and normal brain (right).

Can we treat schizophrenia?

Traditional antipsychotic drug treatments for schizophrenia block receptors for the neurotransmitter dopamine in the brain. They are effective in relieving hallucinations and delusions, but have little effect on other symptoms: lack of motivation, tiredness and depression. Newer drugs, which act at several receptor sites, including those for serotonin and dopamine, seem to be effective in treating these symptoms as well, and have fewer unpleasant side effects. Schizophrenia can also be successfully treated by a psychological therapy called cognitive behavioural therapy.

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Snakeroot is a natural source of reserpine, an antipsychotic, which has been used to treat schizophrenia.

Is schizophrenia inherited?

Although one in every hundred people in the general population will get schizophrenia at some point in their lives, this rises to one in ten for people with an affected parent, brother or sister, and one in two for those with an affected identical twin. Because identical twins share identical genes, other, non-genetic factors must also be involved. Scientists have located genes that are altered in schizophrenia, but do not yet understand how they interact with each other or with environmental factors.

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Principal Funder:

Wellcome trust

Major Sponsors:

GlaxoSmithKline life technologies