Schizophrenia Part 2

Causes

While the exact cause of schizophrenia is not known. There is evidence that the balance of some brain chemicals (eg. dopamine) is altered which means that the messages from the brain do not pass correctly. There is a genetic influence meaning that it does tend to run in families; 70% of the risk of schizophrenia is thought to be hereditary. For example, a close family member (child, brother, sister, parent) of someone with schizophrenia has a 10% chance of also developing the condition. This is 10 times the normal chance.

Various triggers are also thought to cause it in people genetically prone to it. Triggers can include stress such as relationship problems, separation from family when a child, social isolation and bereavement; Viral infection during the mother's pregnancy, or in early childhood may be a cause; Brain injury during birth may be a cause in some people; Illegal or street drugs can be a trigger. Those who use cannabis heavily are six times more likely to develop schizophrenia than nonusers. Many other drugs of abuse such as amphetamines, cocaine and lysergic acid diethylamide (LSD) can trigger a schizophrenia-like illness.

Other conditions that can be confused with schizophrenia

Bipolar disorder and depression can also cause psychotic type symptoms which can lead to misdiagnosis of schizophrenia. On the flip side, schizophrenia can be misdiagnosed as bipolar disorder or depression, especially when negative symptoms predominate (negative symptoms were discussed in last week’s Westmeath Topic).

Delirium can have features that are like the positive symptoms of schizophrenia (e.g., hallucinations, delusions). Delirium is a confused state that is brought on by medical illness. The main feature that distinguishes schizophrenia from delirium is the timing. Symptoms of schizophrenia generally develop over weeks or months, whereas delirium usually develop quite rapidly and is mostly associated with medical illnesses. Delirium tends to be a lot shorter lasting than schizophrenia.

Some illnesses can cause symptoms similar to schizophrenia. These include hypoglycaemia (low blood sugar), hepatic encephalopathy (worsening brain function due to liver failure), electrolyte abnormalities such as hyponatraemia (low sodium levels), hypercalcaemia (raised calcium levels), hypocalcaemia (low calcium levels), hypomagnesaemia (low magnesium levels) and sepsis (severe infection). The symptoms resolve once the condition is controlled.

Some prescription medication can cause schizophrenia like symptoms. Examples of drugs that can cause schizophrenia like symptoms include anticholinergics (used to treat various conditions including urinary incontinence, COPD and allergies), benzodiazepines (for anxiety and insomnia), digoxin (for cardiac arrhythmias), phenytoin (for epilepsy), steroids (for inflammatory) and opioid analgesics (for severe pain). These drugs are safe in most patients when prescribed appropriately and psychotic type symptoms only occur in exceptional situations; for example, when they interact with other drugs or if the patient has a medical illness which causes the effect of the medication to be exaggerated.

Treatment

Often people suffering from schizophrenia do not realise they have a mental illness. They may not think they need help because the condition makes you believe the delusions or hallucinations are real. Therefore, it is often up to family and friends to seek treatment.

The causes of schizophrenia are still unknown; therefore, treatment focuses on eliminating the symptoms of the disease. While medication is not the only treatment option for schizophrenia, medication forms a major component of the treatment regime. Antipsychotics are mainly used to treat schizophrenia. They work by altering the balance of some neurotransmitters in the brain thus controlling symptoms.  Positive symptoms respond well to antipsychotic drugs however they do not work as well on negative symptoms. Antipsychotic medication is usually taken on a long-term basis to prevent relapses. Antipsychotic drugs are broadly divided into two categories; typical or atypical antipsychotics.

Older typical antipsychotics

These are sometimes called first generation antipsychotics and were the first type of antipsychotics developed in the 1950s for psychosis, especially schizophrenia. Examples include chlorpromazine (Largactil^®), trifluoperazine (Stelazine^®), haloperidol (Serenace^®), flupentixol (Depixol^® Injection, Fluanxol^® tablets), zuclopenthixol (Clopixol^® Injection), and sulpiride (Dolmatil^®). 30% of patients have a relapse during treatment with first-generation antipsychotic drugs compared with 80% without treatment.

Newer or atypical antipsychotics

These were first introduced in the 1990’s and are also known as second generation antipsychotics. Examples are amisulpride (Solian^®), aripiprazole (Abilify^®), clozapine (Clozaril^®), olanzapine (Zyprexa^®), quetiapine (Seroquel^®) and risperidone (Risperdal^®). There are now generic equivalents of most of these drugs now available; you can ask your pharmacist for an equally effective but less expensive version of your medicine. Because they demonstrate good balance between chance of success and the risk of side-effects, atypical are usually the first-choice treatment option for schizophrenia. However, for people already stabilised on typical antipsychotic there is no need to change to a newer one.

Depot injections of an antipsychotic drug

In some cases, an injection of a long-acting antipsychotic drug is used once symptoms have eased. The drug from a depot injection is slowly released into the body and is given every 2 to 4 weeks. The main advantage is that it prevents non-compliance which is when people forget to take their medication or decide not to take their medication. Not taking prescribed medication can be a problem with schizophrenia as the person often does not realise they have a problem or do not feel that they are ill. An American study showed that 74% of patients with schizophrenia discontinued medication within 18 months without consulting with their doctor leading to relapses. Depot injections prevent this problem and are administered by a trained nurse usually through the local community mental health service.

To be continued …. next week

Disclaimer: This article is meant to give a general overview of the topic discussed; for more specific and detailed information, please speak to a health care professional

Whelehans Pharmacy, Pearse Street and Clonmore, Mullingar. Tel 04493 34591. Eamonn’s full comprehensive article on schizophrenia is available in Whelehans on request or check www.whelehans.ie. Simply ask our staff for a free copy. References are also available upon request