Recent Research in Schizophrenia

Recent Research in Schizophrenia
By
Dr. David Mulhall

The nature of research in a field of Schizophrenia is there are studies ongoing throughout the world on a wide array of topics both on the cause of the illness looking at early history, genetics, the onset of the illness and review of treatment interventions both medication, psychosocial interventions that may be of benefit. Given that Schizophrenia is likely to have a multi factorial cause and a significant number of different gene markers suggesting vulnerability to the illness it is likely that we are dealing with a spectrum illness rather than one sharply defined illness with clear boundaries. In addition the development of new insights and knowledge is slow, gradual and incremental in type, thus there is no one single piece of research in the past few years which has “solved the problem”. There however have been ongoing advances and I will highlight a few of them. For further information readers are referred to the Early Psychosis Nova Scotia Program which may be accessed via the internet and has a significant amount of detail for those with Schizophrenia, their family and professionals involved in treatment.

The main medication interventions over the past forty years have been based on the belief that there is an imbalance in neurotransmitters. In illnesses such as depression the main neurotransmitter is Serotonin with psychotic illnesses such as Schizophrenia it is Dopamine. Street drugs which cause an increase in Dopamine such as amphetamines, cocaine and LSD can all cause drug induced psychoses. All medications thus far that have been used for the treatment of psychosis will reduce the level of Dopamine. Over the years the main thrust of medication intervention has been to develop medications that are effective in targeting specific areas in the brain with minimal effects on other areas of the brain which utilize Dopamine for other purposes. The original group of medications such as Chlorpromazine, Haloperidol were effective in treating positive symptoms but also caused marked problems with movement disorders. The newer medications such as Olanzepine cause significantly less movement problems, however the more recent group of medications have in general been associated with greater weight gain and unwanted metabolic affects, i.e. increased vulnerability to diabetes and elevated lipids. One of the latest medications available in Canada currently not funded in Nova Scotia is Ziprasidone (ZELDOX) which is an effective antipsychotic medication with minimal impact on weight and does not cause metabolic abnormalities. A more recent trend has been to look at other neurotransmitters. It is known that the Serotonin system has some role in psychosis and a newer “angle” is the role of Glutamate with alteration of these levels causing features of both positive and negative symptoms of Schizophrenia. A street drug Ketamine (Special K) has often caused people to present to the Emergency Room with illnesses that resemble Schizophrenia. It also causes exacerbation of symptoms of Schizophrenia in those with prior diagnosis. The importance of Glutamatergic transmission is underscored by recent report that a “mGLU2/3” agonist is effective by itself in treating the illness. This is the first successful treatment not directly based on Dopamine level alteration. At present this drug is in early stage of development but researchers are looking at other agents currently used in psychiatry such as Topiramate which has a “Glutamate type activity” to determine whether it would be of clinical
use.

Other areas of interest are looking at methods, community interventions that might help detect Psychosis sooner. There interventions when applied to “vulnerable populations”, i.e. those with family histories of illness, etc. showing some benefit but attempts to replicate the benefit in the general population have not bee successful.

There appears to be some early indication of benefit of the use of Omega 3 fatty acids in helping with recovering from Schizophrenia. It is important to understand that these agents are taken in addition to conventional treatment and not instead of.

Other areas of interest are looking at brain scans of those who have high risk for psychosis to determine whether you can predict who will develop the illness and who will not.

The role of lifestyle interventions to minimize the impact of weight gain, metabolic changes, etc., those on medication have also been assessed and require a significant amount of intervention and have had a modest benefit.

Other studies have looked at the level of functioning of those who then develop psychosis at a later stage and how it helps differentiate the outcome of first episode psychosis.

Finally there is ongoing concern about the vulnerability to psychosis in those using street drugs and the arguments about the increased potency of cannabis with some levels of THC being high in “SKUNK” a potent cannabis agent. It appears there is a sub group of adolescence who are vulnerable to these agents and development of an earlier onset of psychosis in addition significant risk of relapse in those who continue to use street drugs from an episode of psychosis.

This is a brief review of some of the fields of study which help in forming day to day care. Please check the Early Psychosis Nova Scotia internet site for further details and for new developments.