At the recent 10th Biennial Congress of the Society of Psychiatrists of South Africa, Professor R. Emsley, head of the Department of Psychiatry at Stellenbosch University, presented a paper on the recent attention that has been given to the identification of co-morbid disorders in schizophrenia that may respond to particular therapeutic interventions.
The disorder schizophrenia consists of four distinct symptoms: positive, negative, cognitive and mood symptoms. It is this last category that Prof. Emsley considers in his paper. Depressive and anxiety symptoms have frequently been found to exist in schizophrenia. These symptoms can occur during any phase of the illness, and in many cases they may mimic the negative symptoms. This makes it particularly difficult to differentiate these symptoms from presenting schizophrenic symptoms. It has been found that between 7-70% of schizophrenics will show a prevelence for either depression or anxiety. Possible causes for the occurrence of these symptoms together with schizophrenia are varied, ranging from psychosocial explanations to substance abuse. It has also been suggested that schizophrenia may be found to be co-morbid with mood and anxiety disorders. Critics have challenged these views, and proposed instead that these symptoms are merely the core symptoms of the schizophrenic disorder itself. Nonetheless, these symptoms may have an additional negative effect on the social and vocational functioning of the afflicted. It has been shown that these depressive and anxiety symptoms will respond to therapeutic intervention, i.e. symptoms improved when patients were given any of the tricyclics, lithium, clozpine (Leponex), olanzapine (Zyprexa) or alprazolam (Xanor).
It was the above observations that led Prof. Emsley to study the frequency and severity of symptoms of anxiety and depression in patients in various stages of schizophrenia and assess their relationship to other symptoms of the illness and to treatment outcome. The study involved 195 psychiatric patients, who were undergoing anti-psychotic drug trials at Tygerberg Hospital over a 9 year period. The patients met DSM-IV criteria for either schizophrenia or schizphreniform disorder Various psychometric tests were used to determine whether the patients exhibited any symptoms of depression or anxiety. Depression and anxiety scores were compared in the following categories: first psychotic episode, acute psychotic relapse, treatment resistant patients and those with predominantly negative symptoms. Negative symptoms include symptoms that match the vegetative symptoms in depression, such as apathy, loss of interest, loss of concentration, etc. The researchers sought correlations between depression and anxiety scores and the following variables: positive symptom score, negative symptom score, composite scores and general psychopathology score.
The following results were obtained: among the psychiatric patients it was discovered that women experienced higher levels of depression and anxiety than men. Further, it was found that women had higher levels of affective symptoms (i.e. feeling sad or worthless), while men experienced higher levels of negative symptoms. Patients who were only experiencing a first episode of psychosis, were symptomatically different to patients who had suffered multiple episodes. For first episode patients, the experience of psychosis was terrifying, with patients requiring special care in dealing with the disorder. They experienced higher levels of depression and anxiety, a finding that must be taken into consideration when treating these patients. A high correlation between depression and anxiety and the positive symptoms of the disorder was reported,. This was a new finding, and one that was difficult to explain. It was proposed that the depressive and anxious symptoms were merely a manifestation of the same underlying disorder, i.e. they were both core symptoms of schizophrenia. Nonetheless, the overwhelming finding was the co-morbidity of depression and anxiety and schizophrenia. IT was also proposed that high levels of depression and anxiety, could possible predict a favourable outcome of the treatment of the schizophrenic patient, particularly if depressive symptoms are experienced during the acute phase of the schizophrenic episode.
The results of this study allowed Prof. Emsley to conclude that the identification of co-morbid depression and anxiety may enable clinicians to target patients with these symptoms of specific therapeutic intervention, thereby improving the overall outcome of the treatment process.