Depression is a relatively common occurrence in schizophrenia and is found in almost 60% of patients suffering from this disease. However, in the case of a bipolar course of depression, even if there are a number of signs of schizophrenia, the diagnosis of the latter may be questioned. In schizophrenia, the overall duration of depression is usually short relative to the total duration of the illness.
In 25–50% of patients, an acute attack of schizophrenia can manifest depressive symptoms. This is usually observed in simple forms of schizophrenia. Here, in the structure of depressive symptoms, hypochondria is often detected.
In most cases, depression makes itself felt after the cessation of an acute episode of psychosis and is most noticeable during the remission of schizophrenia. This phenomenon is detected in 25% of patients and is most often associated with a reaction to the disease, stigmatization and reduced quality of life.
The literature describes in sufficient detail the negative attitude towards reality in a patient with schizophrenia, which developed after the acute phase of the disease, because it is during this period that such an unusual world opens up for a sick person that “returning to Earth” becomes impossible.
The presence of psychogenic depression in many patients with schizophrenia and at the time of hospitalization due to the development of acute psychosis was revealed. In this case, the depression is due to the peculiarities of the personality, its reaction to the disease. It is assumed that depressive symptoms may be part of a schizophrenic process, and is not a personal response to this pathology or an independent disease.
With depression that has developed against the background of schizophrenia, a specific, difficult to express the words “dark emptiness, where there is no beginning or end” prevails. Symptoms of depression in schizophrenia show signs of apathy and a decrease in volitional activity.
The presence of depression in patients with schizophrenia, as a rule, is associated with an unfavorable prognosis for the course of the disease. Probably, depression in schizophrenia would be detected more often if the symptoms of the first were not masked by pronounced negative symptoms, impaired thinking and memory in the second. Depression in schizophrenia usually develops over a period of several weeks, and sometimes several years, either becoming aggravated or now extinct.
Many facts speak about the relationship between schizophrenia and depression: antipsychotics used to treat schizophrenia can provoke the development of a particular depression (“sedentary depression”) and even suicide.
Especially pronounced depressive states were noted during the treatment of schizophrenia with depot-neuroleptics. In this case, the patient’s condition was characterized by a slight restriction of movements, anergy, emotional lethargy, drowsiness (De Arlacon R., Carney M., 1969). Extrapyramidal symptoms developed during treatment with neuroleptics (reduced spontaneity of movements, apathy) can be difficult to differentiate from depression or manifestations of residual schizophrenia. Therapy of extrapyramidal symptoms with anticholinergic drugs helps to reduce the severity of symptoms of depression.
Supporters of psychoanalysis (M. Klein) suggested that the development of schizophrenia in adulthood contributes to the violation of protective mechanisms, and when the reduction of these disorders occurs, the patient can regress to the depressive phase. Clinically, depression after an acute attack of schizophrenia is a retarded depression with complaints of melancholy, lack of emotion, a decrease in the urge to communicate and the presence of pronounced thoughts of suicide.
An analysis of hemispheric connections showed that the lateral organization of the hemispheres determines the form of subsequent psychosis. So, in particular, the disorder of the function of the dominant left hemisphere leads to the occurrence of schizophrenia, a violation in the non-dominant right hemisphere causes the development of depression.
In healthy people, rational brain asymmetry is observed, in which the right hemisphere controls the inducing effect of the signals generated by the left hemisphere. The patient becomes more depressed if in his left hemisphere increases the severity of linguistic function. There is an increase in disorganization of the right hemisphere with contralateral suppression of the function of the left hemisphere by disrupting the transmission of impulses through the corpus callosum. Studies have shown that patients with schizophrenia demonstrate a pronounced left-sided asymmetry by psychological tests, while in depressions occurring during acute psychosis, right-sided hemisphere is more often detected. As a result, it was suggested that depression in schizophrenia can develop through two mechanisms: on a primary basis (in the right hemisphere) or in those patients with schizophrenia who have a fundamental deficiency in the dominant hemisphere – the left, followed by contralateral suppression.
In patients with schizophrenia, suicides are often observed. It is believed that about 10% of patients with schizophrenia commit suicide, and risk factors in this case are adolescence, male gender, the presence of a relapse of the disease, episodes of depression in the past, social isolation. It must be remembered that the high risk of suicide persists in patients with schizophrenia even after the release of acute psychosis.