Depression and psychosis can be combined with each other. This has been known since the days of Galen, who observed patients with a combination of depression and delusional judgments. The modern international classification of mental disorders has separated schizophrenia and bipolar disorder with an affective component into separate headings.
Patients with depression with a history of psychosis have a good prognosis. And patients with schizophrenia have a poor prognosis and dependence on the use of antipsychotic drugs. Patients with schizophrenia have long-term depressive conditions, which are caused, among other things, by the diagnosis of schizophrenia. Patients with depression with elements of psychosis have a history of long periods of depression. In classic depression, there may be negative thoughts, low mood, hallucinations, delusions that are not associated with an emotional state.
With depression, delusional judgments can be associated with stress factors, loss of work, a loved one, loneliness.
In some depressive conditions, hypochondria, hallucinations, somatic delusions are observed , which affects behavior. Patients can endlessly refine their diagnoses, look for pathology of internal organs for many years. Depression can be accompanied by delusions of persecution and irrational fears.
Depressive syndrome is sometimes combined with negative signs of schizophrenia (decreased motivation, social loneliness, flattened affect, anhedonia ).
Antipsychotic drugs used to treat schizophrenia can reduce motivation, neutralizing reward responses to stimuli. It is therefore very difficult to distinguish between depression in schizophrenia and primary depressive disorder.
At first glance, the clinical manifestations of psychosis and depression are different. But, there is evidence that these diseases have a common cause and pathogenesis. There is evidence of the involvement of the same genes in the development of schizophrenia, depression and bipolar disorder, ADHD, autism. Defects in the DISC1 gene lead to both depression and schizophrenia. There is evidence that the same genes are responsible for the development of schizophrenia, bipolar disorder, and depression.