How Does Psychotic Depression Affect Mortality Risk Compared to Severe Non-Psychotic Depression?

What you need to know

• Psychotic depression is associated with a 60% higher risk of death over 5 years compared to severe non-psychotic depression
• The highest relative risk for those with psychotic depression was suicide, with over twice the risk compared to non-psychotic depression
• About 17% of people with psychotic depression were later diagnosed with schizoaffective disorder, bipolar disorder, or schizophrenia

Understanding Psychotic Depression

Depression is a common mental health condition that can range from mild to severe. In some cases, people with severe depression may also experience psychotic symptoms like delusions or hallucinations. This is known as psychotic depression.

While we know that depression in general is associated with increased health risks, less is known about how psychotic symptoms specifically impact long-term outcomes. This large study aimed to examine mortality rates for people diagnosed with psychotic depression compared to those with severe non-psychotic depression over an 18-year period.

Study Design and Participants

The researchers used nationwide health registers in Finland to identify adults aged 18-65 who were diagnosed with either psychotic depression or severe non-psychotic depression between 2000-2018. They excluded anyone who had pre-existing diagnoses of schizophrenia spectrum disorders or bipolar disorder.

This resulted in two groups:

• 19,064 people with psychotic depression
• 90,877 people with severe non-psychotic depression

The study then followed these individuals for up to 18 years to compare mortality rates and causes of death between the two groups.

Key Findings on Mortality Risk

Over the full 18-year follow-up period, 11% of those with psychotic depression died, compared to 7% of those with non-psychotic depression. After controlling for factors like age, gender, and other health conditions, the key findings were:

• 60% higher risk of death from any cause over 5 years for those with psychotic depression
• Over 2 times higher risk of death by suicide
• 63% higher risk of accidental death
• 62% higher risk of death from cardiovascular disease

The excess mortality risk was highest in the first year after diagnosis but remained elevated throughout the follow-up period. About half of all deaths occurred within the first 5 years after diagnosis in both groups.

Changes in Diagnosis Over Time

An important aspect the researchers examined was how many people initially diagnosed with depression later received other psychiatric diagnoses. They found that 17% of those with psychotic depression and 8% of those with non-psychotic depression were later diagnosed with either:

• Schizoaffective disorder
• Bipolar disorder
• Schizophrenia

For both groups, bipolar disorder was the most common new diagnosis. However, those initially diagnosed with psychotic depression were:

• 12 times more likely to be later diagnosed with schizoaffective disorder
• 6 times more likely to be diagnosed with schizophrenia
• 40% more likely to be diagnosed with bipolar disorder

Interestingly, for those with psychotic depression, receiving one of these new diagnoses was associated with lower mortality risk compared to those who did not have a diagnostic change. This suggests there may be subgroups within psychotic depression that have different long-term outcomes.

Impact of Other Mental Health Conditions

The researchers also looked at whether other mental health conditions could explain the higher mortality in psychotic depression. They found that people with psychotic depression were more likely to have pre-existing:

• Personality disorders
• Substance use disorders
• History of self-harm

However, even after controlling for these factors, the excess mortality risk remained for those with psychotic depression. This indicates that the psychotic symptoms themselves seem to be driving the increased risk, rather than these other conditions.

Implications for Treatment

These findings highlight the need for careful assessment, monitoring and treatment of people with severe depression, particularly those experiencing psychotic symptoms. Some key implications include:

• Clinicians should actively screen for and ask about psychotic symptoms in people with severe depression, as these can sometimes be missed
• The elevated suicide risk, especially in the first year, emphasizes the need for close monitoring and effective treatment early on
• Long-term follow-up is important, as excess mortality risk persists for many years
• A holistic treatment approach is needed to address both depressive and psychotic symptoms
• Further research is needed to better understand potential subgroups within psychotic depression that may have different outcomes

Limitations to Consider

While this was a large, long-term study, there are some limitations to keep in mind:

• It relied on diagnoses recorded in health registers, so some cases of psychotic depression may have been missed
• Information wasn’t available on all potential risk factors, like unemployment or social isolation
• The study couldn’t determine if people still had psychotic symptoms at the time of death

Conclusions

• Psychotic depression is associated with significantly higher mortality risk compared to severe non-psychotic depression, especially in the first 5 years after diagnosis
• The excess risk is not explained by other mental health conditions and appears to be driven by the psychotic symptoms themselves
• Close monitoring and effective treatment of both depressive and psychotic symptoms is crucial, especially in the early stages
• Further research is needed to identify potential subgroups and improve long-term outcomes for people with psychotic depression