Some people who have severe clinical depression will also experience hallucinations and delusional thinking, the symptoms of psychosis.
Depression with psychosis is known as psychotic depression.
Symptoms of severe depression
Someone with severe clinical depression feels sad and hopeless for most of the day, practically every day, and has no interest in anything. Getting through the day feels almost impossible.
Other typical symptoms of severe depression are:
- fatigue (exhaustion)
- loss of pleasure in things
- disturbed sleep
- changes in appetite
- feeling worthless and guilty
- being unable to concentrate or being indecisive
- thoughts of death or suicide
Read more about the psychological, physical and social symptoms of clinical depression.
Symptoms of psychosis
Having moments of psychosis (psychotic episodes) means experiencing:
- delusions – thoughts or beliefs that are unlikely to be true
- hallucinations – hearing and, in some cases, feeling, smelling, seeing or tasting things that aren't there; hearing voices is a common hallucination
The delusions and hallucinations almost always reflect the person's deeply depressed mood – for example, they may become convinced they're to blame for something, or that they've committed a crime.
"Psychomotor agitation" is also common. This means not being able to relax or sit still, and constantly fidgeting.
At the other extreme, a person with psychotic depression may have "psychomotor retardation", where both their thoughts and physical movements slow down.
People with psychotic depression have an increased risk of thinking about suicide.
What causes psychotic depression?
The cause of psychotic depression isn't fully understood. It's known that there's no single cause of depression and it has many different triggers.
For some, stressful life events such as bereavement, divorce, serious illness or financial worries can be the cause.
Genes probably play a part, as severe depression can run in families, although it's not known why some people also develop psychosis.
Many people with psychotic depression will have experienced adversity in childhood, such as a traumatic event.
Read more about the causes of clinical depression.
Treating psychotic depression
Treatment for psychotic depression involves:
- medication – a combination of antipsychotics and antidepressants can help relieve the symptoms of psychosis
- psychological therapies – the one-to-one talking therapy cognitive behavioural therapy (CBT) has proved effective in helping some people with psychosis
- social support – support with social needs, such as education, employment or accommodation
The person may need to stay in hospital for a short period of time while they're receiving treatment.
Electroconvulsive therapy (ECT) may sometimes be recommended if the person has severe depression and other treatments, including antidepressants, haven't worked.
Treatment is usually effective, but follow-up appointments so that the person can be closely monitored are usually required.
Getting help for others
People with psychosis are often unaware that they're thinking and acting strangely.
As a result of this lack of insight, it's often down to the person's friends, relatives or carers to seek help for them.
If you're concerned about someone and think they may have psychosis, you could contact their social worker or community mental health nurse if they've previously been diagnosed with a mental health condition.
Contact the person's GP if this is the first time they've shown symptoms of psychosis.
If you think the person's symptoms are placing them or others at possible risk of harm you can:
The following websites provide further information and support: