What is the link between psoriatic arthritis and depression?
Psoriatic disease can have a significant impact on mental health and well-being. This may partly be due to social factors, the stress of living with a chronic condition, fatigue, and inflammation in the body. Research has linked inflammation to both psoriasis and depression.
This article outlines the causes of depression among people with psoriatic arthritis (PsA), as well as information on treating and coping with depression.
What is the link between PsA and depression?
The following factors can contribute to the development of depression in people with PsA.
Social stigma and low self-esteem
A person may have feelings of low self-esteem during a flare-up.
During a flare-up, a person with PsA may develop skin lesions or plaques. Some people may feel anxious about these symptoms, and this can contribute to feelings of low self-esteem, isolation, and loneliness.
Conversely, a person can experience pain and swelling without the skin flares of psoriasis, which means that it can be an invisible illness.
If a person has no visible symptoms, they may feel that their friends, family, or colleagues do not take their illness seriously, or that they underestimate their pain. This can be frustrating and upsetting.
Reduced quality of life
People with PsA may experience a range of physical symptoms, such as chronic pain, fatigue, and reduced mobility.
These symptoms can make it difficult for a person to carry out their daily activities, resulting in a reduced quality of life (QoL).
A 2014 study looked at the mental health of 306 people with PsA and 135 people with psoriasis but not PsA. The authors report that depression and anxiety were more common among people with PsA than among those with psoriasis alone.
In this study, several factors linked to QoL played a role in the development of depression. These included disease activity, pain, fatigue, and disability.
Fatigue and sleep disorders
Fatigue and sleep disorders are both risk factors for depression. They are also common symptoms of PsA.
A 2017 study looked at the relationship between PsA, sleep quality, and mental health. Researchers spoke to 41 people with PsA and 38 people without PsA.
Those with PsA reported more severe sleep disturbances. Sleep disturbance was especially linked with pain, inflammation, anxiety, and reduced QoL.
People with PsA and other chronic inflammatory diseases tend to have higher levels of pro-inflammatory cytokines. These cytokines can trigger inflammation in the body.
Recent research shows that elevated levels of inflammatory cytokines may also contribute to depression. Specifically, these cytokines reduce the availability of the following three key chemical messengers in the brain:
- Serotonin. Sometimes called the "happy chemical," serotonin plays a role in regulating mood. Serotonin is usually associated with elevated mood and feelings of well-being.
- Dopamine. Dopamine is a hormone that plays a role in motivation and pleasure.
- Norepinephrine. Norepinephrine helps regulate emotion.
Having low levels of any of these chemical messengers can contribute to low mood and depression.
For some people, PsA can cause considerable emotional distress. Stress is a known trigger for both psoriasis flares and depression.
When a person is stressed, their brain releases chemical messengers. Some of these can affect the immune cells.
Through a complex chain of events, these immune cells increase levels of inflammatory cytokines in the brain. The cytokines can, in turn, trigger inflammation and depression.
This process sets up a feedback loop, wherein stress causes inflammation and inflammation causes more stress.
Low levels of vitamin D
Most people recognise vitamin D for its role in maintaining healthy skin and bones. However, recent research suggests that vitamin D may also be important for staving off depression.
One 2013 study compared vitamin D levels among three groups of people: 1,102 adults with current depression, 790 adults with a history of depression, and a control group of 494 adults who had never experienced depression.
Compared with people with no history of depression, those with current depression had lower levels of vitamin D. Also, those with the most severe symptoms of depression had the lowest levels of vitamin D.
The researchers say that vitamin D deficiency may increase the risk of depression.
Although these studies suggest a possible link between PsA, vitamin D, and depression, no study has yet looked at a direct link between these factors.
Treatment and coping strategies
The following treatments and coping strategies may help people with PsA prevent or overcome any feelings of depression:
Doctors often recommend talking therapies, or psychotherapy, to treat depression.
A therapist who specializes in chronic conditions can help people come to terms with their diagnosis and learn strategies for coping when things get tough.
Talking to others with PsA
The National Psoriasis Foundation (NPF) offer a one-to-one mentoring program that helps people with PsA connect with one another.
By talking to other people with PsA, a person can get emotional support from someone else who understands what they are going through.
Support groups allow people with PsA to share their experiences of living with the condition. People can find support groups and chatrooms online.
There are also local support groups for people with PsA or other chronic conditions. Meeting in person can help combat feelings of isolation.
Exercising helps keep the joints flexible and mobile, and it also releases brain chemicals called endorphins, which can boost mood.
These combine exercise with relaxation techniques to help relieve both stress and physical symptoms.
Vitamin D supplements
Vitamin D supplements can help with psoriasis symptoms.
According to a 2016 review, there is currently not enough evidence to confirm that taking vitamin D supplements reduces depression.
To date, most participants who have taken part in these studies have had low levels of depression and adequate levels of vitamin D.
However, one review study suggests that taking vitamin D pills and applying skin creams can reduce the severity of psoriasis symptoms. For many people, simply reducing psoriasis symptoms may help alleviate stress and depression.
Doctors often use biologic drugs to treat PsA. These aim to treat the underlying disease by targeting specific parts of the immune system.
Before using biologics, around 20% of the study participants took antidepressants. After 2 years, there was a 40% reduction in using antidepressants. It is worth noting that the researchers did not directly measure the participants' mood.
Scientists need to do more research, including randomized controlled trials, to work out whether taking biologics can relieve depression in people with PsA. This research is already underway.
In fact, a 2015 review reports that some biologics may reduce symptoms of depression in people with moderate to severe psoriasis.
Guidelines currently recommend biologic medication for most people with a new diagnosis of PsA, unless they have a history of frequent infections. A doctor should discuss the options with the individual.
The NPF provide the following tips for managing stress, which is a major contributor to psoriatic disease flare-ups and depression:
- Take a 10-minute break each day and use the time to destress. Try meditating or practicing a simple breathing exercise, such as inhaling deeply through the nose and exhaling slowly through the mouth.
- Think positive thoughts before going to bed. Those who lie awake worrying can feel stressed and fatigued the following day. Bringing a pleasant memory to mind last thing at night can help distract from negative thoughts.
- Practice counteracting pessimistic thoughts with positive or neutral ones.
As we discussed above, people with PsA may have a higher level of inflammatory cytokines in their blood. These cytokines can contribute to depression by reducing the levels of certain brain chemicals.
Selective serotonin reuptake inhibitors are the most common type of antidepressant. These drugs work by increasing the levels of serotonin in the brain.
Serotonin and norepinephrine reuptake inhibitors are another type of antidepressant. These work by increasing the levels of both serotonin and norepinephrin
Many factors can contribute to depression and low mood among people with PsA. These factors can be related to physical or mental health.
Many treatments and coping strategies can help a person overcome feelings of depression. People who are concerned about depression can talk to a doctor for advice on treatments and coping strategies.