PDD is a mood disorder that lasts for a long time, often several years. People with PDD feel sad or low almost every day for at least two years (in adults) or one year (in children).
They also describe feeling sad or down in the dumps as part of their day-to-day experience. Some may say, "I have always been this way," or "That's just how I am." Because of that, family members of those living with PDD often perceive them as being grumpy.
Other symptoms of PDD include difficulty sleeping and eating, and lack of energy or interest in activities. They may have trouble concentrating on tasks. Sometimes, they can also feel indecisive, inadequate, pessimistic or hopeless.
Persistent Depressive Disorder is distinct from Major Depressive Disorder (MDD). MDD is characterised by a depressed mood and other symptoms that usually last for a minimum of two weeks. In contrast, a person with PDD experiences milder but long-term depression symptoms that are debilitating. It does not have an episodic pattern as seen in Major Depressive Disorder. In fact, people with PDD can generally continue with school or work - but with decreased motivation or pleasure.
While the condition may have less impact on daily function compared to MDD, it can still make it harder to lead a happy and fulfilling life. The chronic nature of PDD means that individuals may consistently struggle with a persistent low mood and lack of enjoyment in activities. Relationships, social interactions and personal goals may feel less fulfilling to pursue and lead to feelings of isolation, hopelessness and frustration.
The causes of dysthymia or Persistent Depressive Disorder, like most mental health disorders, are complex. Some potential causes include:
Genetics
Individuals with a family history of mood disorders may be more likely to develop dysthymia.
Brain chemistry
Imbalances in neurotransmitters, such as serotonin, norepinephrine and dopamine pay a role in regulating moods.
Psychological factors
Certain personality traits, like being very hard on oneself or often thinking negatively, can contribute to Persistent Depressive Disorder.
Environmental factors
Adverse childhood experiences, such as trauma, abuse or neglect contribute to the development of mental health conditions. Chronic stress in adult hood and even chronic physical illness can increase the risk of developing dysthymic disorder.
Some people with PDD may feel sad all the time. However they are still able to function normally in their daily life. These individuals should continue to practise self-care strategies like regular exercise, nutrition, stress management and enough sleep to manage symptoms.
However, some may also choose to seek professional help when they realise that their symptoms are not normal. Symptoms can also sometimes worsen during periods of stress or major life changes.
Some signs that may indicate the need for professional help in PDD include:
- Impairment in daily function
- Social withdrawal
- Strained relationships
- Decline in self-care
- Substance abuse
- Suicidal thoughts
Professional treatment options for Persistent Depressive Disorder include psychotherapy and medication (such as selective serotonin reuptake inhibitors).
Cognitive behavioural therapy (CBT) and insight-oriented psychoanalytic therapy are some examples of talk therapy. Mindfulness-based CBT can help patients cope with the symptoms in the long term. These therapies help participants identify and change negative thought patterns or behaviours. In addition, psychodynamic therapy or interpersonal therapy may help individuals explore underlying causes of their depression and develop healthier ways of thinking and relating to others.
What is the estimated prevalence of Persistent Depressive Disorder?
There are no statistics for PDD or dysthymia in Singapore. The estimated prevalence of PDD varies in different studies and populations. According to the fifth edition of the Diagnostics and Statistical Manual of Mental Disorders (DSM-5), the estimated lifetime prevalence of PDD in the general population is approximately 2.5%. This means that about 2.5% of individuals will experience PDD at some point in their lives.
What is double depression?
It is possible for individuals to have both PDD and MDD at the same time. This is known as 'double depression' when someone with PDD also undergoes a major depressive episode. When both conditions are present, the person still has ongoing feelings of depression along with more severe symptoms of MDD. During these episodes, they may be at a higher risk for more significant impairments to their daily life, or suicide ideation.
Is there a way to prevent a person from developing Persistent Depressive Disorder?
While it's not possible to completely prevent an individual from developing PDD, there are strategies that can help reduce the risk or potentially mitigate the severity of depressive symptoms. These include developing resilience and coping skills, maintaining a healthy lifestyle with sufficient sleep, avoiding excessive alcohol or drug use, seeking early intervention, building a strong support system around oneself, and employing techniques such as mindfulness, self-care practices and stress management.
