Understanding Different Types Of Depression

What is Depression?

Depression, in the context of mental health, refers to a common and serious medical condition that negatively affects how a person feels, thinks, and handles daily activities. Characterised by persistent feelings of sadness and/or a loss of interest in activities once enjoyed, depression can lead to a variety of emotional and physical problems. It can diminish a person’s ability to function at work and at home.

Depression is more than just a bout of the blues and is not something that can be simply “snapped out” of. It requires long-term treatment. The exact cause of depression is not known, but it’s believed to be a complex combination of genetic, biological, environmental, and psychological factors.

Depression statistics in australia
Prevalence of Depression in Australia

The Prevalence of Depression in Australia

In Australia, depression is a significant mental health challenge affecting the population. According to various sources, around one in five Australians will experience depression in their lifetimes. This statistic underscores the widespread nature of this mental health condition within the country. Depression is particularly prevalent among young people aged between 12-25 years, highlighting the need for targeted mental health support and interventions within this age group. Nonetheless, depression can affect anyone, at any age and therefore it is essential we understand how to identify and treat this common condition.

For the period between 2020 and 2022, it was estimated that 43% of Australians aged 16–85 had experienced a mental disorder at some time in their life, with 22% having experienced a mental disorder in the previous 12 months. Among the mental disorders, anxiety disorders were the most common, followed by Affective Disorders, which include depression, affecting 1.5 million people or 8% of the population

The conditions associated with depression, such as Major Depressive Disorder (MDD), Chronic Depression or Persistent Depressive Disorder, Bipolar Disorder, and Seasonal Depression, vary in terms of duration and severity, indicating the complexity and varied manifestations of depression among the Australian population​​.

What Are The Different Types of Depression And Their Symptoms?

8 Types of Depressions
The most common types of depression

Depression is a complex mental health condition that manifests in various forms, each with its own unique set of symptoms and characteristics. Understanding the different types of depression is crucial for effective diagnosis and treatment. Here are the primary forms of depression:

Major Depressive Disorder (MDD)

Major Depressive Disorder (MDD) is a common but serious mood disorder that affects how a person feels, thinks, and handles daily activities. To be diagnosed with MDD, a person must experience a depressive episode that lasts at least two weeks. 

Symptoms of MDD include: 

  • Persistent feeling of sadness or emptiness
  • Lack of interest or pleasure in activities once enjoyed
  • Significant weight loss or gain
  • Insomnia or excessive sleeping
  • Fatigue or loss of energy
  • Feelings of worthlessness or excessive guilt
  • Difficulty thinking or concentrating
  • Recurrent thoughts of death or suicide

The exact cause of MDD is unknown but is believed to be a combination of genetic, biological, environmental, and psychological factors. 

Persistent Depressive Disorder (PDD)

Persistent Depressive Disorder (PDD), formerly known as dysthymia, is a form of depression characterised by a chronic pattern of depressive symptoms that last for at least two years in adults, and one year in children and adolescents. Unlike Major Depressive Disorder, where symptoms may be more severe but are typically episodic, PDD presents with less severe yet continuous symptoms that can significantly affect an individual’s quality of life and ability to function daily.


Symptoms of Persistent Depressive Disorder typically include 

  • Persistent feeling of sadness or depression
  • Loss of interest in activities
  • Fatigue
  • Low self-esteem
  • Changes in appetite
  • Sleep disturbances (either insomnia or oversleeping)
  • Difficulty concentrating


Individuals with PDD might still be able to go about their daily routines but often feel a consistent underlying sadness or inadequacy. The exact cause of PDD is not known, but it is believed to result from a combination of genetic vulnerability, biochemical factors, environmental influences, and psychological stress. 

It is important for individuals who believe they may have PDD to seek professional medical advice for an accurate diagnosis and treatment plan. With the right treatment approach, people with PDD can experience significant improvements in their symptoms and overall quality of life.

Bipolar Disorder

Bipolar disorder, previously known as manic-depressive illness, is a mental health condition characterised by extreme mood swings that include emotional highs (mania or hypomania) and lows (depression). When a person experiences mood elevation, they may feel euphoric, full of energy, or unusually irritable. These periods are followed by episodes of depression, during which the individual may feel sad, indifferent, or hopeless, with a lack of energy and interest in life.

These mood swings can affect sleep, energy levels, behaviour, judgement, and the ability to think clearly. Episodes of mood swings may occur rarely or multiple times a year. While most individuals will experience some emotional symptoms between episodes, some may not experience any.

There are several types of bipolar disorder, including:

  • Bipolar I Disorder
    This type is characterised by manic episodes lasting at least 7 days or by manic symptoms that are so severe that immediate hospital care is needed. Depressive episodes occur as well, typically lasting at least 2 weeks.
  • Bipolar II Disorder
    Defined by a pattern of depressive episodes and hypomanic episodes, but not the full-blown manic episodes that are typical of Bipolar I Disorder.
  • Cyclothymic Disorder (Cyclothymia)
    Periods of hypomanic symptoms and depressive symptoms lasting for at least 2 years (1 year in children and adolescents); however, the symptoms are not as extreme and therefore do not meet the diagnostic requirements for a hypomanic or  depressive episode.

Seasonal Affective Disorder (SAD)

Seasonal Affective Disorder (SAD) is a type of depression that occurs at a specific time of year, usually in the autumn and winter months, when there is less natural sunlight. It is sometimes referred to as “winter depression” because the symptoms are more apparent and tend to be more severe during the colder, darker months. 

Common symptoms of SAD: 

  • Persistent low mood
  • Loss of pleasure or interest in normal everyday activities
  • Irritability
  • Feelings of despair
  • Guilt and worthlessness
  • Sleeping for longer than usual and finding it hard to get up in the morning
  • Craving carbohydrates
  • Gaining significant amount of weight abnormally

One possible cause of SAD is believed to be linked to reduced exposure to sunlight during the shorter autumn and winter days. The lack of sunlight might stop a part of the brain called the hypothalamus from working properly, which may affect the production of melatonin (a hormone that makes you feel sleepy), serotonin (a hormone that affects your mood, appetite, and sleep), and the circadian rhythm (body’s internal clock)  that regulates several biological processes during a 24-hour period.

Postpartum Depression

Postpartum Depression (PPD) is a severe, long-lasting form of depression that can occur after giving birth. It is more serious than the “baby blues,” which are mild depressive and anxiety symptoms that typically clear up on their own within two weeks of delivery. Postpartum depression can develop from a few weeks to up to a year after childbirth, and its symptoms are much more intense.

Common symptoms of Postpartum Depression:

  • Severe mood swings
  • Excessive crying
  • Difficulty bonding with the baby
  • Withdrawal from family and friends
  • Loss of appetite or overeating
  • Inability to sleep (insomnia) or sleeping too much
  • Overwhelming fatigue or loss of energy
  • Reduced interest and pleasure in activities enjoyed before
  • Intense irritability and anger
  • Fear of not being a good mother
  • Feelings of worthlessness
  • Constant feeling of shame
  • Constant feeling of guilt
  • Difficulty thinking clearly
  • Difficulty in concentrating or making decisions
  • Thoughts of harming oneself or the baby

Premenstrual Dysphoric Disorder (PMDD)

Premenstrual Dysphoric Disorder (PMDD) is a severe form of premenstrual syndrome (PMS) that significantly affects a woman’s emotional and physical health. It is characterised by severe psychological symptoms such as depression, irritability, and tension before menstruation. Unlike PMS, which has milder symptoms, PMDD causes severe and debilitating symptoms that can impact daily functioning and relationships.

Here are the symptoms:

  • Mood swings
  • Sadness or despair
  • Anxiety or tension
  • Extreme irritability or anger
  • Decreased interest in usual activities
  • Difficulty concentrating
  • Constant fatigue
  • Changes in appetite suddenly
  • Sleep problems
  • Physical symptoms such as bloating, breast tenderness, headaches, and joint or muscle pain.

However, these symptoms typically occur during the week before the onset of menstruation and improve within a few days after the period starts.

Atypical Depression

Atypical Depression is a subtype of Major Depressive Disorder characterised by specific features that distinguish it from the classical form of depression. Unlike typical depression where individuals often lose their appetite and struggle to sleep, those with atypical depression may experience increased appetite or weight gain and hypersomnia (excessive sleeping). Other hallmark symptoms include heavy, leaden feelings in the arms or legs, a long-standing pattern of sensitivity to rejection, and a significant improvement in mood in response to positive events.

The causes of atypical depression are not entirely understood but are thought to involve genetic predisposition, neurotransmitter imbalances, and environmental factors. It’s also observed that atypical depression can start in the teenage years and, without treatment, can be chronic and persist throughout an individual’s life.

Psychotic Depression

Psychotic Depression is a subtype of major depressive disorder characterised by the presence of psychotic features, such as delusions or hallucinations, in addition to the typical symptoms of depression. Delusions are false beliefs that are not based in reality, while hallucinations involve seeing or hearing things that are not there. These psychotic symptoms can be very distressing and may relate directly to the individual’s depressive thoughts, such as beliefs of inadequacy, guilt, or worthlessness.

Unlike other forms of depression, those with psychotic depression may have difficulty distinguishing these delusions or hallucinations from reality. This can make psychotic depression particularly challenging to treat and significantly impacts a person’s ability to function in daily life.

If you suspect you or someone you know is experiencing symptoms of psychotic depression, it’s crucial to seek professional help immediately. This condition is treatable, and early intervention can improve outcomes.

Treatments Used For Depression

Alternative treatments for depression symtpoms
Treatment options for depression

The treatment for depression varies depending on the type and severity of the condition, but generally, it involves medication, psychotherapy, or a combination of both. Here’s a brief overview of treatments for different types of depression:


Antidepressants are widely used to treat various types of depression, with different antidepressants  demonstrating effectiveness in improving symptoms for different depressive disorders. According to research, antidepressants can significantly improve symptoms in about 40 to 60 out of 100 people who use them, compared to 20 to 40 out of 100 people who noticed improvement with a placebo. This indicates that antidepressants can be effective in treating major depressive disorder, persistent depressive disorder (dysthymia), and help in preventing relapses of depression when taken over a longer period​​.

It is important to know that although antidepressant is commonly used to help with depression, its usage poses several risks that warrant careful consideration. Firstly, these medications may trigger adverse side effects ranging from nausea and headaches to more severe complications. Additionally, prolonged use can lead to dependency and withdrawal symptoms upon discontinuation.

Specific types of depression that respond well to antidepressants include major depressive disorder and persistent depressive disorder. For major depressive disorder, Selective Serotonin Reuptake Inhibitors (SSRIs) are often the first line of treatment due to their generally fewer side effects compared to older types of antidepressants. For persistent depressive disorder, which is a less severe but more chronic form of depression, antidepressants can also relieve long-term symptoms and help make them go away completely​​.

Additionally, certain conditions like Seasonal Affective Disorder (SAD), postpartum depression, and atypical depression may also respond well to antidepressants. The choice of antidepressant and their effectiveness can vary from person to person, sometimes  requiring  trials of  more than one medication to find the one that works best.  Therefore, it’s crucial for patients and healthcare professionals to weigh the potential risks against the benefits before initiating treatment.


Psychotherapy treats depression by helping individuals understand their thoughts, emotions, and behaviours, and by teaching them coping strategies to manage their symptoms. It provides a supportive environment to discuss feelings and concerns with a trained therapist, who may be able to  offer insights and guidance towards healthier patterns of thinking and behaving. The goal of psychotherapy is not just to alleviate symptoms but also to address the root causes of depression, enabling long-term improvement and preventing relapse.

Cognitive Behavioral Therapy (CBT)
Focuses on identifying and changing negative thought patterns and behaviours that contribute to depression. CBT helps individuals challenge and replace these with more positive and realistic ones, thereby improving mood and reducing depressive symptoms.

Interpersonal Therapy (IPT)
Concentrates on improving interpersonal relationships and communication patterns. It helps individuals understand and work through problematic personal relationships that may contribute to or exacerbate their depression.

Psychodynamic Therapy
Aims to explore unconscious thoughts and feelings, childhood experiences, and unresolved conflicts affecting current behaviour and mood. This insight-oriented therapy helps individuals understand the root causes of their depression.

Problem-Solving Therapy
Focuses on enhancing an individual’s ability to cope with stressful life circumstances. It teaches practical skills to solve problems that contribute to depressive feelings, thereby reducing the impact of stress and improving mood.

Medical Cannabis

Medical cannabis is thought to treat depression by interacting with the endocannabinoid system in the brain, which plays a key role in mood regulation and stress response. Cannabinoids found in cannabis, such as THC (tetrahydrocannabinol) and CBD (cannabidiol), can influence neurotransmitter systems, including serotonin and dopamine pathways, which are often implicated in depression. CBD, in particular, has been noted for its anxiolytic and antidepressant-like effects in various studies, potentially providing relief from symptoms of anxiety and depression without the psychoactive effects associated with THC.

The effectiveness of medical cannabis may vary widely among individuals and different types of depression. Anecdotal evidence and some preliminary studies suggest that patients with mild to moderate depressive symptoms may experience relief with medical cannabis, particularly in terms of reduced anxiety, improved mood, and better sleep. However, there’s a need for more rigorous clinical research to determine which specific types of depression might respond best to treatment with medical cannabis.

It’s important to note that while some individuals report improvements in depressive symptoms with medical cannabis use, others may experience worsening symptoms or additional mental health challenges. The response to medical cannabis can be highly individualised, influenced by factors such as the specific cannabinoid profile of the cannabis used, dosage, individual health conditions, and concurrent use of other medications.

Given the complexity of depression treatment and the potential risks and benefits of using medical cannabis, it’s crucial for individuals considering this treatment option to consult with an appropriate healthcare provider. An appropriate health professional can provide personalised advice based on the latest research, individual health status, and legal considerations related to medical cannabis use in their jurisdiction.

To summarise, in this article we’ve journeyed through the intricacies of conditions ranging from Major Depressive Disorder to Psychotic Disorder and beyond, it’s clear that understanding is just the beginning. Tailoring treatment to the individual, whether through medication, psychotherapy, or innovative approaches like medical cannabis, requires a deep comprehension of each unique experience.

Written by

Priyom holds a Ph.D. in Plant Biology and Biotechnology from the University of Madras, India. She is an active researcher and an experienced science writer. Priyom has also co-authored several original research articles that have been published in reputed peer-reviewed journals. She is also an avid reader and an amateur photographer.

Written by

Priyom holds a Ph.D. in Plant Biology and Biotechnology from the University of Madras, India. She is an active researcher and an experienced science writer. Priyom has also co-authored several original research articles that have been published in reputed peer-reviewed journals. She is also an avid reader and an amateur photographer.

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