Mood Disorders – What are they?

Samir Kadri
Author: Samir Kadri Medical Reviewer: Rychel Johnson Last updated:

“Mood disorders” is an umbrella term used to describe a range of depressive and bipolar disorders. If you have a mood disorder, your everyday emotional state inhibits your ability to function optimally.

All of us feel sad and low from time to time. However, mood disorders are more extreme and far harder to cope with than normal feelings of sadness.

People of all ages can experience mood disorders, though they are harder to diagnose in children. This is because children are less able to communicate how they feel [1].

Types of mood disorders

Major Depressive Disorder (MDD)

Characterized by an all-pervasive sadness, MDD affects your ability to function effectively at home and work. This sadness can manifest in a variety of physical and behavioral problems. Daily activities can feel incredibly difficult: life can, at times, not feel worth living. The World Health Organisation forecasted MDD to be the number one cause of disease by 2030 [2].

Typical symptoms include a persistently depressed mood, loss of interest in everyday activities, decreased appetite, low energy levels, insomnia, feelings of worthlessness, and suicidal thoughts.

Bipolar Disorders

Bipolar disorders are typified by episodes of mania and depression. If you have bipolar disorder, you may experience extreme mood swings between mania and depression.

An episode of mania followed by an episode of depression is known as a ‘bipolar cycle’. The frequency of bipolar cycles varies from patient to patient; they can last anywhere between hours and months.

Symptoms of bipolar disorders depend on whether you’re undergoing a depressive or manic episode.

During a depressive episode, you can have prolonged feelings of worthlessness and self-loathing which can lead to suicidal thoughts. Other symptoms include a sense of restlessness, lack of interest in any activities, feeling barely able to speak, inability to make decisions, and an all-consuming sense of worthlessness.

When experiencing a manic episode, you may feel an intense sense of euphoria and excessively high energy levels. You may also feel a decreased need for sleep, enhanced creativity levels, and a heightened sense of power. You may also feel restless and be able to talk noticeably faster about multiple topics at once.

Whilst these can seem like positive forces in your life, mania can be dangerous. You feel as though you cannot be harmed, and you lose your inhibitions. This can lead to you spending money frivolously, misusing drugs or alcohol, and/or generally jeopardizing your safety.

There are three types of bipolar disorder: 

  • Bipolar I disorder is characterized by manic episodes that last at least 7 days. These are usually preceded or followed by depressive episodes, usually lasting 2 weeks or longer [3].
  • Bipolar II disorder is typically less severe than Bipolar I. If you are diagnosed with Bipolar II, you experience hypomanic episodes followed by episodes of depression. Hypomania is a milder form of mania, but if left untreated it may evolve into mania.
  • Cyclothymic disorder is characterized by persistent hypomanic and depressive symptoms that are too mild to be regarded as manic/depressive episodes.

Seasonal affective disorder (SAD)

Seasonal affective disorder (SAD) only affects sufferers during certain seasons of the year. SAD is commonly experienced in winter and fall, where a lack of heat and sunlight may lead to an episode.

However, you may also experience SAD in the summer and feel better in the winter.

Symptoms can include a depressed mood, inattentiveness, hopelessness, social withdrawal, and fatigue [4].

Persistent depressive disorder (PDD)

Persistent depressive disorder (PDD) is a milder mood disorder than MDD requiring 2 or more years of depressive symptoms being felt without improvement for diagnosis.

Alongside the 2 years of depressive symptoms, at least 2 of the following symptoms must be present for diagnosis: poor appetite or overeating, low energy, insomnia, low self-esteem, poor concentration, or hopelessness [5].

What causes mood disorders?

There are several different risk factors that can contribute to the development of mood disorders:

  • Hereditary: If you have a family history of a mood disorder, you’re more likely to develop mood disorders. Research found that “people with a family member with a mood disorder are about 2.8 times more likely to have depression” [6].
  • Environment: Our social environments impact us in many ways, and these can lead to mood disorders. Traumatic events such as physical/sexual abuse or emotional upheaval such as the sudden death of a loved one can trigger the development of depression.
  • Physical: It is widely thought that bipolar disorder may be a result of chemical abnormalities in the brain. Whilst hereditary genetic factors play a major role in the development of bipolar disorder, research shows that there is a direct correlation between the amount of the neurotransmitter, noradrenaline, and episodes of mania and depression [7].

How are mood disorders diagnosed?

If you think you have a mood disorder, talk to your doctor. They will attempt to rule out other causes of your symptoms by asking you questions, performing a physical exam, and conducting lab tests. For example, hyperthyroidism has similar physical and emotional symptoms to bipolar disorder and can be ruled out by your doctor during their investigation.

The doctor will then refer you to a psychiatrist or psychologist if they feel you need further consultation. This is where you’ll undergo a psychiatric evaluation and a comprehensive investigation into your medical history.

The psychiatrist will ask you how you feel leading up to bouts of mania or depression. They will also ask if you have any thoughts of harming yourself. It is vital to be as honest and open with them as possible.

The following is a list of the symptoms required for a diagnosis of prominent mood disorders:

Major Depressive Disorder (MDD)

Diagnosis of major depressive disorder (MDD) requires 5 or more of the following symptoms to be present every day for a minimum of 2 weeks.

One of the symptoms must be either a prolonged depressed mood or anhedonia (loss of interest/pleasure in previously enjoyed activities). Secondary symptoms include decreased appetite, insomnia, psychomotor agitation, persistently low energy levels, feelings of worthlessness, unjustifiable guilt, and suicidal thoughts [8].

Bipolar disorder I

To be diagnosed with bipolar disorder, you must have experienced one or more episodes of mania. These episodes must last at least 7 days or have resulted in hospitalization for diagnosis to occur [9]. Whilst you can suffer from both episodes of mania and depression, only mania is essential for a bipolar diagnosis.

How are mood disorders treated?

There are numerous options available to treat mood disorders including a range of medications, self-care regimes, and therapy. 

Cognitive Behavioral Therapy (CBT)

CBT is a form of talking therapy. Its aim is to identify, challenge, and eradicate harmful thought patterns which contribute to low mood and emotional stress [10]. Then, these can be replaced with desirable modes of thought which enable you to function better in your daily life.

CBT can help you manage both depressive and bipolar disorders [10]. It can be conducted online or in person and offers you a cost-effective, proactive way of working through your mood disorder.

Studies have shown that CBT has a positive impact on the treatment of anxiety and depression in children and adolescents [11]. 

Light Therapy

Light therapy can be used to treat seasonal affective disorder. Upon waking up each day, you sit close to a designated light box which is meant to mimic natural light. This is meant to have a positive impact on neurotransmitters linked to your mood.

A medical professional will advise on what lightbox to purchase, and you can discuss best practices for using one. This will ensure you use the tool in as effective and safe a manner as possible.


Lithium has been proven to be effective in the management of bipolar disease. It has proven effective in reducing the number of manic and depressive episodes whilst also diminishing the risk of suicidal thoughts [12].

Potential long-term side effects of taking lithium include the development of hyperthyroidism and kidney damage after 15+ years of lithium treatment [13].

FDA-approved drugs for bipolar treatment

The following is a list of FDA-approved drugs for bipolar treatment [14]

  • quetiapine
  • lurasidone
  • cariprazine
  • olanzapine with fluoxetine

It is essential to consult a medical professional before embarking on a course of a drug or antidepressants. They will prescribe your dosage and talk you through the risks and benefits of embarking on your treatment.

  1. Lee, H. J., Kim, S. H., & Lee, M. S. (2019). Understanding Mood Disorders in Children. Frontiers in Psychiatry, 251–261.
  2. Malhi, G. S., & Mann, J. J. (2018). Depression. The Lancet, 392(10161), 2299–2312.
  3. Bipolar Disorder. (n.d.-b). National Institute of Mental Health (NIMH).
  4. Munir S, Abbas M. Seasonal Depressive Disorder. [Updated 2022 Mar 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from:
  5. Patel RK, Rose GM. Persistent Depressive Disorder. [Updated 2022 Jun 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from:
  6. Nierenberg, A. A., Trivedi, M. H., Fava, M., Biggs, M. M., Shores-Wilson, K., Wisniewski, S. R., Balasubramani, G., & Rush, A. J. (2007). Family history of mood disorder and characteristics of major depressive disorder: A STAR∗D (sequenced treatment alternatives to relieve depression) study. Journal of Psychiatric Research, 41(3–4), 214–221.
  7. Kurita, M. (2016). Noradrenaline plays a critical role in the switch to a manic episode and treatment of a depressive episode. Neuropsychiatric Disease and Treatment, Volume 12, 2373–2380.
  8. American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders, Text Revision Dsm-5-tr(5th ed.). Amer Psychiatric Pub Inc.
  9. Bipolar disorder | NAMI: National Alliance on Mental Illness. (n.d.).
  10. Hofmann, S.G., Asnaani, A., Vonk, I.J.J. et al.The Efficacy of Cognitive Behavioral Therapy: A Review of Meta-analyses. Cogn Ther Res 36, 427–440 (2012).
  11. Choque Olsson, N., Juth, P., Högberg Ragnarsson, E., Lundgren, T., Jansson-Fröjmark, M., & Parling, T. (2021). Treatment satisfaction with cognitive-behavioral therapy among children and adolescents with anxiety and depression: A systematic review and meta-synthesis. Journal of Behavioral and Cognitive Therapy, 31(2), 147–191.
  12. Machado-Vieira R, Manji HK, Zarate CA Jr. The role of lithium in the treatment of bipolar disorder: convergent evidence for neurotrophic effects as a unifying hypothesis. Bipolar Disord. 2009 Jun;11 Suppl 2(Suppl 2):92-109. doi: 10.1111/j.1399-5618.2009.00714.x. PMID: 19538689; PMCID: PMC2800957.
  13. McKnight, R. F., Adida, M., Budge, K., Stockton, S., Goodwin, G. M., & Geddes, J. R. (2012). Lithium toxicity profile: a systematic review and meta-analysis. The Lancet, 379(9817), 721–728.
  14. Kadakia, A., Dembek, C., Heller, V., Singh, R., Uyei, J., Hagi, K., Nosaka, T., & Loebel, A. (2021). Efficacy and tolerability of atypical antipsychotics for acute bipolar depression: a network meta-analysis. BMC Psychiatry, 21(1).
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Samir Kadri
Author Samir Kadri Writer

Samir Kadri is a medical writer with a non-profit sector background, committed to raising awareness about mental health.

Published: Jan 13th 2023, Last edited: Oct 27th 2023

Rychel Johnson
Medical Reviewer Rychel Johnson LCPC

Rychel Johnson is a licensed professional counselor and medical reviewer with a Master's Degree in Psychology from The University of Kansas.

Content reviewed by a medical professional. Last reviewed: Jan 13th 2023