The primary mental illness known for causing significant mood swings is Bipolar Disorder, characterized by extreme shifts between manic highs and depressive lows, but other conditions like Borderline Personality Disorder (BPD), major depression, anxiety, and sometimes even ADHD can involve rapid mood changes, though BPD's emotional volatility is often more intense and linked to unstable self-image and relationships.
People with borderline personality disorder often experience intense mood swings and uncertainty about how they see themselves. Their interests, values, and feelings can change quickly. They also tend to view things in extremes, such as all good or all bad.
The main symptom of bipolar disorder is extreme changes to your mood. You sometimes have either: high moods (mania or hypomania) – for example, feeling very happy, excited or energetic. low moods (depression) – for example, feeling sad, tired or hopeless.
Five key signs of bipolar disorder involve extreme mood shifts, including manic symptoms like inflated energy, reduced need for sleep, racing thoughts, impulsivity (spending, risky behavior), and irritability, alongside depressive symptoms such as profound sadness, loss of interest, fatigue, significant sleep/appetite changes, and suicidal thoughts, all lasting for extended periods and impacting daily life.
Here are some of the most common causes:
For example, you might go from feeling happy to irritated to sad during the day, depending on what's happening in your life. Symptoms of bipolar disorder are different. With bipolar disorder, manic episodes last at least 7 days, and depressive episodes (feeling very low) usually last at least 2 weeks.
What to Do If Your Partner's in a Bad Mood
The first red flag of bipolar disorder often appears as significant changes in sleep patterns, mood instability (irritability/euphoria), increased energy/agitation, and rapid thoughts/speech, frequently mistaken for unipolar depression or normal moodiness, with sleep disruption (insomnia or oversleeping) and heightened irritability being very common early signs, notes Better Mental Health.
At the outset, bipolar symptoms are commonly mistaken for ADHD, depression, anxiety, borderline personality disorder, and, in its more severe manifestations, as schizophrenia.
Age at onset of type-I bipolar disorder (BPD) typically averages 12-24 years, is older among patients with type-II BPD, and oldest in unipolar major depressive disorder 1,2,3. Reported onset ages probably vary by ascertainment methods, and possibly among different countries and cultures 1,2,3,4,5,6.
Mood changes: You might feel intense emotions like uncontrollable anger, fear, anxiety, hatred, sadness and love. These moods change often and quickly. They usually only last a few hours and rarely more than a few days.
Overview. Cyclothymia (sy-kloe-THIE-me-uh), also called cyclothymic disorder, is a rare mood disorder. Cyclothymia causes emotional ups and downs, but they're not as extreme as those in bipolar I or II disorder. With cyclothymia, you experience periods when your mood noticeably shifts up and down from your baseline.
To diagnose bipolar disorder, a doctor performs a physical exam, asks about your symptoms, and recommends blood testing to determine if another condition, such as hypothyroidism, is causing your symptoms. If the doctor does not find an underlying cause of your symptoms, he or she performs a psychological evaluation.
BPD Meltdown
During a meltdown, people may experience extreme mood swings, impulsivity, and difficulty calming down. Understanding how BPD contributes to meltdowns is crucial for developing coping strategies and providing support to manage and navigate these overwhelming emotional experiences.
Bipolar disorders feature mood swings that include emotional highs called manic or hypomanic episodes, and lows, called depressive episodes. These highs and lows are usually continuous. But they also can change from high to low or low to high — or shift into a normal mood.
People who have borderline personality disorder (BPD) have intense mood swings and trouble with emotional regulation. Unlike bipolar disorder, their strong feelings often revolve around their self-image and relationships with others.
Symptoms of bipolar disorder
Schizoaffective disorder is a mental health condition that is marked by a mix of schizophrenia symptoms, such as hallucinations and delusions, and mood disorder symptoms, such as depression, mania and a milder form of mania called hypomania.
Overall, results suggest that having borderline personality disorder, as opposed to any particular set of criteria, increases the odds that a person may at one time or another be misdiagnosed with bipolar disorder. Misdiagnosis of borderline personality disorder as bipolar disorder has serious clinical implications.
This can lead to yelling, blaming, impulsive arguments, or even physical outbursts—behaviors that may strain relationships and cause deep regret once the episode subsides. Understanding that manic anger is a symptom of bipolar disorder—not a reflection of character or willpower—is essential to recovery.
Symptoms of BPD can include:
A pattern of intense and unstable relationships with others. This is where feelings can change quickly from love and closeness to hatred and anger. chronic feeling of emptiness. Impulsive or reckless behaviour, such as shopping sprees, gambling, substance abuse or unsafe sex.
Mood-stabilizing medicines help control manic or hypomanic episodes. They also may help depressive bouts. Examples include lithium (Lithobid), valproic acid, divalproex sodium (Depakote, Depakote ER), carbamazepine (Tegretol, Tegretol XR, Equetro, others) and lamotrigine (Lamictal).
Moody people avoid facing and resolving their personal conflicts when others accept the blame and cater to them. They get stuck in narcissistic tendencies, immaturity, and controlling behavior toward others.
Walkaway husband syndrome describes a pattern where a husband emotionally detaches, often silently, and then abruptly leaves the marriage, frequently without warning or genuine attempts to resolve issues, leaving his partner confused and hurt. It's characterized by a sudden shift in behavior, increased withdrawal, resentment, blaming the spouse, and sometimes an affair, often stemming from long-term, unaddressed personal unhappiness or marital problems the husband failed to communicate.
The 5-5-5 rule in marriage is a mindfulness and communication tool that encourages couples to pause and ask themselves: Will this matter in 5 minutes, 5 days, or 5 years? It's designed to help de-escalate conflict and shift focus to what truly matters.