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11 Warning Signs of Mental Health Issues You Should Know
11 subtle but serious mental health symptoms to watch for—early detection can lead to better outcomes and support when it matters most.
It’s easy to brush off a bad mood, poor sleep, or constant stress as “just life.” But what if these are early warning signs of something deeper?
Mental health problems often start quietly—subtle changes in thinking, feeling, or behavior that are easy to dismiss. Yet catching these mental health red flags early can make all the difference.
Whether you’re concerned about yourself or someone you care about, understanding the early symptoms of mental health issues is crucial. Ignoring them can lead to worsening symptoms, strained relationships, and even long-term consequences.
Here are 11 mental health warning signs you should never ignore—and what to do if you recognize them.
Mental health problems often start quietly—subtle changes in thinking, feeling, or behavior that are easy to dismiss. Yet catching these mental health red flags early can make all the difference.
SLEEP CHANGES
When your sleep patterns start to change drastically, it could signal a potential mental health issue. For example, significant shifts in your circadian rhythm or physical health—such as insomnia or oversleeping—often point to conditions like depression or anxiety.
In a 2019 study, up to 90% of people with depression experienced sleep disturbances. Sleep problems can exacerbate feelings of stress and become a cycle that’s difficult to break.
2. APPETITE OR WEIGHT SHIFTS
Similarly, whether eating too little or too much, changes in your appetite can indicate underlying mental health conditions like depression, anxiety, or eating disorders. Sudden weight gain or weight loss can also be a sign of a mental disorder.
For example, research shows that appetite and weight fluctuations are common in people with major depressive disorder. Some people lose their appetite while others feel hungrier than usual.
3. MOOD CHANGES
If you’re experiencing low moods or having rapid or dramatic shifts in mood, it could be an indicator of a mental disorder. Persistent feelings of sadness, emptiness, or irritability are common signs of depression, which affects 29% of US adults at some point in their lives, according to a recent Gallup Poll.
On the flip side, feelings of euphoria that come and go may make you feel amazing in the short-term but might be a sign that something’s wrong. For example, people with bipolar disorder might fluctuate between high-energy manic states and deep depressive episodes.
If you or someone you know is experiencing chronic low moods or extreme emotional ups and downs, it could be time to seek help from a mental health professional.
Press Play to Discover the Warning Signs of Mood Disorders
In this video, Amen Clinics psychiatrist Dr. Jay Faber reveals a specific behavior pattern that’s a common sign of bipolar disorder.
4. SOCIAL WITHDRAWAL
If you’re increasingly isolating yourself from social activities or withdrawing from relationships you once enjoyed, it could signal a deeper issue that needs to be evaluated. Loss of interest in previously enjoyed activities or avoiding interactions with friends and family can be a sign of depression or other mental health conditions.
Understand that this is not about the natural progression of certain relationships or growing out of certain hobbies. This is about having the desire to want to enjoy those parts of your life again—except your mind isn’t allowing you to feel that desire and continue enjoying it.
Social withdrawal is often linked to a lack of energy or motivation, both of which are common when dealing with mental health disorders. A NIMH report showed approximately 20% of U.S. adults experience some form of mental illness annually, with social withdrawal being a hallmark symptom.
5. TROUBLE WITH DAILY FUNCTIONING
If you are someone who previously excelled at work, school, or social activities, but you’re suddenly struggling to keep up with your tasks, it could indicate mental health issues. Research shows that it’s important to pay attention to daily functioning problems, such as:
- Neglecting responsibilities and/or hygiene
- Difficulty completing basic tasks like cleaning or organizing
- Struggling to meet deadlines or keep up with workload demands
- Experiencing difficulty concentrating or retaining information
- Forgetting important appointments, commitments, or responsibilities
These may be signs of mental health issues, such as depression, anxiety, bipolar disorder, or attention deficit hyperactivity disorder (ADHD), also known as attention deficit disorder (ADD). When these are left untreated, your ability to work and interact socially can be significantly and negatively impacted.
If your performance has noticeably decreased in one or more areas of life, it’s important to explore the possibility of a mental disorder with a trusted and qualified mental health professional.
6. DIFFICULTY FOCUSING
Everybody experiences times when it’s challenging to stay on task. But if your problems with focus and concentration persist and get in the way of your success, it could be a sign of trouble. Focus and attention problems are hallmark signs of ADHD, but they can also be linked to other mental health disorders.
For example, research shows that cognitive issues like poor focus are experienced by nearly 50% of people with depression and anxiety disorders. If these symptoms interfere with work or daily life, you need to seek professional help to assess potential mental health disorders.
Related: 5 Simple Ways to Boost Your Focus
7. HEIGHTENED SENSITIVITY
A heightened sensitivity to environmental stimuli—think light, sounds, smells, or textures—can signal an overactive nervous system. This is then often triggered by stress, anxiety, or trauma.
If you find yourself avoiding public places, loud environments, or large crowds because you become overwhelmed by external stimuli, it could be a red flag. Your hypersensitivity may be a sign of posttraumatic stress disorder (PTSD), ADHD, or anxiety.
The Anxiety and Depression Association of America (ADAA) reports that anxiety disorders affect 40 million adults in the U.S. Many of those struggling with anxiety disorder also experience sensory sensitivities or overload as part of their condition.
8. FEELING NUMB OR DETACHED
When you start to feel detached from yourself or your surroundings, or lose interest in life, it’s important to give yourself space to learn why. This feeling of disconnection, also known as depersonalization, can make a person feel as though they are observing life from the outside.
This symptom is common in those with major depressive disorder, where emotional numbness can take over and result in apathy toward daily activities or people. If you find yourself or a loved one lacking initiative or experiencing emotional numbness, it’s important to seek help from a mental health professional.
9. ILLOGICAL OR DISORDERED THINKING
Mental disorders like bipolar disorder or schizophrenia can cause illogical thinking or delusions that lead people to believe in exaggerated or false thoughts about themselves or the world. These beliefs might include thoughts of grandeur or the idea that you have special powers to control events around you.
According to the World Health Organization, approximately 1 in 300 people worldwide experience schizophrenia in their lifetime, often manifesting as distorted thinking and perceptions. If someone’s beliefs seem out of touch with reality or become more outlandish, it may indicate a serious mental health condition that requires intervention.
10. NERVOUS OR FEARFUL BEHAVIOR
Excessive nervousness, fear, or paranoia can be symptoms of anxiety disorders, including generalized anxiety disorder (GAD) or social anxiety disorder. Uncharacteristic behavior like erratic speech or avoiding everyday tasks due to irrational fears, often points to an underlying issue.
The NIMH reports nearly 30% of adults in the U.S. experience an anxiety disorder in their lifetime. Most of them report symptoms such as hypervigilance and hyper-avoidance of triggering situations. If you or someone you love seems to be living in constant fear, it may be time to seek professional mental health guidance.
Related: 4 Steps to Break an Anxiety Attack
11. CHANGES IN SCHOOL OR WORK PERFORMANCE
A sudden change in your performance at school or work can be an early warning sign of a mental disorder. Such changes may include:
- Finding it difficult to keep up with responsibilities
- Having trouble staying focused
- Increased absenteeism
- Experiencing conflicts with colleagues or classmates
If your productivity isn’t what it used to be, you may want to take a deeper dive to investigate what’s causing the drop in performance.
FINAL THOUGHTS: DON’T IGNORE SIGNS OF MENTAL HEALTH ISSUES
Recognizing mental health symptoms early can be critical to getting the right help and support. They should not be dismissed lightly. Getting an early diagnosis means early intervention, so you can better manage your symptoms and improve your overall quality of life.
Anxiety, depression, and other mental health conditions can’t wait. At Amen Clinics, we provide personalized, science-backed treatment plans designed to target the root causes of your symptoms. Our 360-approach includes brain SPECT imaging, clinical evaluations, innovative therapeutic techniques, medications (when necessary), and holistic lifestyle recommendations to promote the health of your brain, body, and mind. Speak to a specialist today at 888-288-9834 or visit our contact page here.
Amen Clinics
Founded in 1989 by double-board certified psychiatrist and neuroscientist Daniel G. Amen, MD, Amen Clinics Inc. (ACI) is known as the best brain and mental health company in the world. Our clinical staff includes over 50 healthcare specialists, including adult and child psychiatrists, integrative (functional) medicine physicians, naturopaths, addiction specialists, forensic psychiatrists, geriatric psychiatrists, nutritionists, licensed therapists, and more. Our clinicians have all been hand-selected and personally trained by Dr. Amen, whose mission is to end mental illness by creating a revolution in brain health. Over the last 35-plus years, ACI has built the world’s largest database of functional brain scans—over 250,000 SPECT scans on patients from 155 countries—related to how people think, feel, and behave.
Stickley, A., Leinsalu, M., DeVylder, J.E. et al. Sleep problems and depression among 237 023 community-dwelling adults in 46 low- and middle-income countries. Sci Rep 9, 12011 (2019). https://doi.org/10.1038/s41598-019-48334-7https://www.nature.com/articles/s41598-019-48334-7#citeas
Simmons, W Kyle et al. “Depression-Related Increases and Decreases in Appetite: Dissociable Patterns of Aberrant Activity in Reward and Interoceptive Neurocircuitry.” The American journal of psychiatry vol. 173,4 (2016): 418-28. doi:10.1176/appi.ajp.2015.15020162
Witters D. U.S. Depression Rates Reach New Highs, GALLUP. May 17, 2023. https://news.gallup.com/poll/505745/depression-rates-reach-new-highs.aspx
National Institute of Mental Health. (2024, September). Mental Illness. www.nimh.nih.gov/health/statistics/mental-illnesshealth
Keller AS, Leikauf JE, Holt-Gosselin B, Staveland BR, Williams LM. Paying attention to attention in depression. Transl Psychiatry. 2019 Nov 7;9(1):279. doi: 10.1038/s41398-019-0616-1. Erratum in: Transl Psychiatry. 2020 Feb 12;10(1):64. doi: 10.1038/s41398-020-0748-3. PMID: 31699968; PMCID: PMC6838308
Perini G, Cotta Ramusino M, Sinforiani E, Bernini S, Petrachi R, Costa A. Cognitive impairment in depression: recent advances and novel treatments. Neuropsychiatr Dis Treat. 2019 May 10;15:1249-1258. doi: 10.2147/NDT.S199746. PMID: 31190831; PMCID: PMC6520478
National Institute of Mental Health. (2024). Any Anxiety Disorder. Retrieved from www.nimh.nih.gov/health/statistics/any-anxiety-disorder
Inside the Neurodivergent Brain: What Brain Imaging Reveals
Brain imaging reveals how neurodivergent brains differ in function and activity—offering new hope for diagnosis and treatment.
While the terms “neurodivergent” and “neurodiversity” are not new, they’ve gained significant traction in recent years. Still, many people harbor confusion about their exact meaning and the conditions they describe.
Diagnoses for neurodiverse conditions such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD)—also called attention deficit disorder (ADD)—are on the rise. At the same time, growing research and awareness are helping to shed light on other neurodiverse traits, such as dyslexia, and how they affect thinking, learning, and behavior.
With increased awareness, we now recognize that these brains are simply wired differently. At Amen Clinics, we’ve seen this firsthand. For decades, we’ve used functional brain scans with SPECT (single photon emission computed tomography) to reveal the unique activity patterns that distinguish neurodivergent brains from neurotypical brains.
For decades, Amen Clinics has used functional brain scans with SPECT (single photon emission computed tomography) to reveal the unique activity patterns that distinguish neurodivergent brains from neurotypical ones.
UNDERSTANDING THE NEURODIVERGENT BRAIN
Since the 1970s, SPECT scans have helped medical experts understand how the brain works. Today, this state-of-the-art imaging tool evaluates blood flow and activity in different regions of the brain. SPECT shows what areas of the brain are working well, too hard, or not hard enough.
Meanwhile, the terms neurodivergent and neurodiversity have been used since the 1990s. They are frequently credited to Australian sociologist Judy Singer, as well as (in more recent research) to the collective of neurodivergent people themselves. Neurodivergence refers to brains that developed differently.
As the U.K.-based organization ADHD Aware points out, neurodevelopmental conditions like ADHD and ASD present symptoms, behaviors, and traits that result from these developmental differences. They can occur before birth or in the early stages of childhood.
This distinguishes neurodivergence from a mental health condition. In the latter, patterns of behavior or state of mind deviate from the “normal self.” But neurodevelopmental conditions denote a different “normal” altogether.
ADHD Aware adds that the roots of neurodevelopmental conditions may be found in:
- Genetics
- Trauma at birth
- Infectious diseases
- Immune disorders
- Nutrition
- Physical trauma
While these brains work differently, they can also have unique strengths. Let’s look at some ways neurodiversity can affect brain function, according to findings from SPECT scans at Amen Clinics.
Related: The ABCs of the Human Immune System
FUNCTIONAL BRAIN DIFFERENCES IN ADHD
An estimated 7 million (11.4%) U.S. children from ages 3-17 had ever been diagnosed with ADHD in 2022, according to the Centers for Disease Control (CDC). That reflects a 1-million increase compared to statistics compiled in 2016.
Over decades of performing brain scans, Amen Clinics has determined that there are actually seven types of ADD. Each has its own unique set of symptoms, but generally ADHD brains show differences when trying to concentrate.
In the neurotypical brain, concentration would increase blood flow in certain regions—especially in the prefrontal cortex (PFC). This region is key in planning, focus, organization, and follow-through.
Healthy Neurotypical Brain SPECT Scan
However, during moments of concentration, people with ADHD will experience a blood flow decrease in the PFC. Trying harder to concentrate actually makes the task more difficult.
Related: What Is the Executive Center of the Brain
Here is an overview of differences in brain function for each of the seven types of ADHD:
Type 1: Classic ADD is often called ADHD, due to the presence of hyperactive behavior. Hallmark traits include being inattentive, easily distracted, and restless or fidgety.
Classic ADD Neurodivergent Brain SPECT Scan
Type 2: Inattentive ADD, the second most common type, is associated with being quieter, more introverted, and prone to daydreaming. These individuals can also have trouble focusing but don’t usually show the behavior problems that characterize Classic ADHD.
In Types 1 and 2, the brain appears normal at rest. But during times of concentration, there tends to be decreased activity in the underside of the PFC, as well as in the cerebellum and basal ganglia.
Type 3: Overfocused ADD relates to difficulties with shifting attention. Brain scans show increased activity, even at rest. Increased activity occurs in the anterior cingulate gyrus (the brain’s “gear-shifter”), while decreased activity affects the underside of the PFC, the cerebellum, and the basal ganglia.
Type 4: Temporal Lobe ADD can create issues with learning and memory, unstable mood, and aggression. SPECT scan findings highlight decreased (and occasionally increased) activity in the temporal lobes, both at rest and during concentration.
Concentration also triggers decreased activity in the underside of the PFC, the cerebellum, and the basal ganglia.
Type 5: Limbic ADD involves an underactive prefrontal cortex during concentration, while the deep limbic area (involved with mood) is overactive. SPECT scans typically show increased deep limbic activity at rest, and decreased activity in the PFC, cerebellum, and basal ganglia during concentration.
Type 6: Ring of Fire ADD is associated with overall high activity in the brain, which can lead to overwhelming thoughts and emotions. These patchy areas of increased activity often affect multiple areas of the brain, creating a “ring” shape, but patterns can vary from person to person.
Type 7: Anxious ADD corresponds with areas of low activity as well as overactivity—and the resulting anxiety can aggravate ADHD symptoms. Brain scans show increased activity in the basal ganglia at rest and during concentration. In the PFC and cerebellum, activity decreases during concentration.
WHAT DO BRAIN SCANS FOR AUTISM SHOW?
Like ADHD, autism diagnoses are also increasing. According to the CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network, about 1 in 31 (3.2%) 8-year-old children had been identified with autism spectrum disorder in 2022. In 2020, that number was 1 in 36.
Any of the following symptoms, ranging from mild to severe, can accompany ASD:
- Deficiencies in social and communication skills
- Limited and repetitive behaviors and interests
- Developmental disabilities, including intellectual and language impairments
The differences in early brain development associated with ASD relate to the way neurons communicate with one another. This can lead to a variety of issues, including difficulty performing everyday tasks.
However, ASD does not point to a single brain problem in adults and children. In fact, a suspected eight to 10 factors can influence abnormal brain function and lead to this type of neurodivergence.
Brain-imaging studies of people with autism reveal that their brain patterns tend to have areas of high activity, low activity, or areas of both. Abnormal activity often affects the cerebellum, anterior cingulate gyrus, amygdala, and the temporal, frontal, and parietal lobes.
Therefore, there are high and low activity patterns in ASD. High activity patterns describe increased activity in the anterior cingulate gyrus and lateral prefrontal cortex. This is linked to symptoms such as repetitive speech and behavior. Increased activity in the brain can also contribute to mood instability or anxiety.
Low activity patterns, meanwhile, tend to accompany a smaller, less active cerebellum. This is associated with diminished motor skills and problems with learning and thought coordination. Overall, the surface of the brain, as well as the parietal and temporal lobes, have decreased activity, affecting communication, language, and social skills.
Autism Brain SPECT Scan
OTHER FORMS OF NEURODIVERGENCE
In addition to ADHD and autism, neurodivergence can take numerous other forms. Here are some of the most common types:
Dyslexia, which describes reading impairment and affects about 20% of the population. SPECT scans of individuals with dyslexia often show decreased activity in two brain regions: the prefrontal cortex and the left temporal lobe.
Dyslexia is a type of specific learning disorder (SLD), a grouping that includes other neurodivergent conditions, such as:
- dysgraphia (writing impairment)
- dyscalculia (math impairment)
The American Psychiatric Association (APA) estimates that 5-15% of school-age children have a learning disability.
Dyspraxia, also called developmental coordination disorder (DCD), affects motor abilities. In the past, researchers struggled to pinpoint its best diagnosis and management. Today, while more research is still needed, studies have linked several brain areas to this condition: the cerebellum, basal ganglia, parietal lobe, and parts of the frontal lobe.
The APA defines neurodiversity as a “concept that regards individuals with differences in brain function and behavioral traits as part of normal variation in the human population.” Therefore, this definition includes, in addition to all of the above:
- Dysphonia (disorders affecting the voice)
- Tourette syndrome
- Synesthesia (the linking of two senses, such as sight and sound)
- Other behavioral and neurobiological differences
THE IMPORTANCE OF BRAIN IMAGING IN NEURODIVERGENCE
Neurodivergence can easily be misdiagnosed or simply remain untreated. And, because disorders like autism and ADHD are complex and assume multiple forms, brain imaging is instrumental in guiding accurate diagnosis and effective, targeted treatment plans.
Press Play to Learn About ADHD Interventions
In this video, Amen Clinics psychiatrist Dr. Steven Storage reveals natural ways to heal ADHD—without medication.
Click below to tune in:
Through improved understanding of the neurodivergent brain and neurodivergent thinking, mental health professionals can provide brain-based interventions to minimize this growing population’s challenges and optimize its strengths. The ultimate goal is to best equip neurodivergent individuals for success—regardless of their differences.
Amen Clinics
Founded in 1989 by double-board certified psychiatrist and neuroscientist Daniel G. Amen, MD, Amen Clinics Inc. (ACI) is known as the best brain and mental health company in the world. Our clinical staff includes over 50 healthcare specialists, including adult and child psychiatrists, integrative (functional) medicine physicians, naturopaths, addiction specialists, forensic psychiatrists, geriatric psychiatrists, nutritionists, licensed therapists, and more. Our clinicians have all been hand-selected and personally trained by Dr. Amen, whose mission is to end mental illness by creating a revolution in brain health. Over the last 35-plus years, ACI has built the world’s largest database of functional brain scans—over 250,000 SPECT scans on patients from 155 countries—related to how people think, feel, and behave.
Botha M, Chapman R, Giwa Onaiwu M, Kapp SK, Stannard Ashley A, Walker N. The neurodiversity concept was developed collectively: An overdue correction on the origins of neurodiversity theory. Autism. 2024 Jun;28(6):1591-1594. doi: 10.1177/13623613241237871. Epub 2024 Mar 12. PMID: 38470140.
ADHD Aware. What Is Neurodiversity: Neurodevelopmental Conditions. https://adhdaware.org.uk/what-is-adhd/neurodiversity-and-other-conditions/
American Psychiatric Association. Exploring a Strengths-Based Approach to Neurodiversity. April 11, 2022. https://www.psychiatry.org/news-room/apa-blogs/exploring-a-strengths-based-approach-to-neurodiver
CDC. Data and Statistics on ADHD. November 19, 2024. https://www.cdc.gov/adhd/data/index.html
CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network. Data and Statistics on Autism Spectrum Disorder, May 27, 2025. https://www.cdc.gov/autism/data-research/index.html
APA, What Is Specific Learning Disorder? https://www.psychiatry.org/patients-families/specific-learning-disorder/what-is-specific-learning-disorder
Gibbs J, Appleton J, Appleton R. Dyspraxia or developmental coordination disorder? Unravelling the enigma. Arch Dis Child. 2007 Jun;92(6):534-9. doi: 10.1136/adc.2005.088054. PMID: 17515623; PMCID: PMC2066137.
Biotteau M, Chaix Y, Blais M, Tallet J, Péran P, Albaret JM. Neural Signature of DCD: A Critical Review of MRI Neuroimaging Studies. Front Neurol. 2016 Dec 16;7:227. doi: 10.3389/fneur.2016.00227. PMID: 28018285; PMCID: PMC5159484.
We're Here to Help
ADHD, autism, and other mental health conditions can’t wait. At Amen Clinics, we provide personalized, science-backed treatment plans designed to target the root causes of your symptoms. Our 360-approach includes brain SPECT imaging, clinical evaluations, innovative therapeutic techniques, medications (when necessary), and holistic lifestyle recommendations to promote the health of your brain, body, and mind. Speak to a specialist today at 888-288-9834 or visit our contact page here.