Introduction
Bipolar disorder, formerly known as manic depression, is a mental health condition characterized by extreme shifts in mood and energy levels. People with bipolar disorder experience periods of mania or hypomania, where they feel energized, impulsive, and elevated, alternating with periods of depression, where they feel sad, hopeless, and unmotivated.
According to the Diagnostic and Statistical Manual of Mental Disorders, the key symptoms of bipolar mania include inflated self-esteem, increased talkativeness, racing thoughts, reduced need for sleep, and impulsive or risky behaviors. The key symptoms of bipolar depression include loss of energy, lack of motivation, changes in appetite, difficulty concentrating, and feelings of worthlessness or guilt.
Bipolar disorder affects about 2.8% of U.S. adults each year. It typically begins in young adulthood and is a lifelong condition with recurring episodes of mania and depression. While the exact causes are unclear, it likely involves a combination of genetic, biological, and environmental factors.
Dogs’ Sense of Smell
Dogs have a very acute sense of smell that is far superior to humans. Their sense of smell is estimated to be 10,000 to 100,000 times more sensitive than that of humans [1]. Dogs have up to 300 million olfactory receptors in their noses, compared to only 6 million in humans. Their powerful sniffers can detect scents from long distances away. Dogs are able to pick up the faintest odors drifting through the air even when the source is far away. They can determine direction, intensity, and even the estimated time a scent was left [2].
This powerful sense of smell allows dogs to detect subtle changes in human body odors. Since every person has a unique scent, dogs are able to tell people apart by their smell. Studies have shown that dogs can detect differences between the scents of identical twins. Dogs’ noses can even pick up on hormonal changes in humans that reflect mood or emotional state.
Studies on Dogs Sensing Human Emotions
Several studies have demonstrated that dogs are able to detect human emotions based on scent alone. A 2016 study published in Biology Letters tested canine ability to match emotional sounds with emotional expressions (Albuquerque, 2016, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785927/). The researchers collected sweat samples from people experiencing various emotions – fear, happiness, sadness, and neutrality. The dogs were then presented with the different sweat samples and corresponding facial expressions projected on a screen. The study found the dogs could correctly match the scent sample to the facial expression, indicating they could identify human emotions from scent.
Another 2021 study published in Animals reviewed prior research on dogs’ ability to recognize human emotions (Mota-Rojas, 2021, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8614696/). The researchers concluded that dogs are able to detect slight changes in human body odors that correspond to different emotional states. For example, they can identify increased sweat production and associated scent changes when a person is experiencing fear or anxiety. The exact mechanisms behind how dogs sense human emotions are still being investigated.
Dogs Sensing Onsets of Seizures and Hypoglycemic Episodes
There is research showing that some dogs have the ability to detect onsets of seizures or hypoglycemic episodes in humans. One study published in Frontiers in Veterinary Science found that the majority of dogs studied were able to predict seizures in their owners https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8388511/. The dogs displayed behaviors like whining, barking, pacing, and anxiousness prior to their owners having a seizure.
Dogs have also been trained to detect hypoglycemic episodes in diabetics. They are able to detect chemical changes that happen when blood sugar drops to dangerously low levels. According to Scientific American, trained dogs can detect the scent of seizures in humans as well https://www.scientificamerican.com/article/dogs-detect-the-scent-of-seizures/. This indicates dogs may be able to smell subtle biological changes happening prior to medical events.
Possible Links Between Scent and Bipolar Disorder
There is some research indicating that bipolar disorder may affect a person’s scent in subtle ways that dogs can detect. A 2012 study found that people with bipolar disorder tend to have increased olfactory sensitivity during manic states (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3281516/). This heightened sense of smell was associated with elevated mood.
Another study in 2006 showed that patients with bipolar disorder had lower odor detection thresholds compared to controls, meaning they could smell lower concentrations of odors (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1488901/). This increased olfactory acuity was present during euthymic (stable, non-depressed) states.
Researchers hypothesize that the olfactory system may be affected by the underlying pathophysiology of bipolar disorder. Structural and functional changes in the olfactory bulb and higher order olfactory processing regions may enhance odor detection in some bipolar patients. Additionally, increased serotonin levels during manic phases may boost olfactory sensitivity.
While more research is needed, these findings indicate there may be detectable scent changes associated with bipolar mood states. Dogs’ remarkably sensitive noses can pick up on even subtle shifts in human odors. This ability could potentially allow dogs to smell chemical changes related to oncoming manic or depressive episodes in their bipolar owners.
Anecdotal Accounts of Dogs Sensing Mood Changes
There are many anecdotal reports from dog owners saying their pets seem able to sense oncoming manic or depressive episodes before the symptoms fully manifest in the owner. While anecdotal, these accounts suggest dogs may detect subtle signs of mood changes.
For example, one person with bipolar disorder reported their dog would become extra clingy and attentive right before they experienced a manic episode, as if the dog was trying to comfort them (source). The dog’s behavior acted as an early warning sign of an oncoming mood swing.
Other bipolar dog owners describe their dogs whimpering, pacing, or barking excessively when the owner is having racing thoughts or becoming irritable, which are signs of a manic phase. The dogs seem unsettled and distressed in response to their owner’s change in mood.
Conversely, when the owner starts withdrawing and sleeping excessively due to depression, some dogs will try to cheer them up by bringing toys, nudging them to go for walks, and showing extra affection. It’s as if the dogs sense the melancholy mood and attempt to lift the owner’s spirits.
While more research is needed, these accounts suggest dogs may pick up on subtle clues, smells, behaviors, or energy shifts that signal a mood episode is imminent. Their close bonds with owners allows dogs to notice changes imperceptible to others.
Training Dogs to Detect Bipolar Disorder
Some research has explored the possibility of specifically training dogs to detect early signs of manic or depressive episodes in people with bipolar disorder. The idea is that dogs may be able to detect subtle changes in a person’s scent or behavior that occur prior to or during mood episodes.
According to https://psychcentral.com/bipolar/bipolar-service-dog, dogs can potentially be trained to detect oncoming manic or depressive episodes by responding to changes in a person’s scent, body language, sleep patterns, or routine behaviors. For example, a dog may notice that a bipolar handler becomes more restless, agitated, or energetic as mania approaches. The dog could then be trained to alert the handler to take medication or employ other coping strategies.
Similarly, dogs may detect signs of an oncoming depressive episode, such as sad facial expressions, changes in hygiene habits, or slowed movements. The dog could alert the handler to engage in mood boosting activities or contact their mental health provider. With proper training and bonding with a handler, dogs may learn to recognize these signals reliably.
Of course, specialized training is required to teach dogs these nuanced detection skills. Professional dog trainers can work closely with individuals with bipolar disorder to understand their unique patterns and cues. Consistent repetition and reward-based training could make bipolar service dogs quite adept at sensing oncoming episodes before obvious symptoms emerge.
Challenges and Limitations
While there are promising anecdotes of dogs sensing and responding to bipolar mood episodes, training dogs to reliably detect signs of bipolar is not without difficulties and limitations. Some key challenges include:
– Accuracy and reliability – Studies have shown dogs can detect epileptic seizures and hypoglycemic episodes with relatively high accuracy (above 90% in some cases). However, mood changes in bipolar disorder may present a more nuanced detection task (https://psychcentral.com/bipolar/bipolar-service-dog). More research is needed to determine if dogs can accurately and consistently identify oncoming manic or depressive episodes.
– Complexity of bipolar symptoms – Bipolar disorder varies greatly between individuals in terms of type, frequency and severity of mood episodes. This complexity makes it difficult to identify consistent scent patterns that dogs could detect (https://wagwalking.com/sense/can-dogs-sense-bipolar-disorder).
– Self-reporting issues – Having patients self-report mood symptoms to validate the dog’s accuracy presents challenges around reliability of patient feedback during bipolar episodes.
– Lack of formal training programs – There are few structured programs focused on training psychiatric service dogs specifically for bipolar assistance tasks compared to other medical disorders like diabetes or epilepsy.
More research and development of formalized training protocols tailored to bipolar disorder would help overcome these limitations. However, psychiatric service dogs show promise in improving quality of life for those with bipolar when utilized alongside medical treatment plans.
Other Benefits of Dogs for People with Bipolar
In addition to potentially detecting signs of bipolar episodes, dogs can provide other benefits to those living with bipolar disorder.
Studies have shown that petting dogs can lower blood pressure, reduce stress, and boost mood. The companionship of a dog can help provide comfort during depressive episodes and calm anxiety during manic states.
Having a dog encourages a more regular schedule with feeding, walking, and playtime. This routine can support sleep hygiene and consistency in daily rhythms, which is helpful for mood stability in bipolar disorder.
The responsibility of caring for a pet gives a sense of purpose and motivates some with bipolar to maintain self-care routines. Taking a dog for a daily walk also promotes physical activity.
Lastly, the unconditional love of a loyal canine companion provides constant emotional support. Dogs can alleviate loneliness and isolation, making it easier to cope with the challenges of living with bipolar disorder.
Conclusion
Based on the current research, there is some anecdotal and preliminary scientific evidence that dogs may be able to sense oncoming manic or depressive episodes in people with bipolar disorder. However, the research is still limited and more studies need to be done to determine if dogs can reliably and accurately detect changes in mood and behavior associated with bipolar disorder.
Some of the key findings so far show that dogs can detect changes in odor that are linked to seizures, hypoglycemic episodes, and possibly mood disorders like bipolar. Their powerful sense of smell allows them to pick up on subtle chemical changes in the body that humans cannot detect. Additionally, dogs are very in tune to human behavior and body language, allowing them to notice slight changes that may signal a shift in mood.
While these early findings are promising, the ability of dogs to accurately and consistently detect onsets of bipolar episodes has not been thoroughly proven. Controlled studies with larger sample sizes are needed. It is also not yet understood exactly how dogs make these detections – is it based on scent alone or changes in behavior? More research is required to determine if specialized training could reliably teach dogs to identify and alert to bipolar mood changes.
In summary, while some people have noticed their dogs reacting differently during bipolar episodes, more research is still needed before we can conclude definitively that dogs can sense bipolar disorder.