Psychosis is a term used to describe a mental health condition that affects the way an individual perceives reality. It is characterised by an impaired relationship with reality, and it can include a range of symptoms.

When someone is experiencing psychosis, their thoughts and perceptions are significantly altered, affecting their sense of reality. This can lead to a range of symptoms that vary in severity and impact. Understanding what goes on in a person during psychosis involves looking at the various symptoms and how they might experience them:

Hallucinations

• Auditory Hallucinations: Hearing voices or sounds that have no external source. These voices can be critical, complimentary, or neutral, and they may command the individual to perform actions – such as telling them to self-harm, or even murder other people.
• Visual Hallucinations: Seeing things that aren’t there, which can range from shapes and colors to detailed scenes and people.
• Other Senses: Feeling touched when no one is present, smelling odors, or tasting things that have no physical source.

Delusions

• Paranoid Delusions: Believing that others are plotting harm or spying on them, even without any evidence.
• Grandiose Delusions: Having an inflated sense of self-importance or believing in having special powers, identity, or mission.
• Other Delusions: Beliefs that might involve bizarre or implausible scenarios, like thinking they are being controlled by external forces or that their thoughts are being broadcasted to others.

Disorganised Thinking

• The individual may struggle to organise thoughts coherently, which can result in disjointed speech or abruptly switching topics without logical progression. This makes communication challenging, and can be a factor in an individual to become isolated.

Disorganised or Abnormal Motor Behavior

• This can range from a lack of response (catatonia) to unnecessary and excessive movement. Behavior may be unpredictable and not aligned with the situation.

Disorganised or Abnormal Motor Behavior

• This can range from a lack of response (catatonia) to unnecessary and excessive movement. Behavior may be unpredictable and not aligned with the situation.

Emotional Experiences

• People in psychosis might feel a heightened sense of fear or be overwhelmed by their emotions. Conversely, some might feel emotionally numb or detached from their surroundings.

Cognitive Symptoms

• These can include difficulty concentrating, remembering, or making decisions. Cognitive challenges can make it hard for the person to function in daily life.

Subjective Experience

• The experience of psychosis is deeply personal and can be profoundly disorienting and frightening. Individuals may be partially or fully aware that their experiences do not align with external reality, which can be distressing. Alternatively, they may lack insight into their condition, making it difficult to seek or accept help.

It’s important to note that psychosis is a symptom, not a diagnosis in itself, and can occur in the context of various mental health conditions, including schizophrenia, bipolar disorder, and severe depression. It can also be triggered by substances, medical conditions, or extreme stress.

For example, severe sleep deprivation has shown to induce psychosis in healthy individuals in numerous studies.

Treatment typically involves a combination of medication (usually antipsychotic drugs) and psychotherapy, tailored to the individual’s specific needs and the underlying cause of their psychosis. Early intervention and comprehensive treatment are crucial for improving outcomes and helping individuals manage symptoms effectively.                                                      

The Current Prevailing Theory of Psychosis Phenomenon

The link between dopamine receptors and psychosis is a central focus in the study of schizophrenia and other psychotic disorders. Dopamine is a neurotransmitter involved in various brain functions, including mood, motivation, reward, and the regulation of movement. The dopamine hypothesis of schizophrenia, one of the most researched theories in the field, suggests that abnormalities in the dopamine system contribute to the symptoms of psychosis.

Dopamine Receptors and Their Role

Dopamine acts through dopamine receptors, which are present on the surface of certain brain cells. These receptors are classified into several types, including D1, D2, D3, D4, and D5, based on their genetic makeup and the way they affect cells. The most studied receptors in relation to psychosis are the D2 receptors. Antipsychotic medications, particularly those used to treat schizophrenia and other forms of psychosis, often target these receptors.

The Dopamine Hypothesis

The dopamine hypothesis posits that an overactivity of dopamine D2 receptors in certain brain regions, particularly in the mesolimbic pathway, contributes to the positive symptoms of psychosis, such as hallucinations and delusions. Conversely, a decrease in dopamine activity in the mesocortical pathway, affecting D1 receptors, is thought to contribute to the negative and cognitive symptoms of psychosis, such as apathy, flat affect, and impaired executive function.

Evidence Supporting the Dopamine Hypothesis

Several lines of evidence support the dopamine hypothesis of psychosis:

• Antipsychotic Medications: Most antipsychotic drugs exert their effects by blocking D2 dopamine receptors, reducing the positive symptoms of psychosis. The efficacy of these medications in managing psychosis provides indirect evidence of dopamine’s role in these disorders.
• Psychostimulant Drugs: Drugs that increase dopamine levels, such as amphetamines and cocaine, can induce psychotic symptoms in individuals without a prior history of psychosis and can exacerbate symptoms in those with psychotic disorders, suggesting a link between increased dopamine activity and psychosis.
• Neuroimaging Studies: Imaging techniques, such as PET and SPECT scans, have shown abnormal dopamine synthesis and release in individuals with schizophrenia compared to healthy controls.

Beyond Dopamine

While the dopamine hypothesis has been influential in understanding and treating psychosis, it is clear that the condition involves a complex interplay of multiple neurotransmitters and brain systems. Other neurotransmitters, such as glutamate, serotonin, and GABA, also play crucial roles in the pathophysiology of psychotic disorders.

Current research aims to develop a more comprehensive understanding of these interactions and how they contribute to the development of psychosis.