Thinking is a biologically demanding task. It involves the firing of neurons which requires plenty of neurotransmitters, and even though these are reuseable to some extent, they do get depleted. Depletion of neurotransmitters generally results in reduced mental performance, which may include difficulty concentrating, slowed reasoning, decreased learning efficiency, impaired recall, reduced coordination, lowered moods, inability to cope, increased response times, and mental fatigue. This also generally increases the likelihood of human error on tasks and activities performed. Stress causes neurotransmitters to be depleted even faster. The brain's neurotransmitters need to be replenished frequently, made by the body from substances ingested in the diet. Maintaining neurochemicals at optimal levels has a corresponding effect on brain performance, supporting improved mental agility and stamina, even beyond the individual's normal limits.
As the brain ages, its ability to produce and maintain youthful levels of neurotransmitters declines. Thus, the theory is that by providing the brain with ample raw materials to make the neurotransmitters it needs can restore them to more youthful levels to help maintain cognitive function at vigorous youthful levels as well.
Dopaminergics
Dopaminergics are substances which affect the neurotransmitter dopamine or the components of the nervous system which utilize dopamine. Dopamine is produced in the synthesis of all catecholamine neurotransmitters, and is the rate limiting step for this synthesis. Dopaminergic nootropics include dopamine precursors and cofactors, and dopamine reuptake inhibitors:
- L-dopa - Precursor to the neurotransmitter dopamine, general nootropic, anti-depressant.
- Phenylalanine - Precursor to dopamine, general nootropic, anti-depressant, sleep reducer.
- Tyrosine - Precursor to dopamine, general nootropic, anti-depressant, sleep reducer.
- Theanine - Found in tea. Increases serotonin, GABA and dopamine levels in the brain. Increases alpha wave-based alert relaxation.
- Deprenyl - Inhibits MAO B (an enzyme that breaks down dopamine) thus raising dopamine by partially inhibiting its breakdown.
Neurotransmitter Serotonin
In order to increase the levels of the neurotransmitter serotonin the most effective way is taking serotonin reuptake inhibitors, which are also called antidepressants.
Anti-depression, adaptogenic and mood stabilization
Depression and depressed mood negatively affect cognitive performance. Feelings of sadness, guilt, helplessness, hopelessness, anxiety, and fear caused by depression detract from productive thought, while apathy (which is also induced by depression) is the lack of motivation and driving moods (like curiosity, interest, determination, etc.) Other symptoms include disturbed sleep patterns, mental fatigue and loss of energy, trouble concentrating or making decisions, and a generalized slowing and obtunding of cognition, including memory. Obviously, removing these effects improves intelligence and mental performance, and therefore, counteracting and preventing depression are effective nootropic strategies. There is a high correlation between depression and a reduction or depletion of neurotransmitters (dopamine, norepinephrine, and serotonin) in the brain, therefore it is no surprise that increasing the brain's supply of neurotransmitters alleviates (or at least reduces the symptoms of) most depressions. Stress is another major factor in neurotransmitter depletion, being both a cause and effect of it (creating a vicious downward spiral), therefore stress management and anti-stress substances are also very useful nootropic strategies.
All of the "nergics" listed above have been found to increase stress tolerance and alleviate depression (by replenishing or increasing the brain's supply of specific neurotransmitters), especially when used in precursor/co-factor combinations.
Here are some more nootropics which affect mood and stress:
- Vasopressin - Drug. Memory hormone produced by the pituitary gland which improves both memory encoding and recall. Rapidly counters chronic apathy syndrome and drug-induced vasopressin depletion.