Serotonin deficiency may very well play a role in a wider variety of mental illnesses than any other single variable. Without enough serotonin to calm the brain, individuals may suffer many different ailments, particularly those that involve anxiety , obsessions , compulsions , or insomnia . If obsessing over unpleasant thoughts plays a role in one's depression , the SSRIs can prove valuable as antidepressants , although simply regulating brain chemistry alone does not help the person learn new habits. When medication is needed to fix a problem with brain chemistry, the individual probably still needs counseling or behavioral retraining. It can interfere with the ability to focus attention and think clearly.
Excessive serotonin is likely to produce hypersomnia , excessive sleep.
It is involved in most behaviors, including anxiety states. This inhibitory neurotransmitter reduces the brain's electrical activity. The brain needs its electrical activity, of course, but too much can produce many problems. Among the various problems related to GABA deficits are anxiety and epilepsy. Without enough GABA, brain cells fire more than they should and keep the brain charged up.