Depression, anxiety, and panic attacks:
Depression and anxiety occur in as many as 50% of Parkinson's Disease (PD) patients. Sometimes, they may be among the first
symptoms of PD, and a small number of patients, the initial symptom may be frank panic attacks, with full-blown palpations, hyperventilation, sweating,
pallor, and a feeling of impending doom. Depression may lead to loss of motivation, and the patient may not want to do anything all day. These
disorders of mood may be in small part a reaction to the disease itself, but more often result from biochemical deficiencies in the brain of neurochemicals
related to dopamine (called norepinephrine and serotonin) which are responsible for mood regulation and are reduced (like dopamine, although not
as drastically) in PD. Rarely, the depression may be so severe as to require significant psychiatric intervention. More commonly, anxiety and depression are
mild; they sometimes improve with antiparkinson therapy, but frequently require additional medications.
Disturbances of sleep:
All humans must go through a normal sleep cycle in the regular rhythm of the day, but the sleep cycle is frequently abnormal in
those with PD (insomnia). Inability to f a l l asleep is less common in PD than the
inability to stay asleep; that is, patients fall asleep with no problem, but wake
up frequently throughout the night. More problematic is the individual who catnaps throughout the day and cannot sleep at night, reversing the normal
sleep cycle. Some people have very vivid dreams (usually from too much antiparkinson medication) and may talk or thrash in their sleep; this rarely
bothers the patient, but may have a strong affect on the patientís bed partner.
Kicking and jerking of the limbs (nocturnal myoclonus) during sleep may also occur. If one wakes up, instead of getting up and wandering through the house,
it is important to try to go back to sleep to get a good nightís rest, if possible.
Dementia, memory loss, and confusion:
Problems with memory, thinking, word-finding, and other features of cognitive function (dementia) may
occur in up to 40-50% of PD patients, especially late in the disease and in older patients. These problems are usually milder than the dysfunction seen in
Alzheimerís disease and are part of the pathology of PD. When these problems occur earlier in the course, there may be more extensive involvement of the
brain with degenerating neurons demonstrating Lewy bodies (see Introduction), and this ďextended?form of PD is called diffuse Lewy body disease
(DLBD). Although occasionally Alzheimerís disease may occur together with PD, it is
important to realize that mental dysfunction may be attributed to the PD (or
DLBD) alone, without Alzheimerís. Confusion may become a problem; it is frequently worsened by antiparkinson medications.
Hallucinations and psychosis: One result of too much antiparkinson medication may be disturbances of perception, with hallucinations (seeing
people or things that arenít really there. They are usually visual, rarely auditory
(hearing). Delusions (a fixed but erroneous idea or notion) or paranoia (feeling
that people are out to get them, for example) may also occur. These symptoms constitute drug-induced psychosis, although rarely, especially in DLBD, they
may occur without any antiparkinson medications at all. Frequently, psychotic symptoms, especially when severe, may indicate an underlying complication of
dementia (see above).