According to Ray Price, Nixon sometimes took them in together. Nixon also took dilantin, recommended by Jack Dreyfus. That medicine is usually prescribed to treat and prevent seizures, but in Nixon's case it was for depression. His periodic overindulgences, especially during stressful times such as during Apollo 13, concerned Price and others, including then-advisor Ehrlichman and long-time valet Manolo Sanchez.[318] Author and former British politician David Owen deemed Nixon an alcoholic.[319][320]
Biographer Elizabeth Drew summarized Nixon as a "smart, talented man, but most peculiar and haunted of presidents".[321] In his account of the Nixon presidency, author Richard Reeves described Nixon as "a strange man of uncomfortable shyness, who functioned best alone with his thoughts".[322] Nixon's presidency was doomed by his personality, Reeves argues:

He assumed the worst in people and he brought out the worst in them ... He clung to the idea of being "tough". He thought that was what had brought him to the edge of greatness. But that was what betrayed him. He could not open himself to other men and he could not open himself to greatness.