Motor

Ambitendency

Ambitendency is a pattern in which a patient, expected to carry out a voluntary action such as shaking hands, makes a series of tentative, incomplete movements toward the goal without ever reaching it, appearing caught in an unresolved conflict about whether to move at all. The hand may move toward the examiner's, stop, start again, stop again, and finally come to rest without ever completing the intended action.

This has traditionally been understood in two related ways: as a mild variety of negativism, in which careful, patient, confidence-building engagement with the patient can cause it to soften into more overt negativism if that trust is not maintained, or as a consequence of obstruction, in which a series of tentative movements occurs before the obstruction prevents completion altogether.

Recognition features

• A series of tentative, incomplete movements toward an intended goal-directed action, such as a handshake, without the action ever being completed
• The overall impression is of a patient caught in genuine conflict about whether to carry out the movement
• Often observed in negativistic patients who are being approached carefully, with efforts made to build their trust and confidence
• Can be distinguished from an obstruction-related pattern by what happens next: in obstruction, the body typically stays fixed for a time in whatever position was reached when the block occurred (perseveration of posture), which does not occur with ambitendency arising from negativism

Eliciting it at interview

• Offer a hand for a handshake or another simple goal-directed gesture, and observe closely for a hesitant, start-stop sequence of incomplete movements rather than either a clean completion or an outright refusal
• Note whether careful, confidence-building engagement seems to reduce the ambitendency, or whether reduced engagement causes more overt negativism to emerge instead, since this relationship is a recognised clinical pattern
• Check whether the body remains fixed in an intermediate position afterward (suggesting an obstruction-related process) or simply settles without completing the action (more typical of ambitendency arising from negativism)

Distinguishing features

• Differs from negativism proper, of which it can be regarded as a milder variant, in that the patient shows genuine, visible hesitation and partial movement rather than either straightforward non-compliance or reflex opposite action
• Differs from obstruction in its typical aftermath: true obstruction-related ambitendency tends to leave the body briefly fixed in an intermediate position, whereas negativism-related ambitendency does not
• Can be understood as a specific form of ambivalence expressed through the body, with visibly opposing tendencies toward and away from completing the action

Common misconceptions

• That ambitendency is simply clumsiness or physical hesitancy; the pattern reflects an underlying conflict about whether to act at all, rather than a purely mechanical difficulty
• That ambitendency and obstruction are the same thing; though related and sometimes difficult to tell apart, they can be distinguished by what happens to the body once the incomplete movement ends

Related phenomena

Negativism · Obstruction (Blocking)

Diagnostically relevant to

Schizophrenia (catatonic presentations) (links open the DSM-5 Learning Lab)

Practice this

Asked to shake hands, a patient makes a series of tentative, incomplete movements toward the examiner's hand, repeatedly starting and stopping without ever actually completing the handshake, appearing genuinely caught in conflict about whether to carry out the action. What is this? · Asked to shake hands, a patient makes no attempt whatsoever, simply refusing outright with no visible hesitation, partial movement, or apparent internal conflict, and this same flat refusal is seen across every request made of her throughout the interview. Before revealing the answer: is this ambitendency? · A patient shows an unusual, hesitant response to a requested action. Before revealing the answer, decide what distinguishes ambitendency from negativism proper. · A patient shows an unusual hesitation when asked to perform a simple action. Before revealing the answer, decide how you would assess whether this is ambitendency. · Explain why ambitendency is described as a specific form of ambivalence expressed through the body, and why this framing is clinically useful.

Illustration

When an examiner extends a hand to greet him, a patient with catatonia moves his own hand halfway toward it, stops, withdraws it slightly, moves it forward again, stops once more, and after several seconds of this back-and-forth simply lets his hand drop to his side without ever making contact.

References

• Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 8, 'Motor Disorders'.