delivered the opinion of the Court.
The Court granted certiorari in this case to determine whether involuntarily committed mental patients have a constitutional right to refuse treatment with antipsychotic drugs.
I
This litigation began on April 27, 1975, when respondent Rubie Rogers and six other persons filed suit against various officials and staff of the May and Austin Units of the Boston State Hospital. The plaintiffs all were present or former mental patients at the institution. During their period of institutionalization all had been forced to accept unwanted treatment with antipsychotic drugs. 1 Alleging that forcible *294 administration of these drugs violated rights protected by the Constitution of the United States, the plaintiffs — respondents here — sought compensatory and punitive damages and injunctive relief. 2
The District Court certified the case as a class action. See
Rogers
v.
Okin,
The Court of Appeals for the First Circuit affirmed in part and reversed in part.
Rogers
v.
Okin,
The Court of Appeals found that the State has two interests that must be weighed against the liberty interests asserted by the patient: a police power interest in maintaining order within the institution and in preventing violence, see id., at 655, and a parens patriae interest in alleviating the sufferings of mental illness and in providing effective treatment, see id., at 657. The court held that the State, under its police powers, may administer medication forcibly only upon a determination that “the need to prevent violence in a particular situation outweighs the possibility of harm to the medicated individual” and that “reasonable alternatives to the administration of antipsychotics [have been] ruled out.” Id., at 656. Criticizing the District Court for imposing what it regarded as a more rigid standard, the Court of Appeals held that a hospital’s professional staff must have substantial discretion in deciding when an impending emergency requires involuntary medication. 7 The Court of Appeals reserved to the District Court, on remand, the task of developing mechanisms to ensure that staff decisions under the *297 “police power” standard accord adequate procedural protection to “the interests of the patients.” 8
With respect to the State’s parens patriae powers, the Court of Appeals accepted the District Court’s state-law distinction between patients who have and patients who have not been adjudicated incompetent. Where a patient has not been found judicially to be “incompetent” to make treatment decisions under Massachusetts law, 9 the court ruled that the parens patriae interest will justify involuntary medication only when necessary to prevent further deterioration in the patient’s mental health. See id., at 660. The Court of Appeals reversed the District Court’s conclusion that a guardian must be appointed to make nonemergency treatment decisions on behalf of incompetent patients. Even for incompetent patients, however, it ruled that the State’s parens patriae interest would justify prescription only of such treatment as would be accepted voluntarily by “the individual himself . . . were he competent” to decide. Id., at 661. 10 *298 The Court of Appeals held that the patient’s interest in avoiding undesired drug treatment generally must be protected procedurally by a judicial determination of “incompetency.” 11 If such a determination were made, further on-the-scene procedures still would be required before antipsychotic drugs could be administered forcibly in a particular instance. Ibid. 12
Because the judgment of the Court of Appeals involved constitutional issues of potentially broad significance,
13
we granted certiorari.
Okin
v.
Rogers,
II
A
The principal question on which we granted certiorari is whether an involuntarily committed mental patient has a constitutional right to refuse treatment with antipsychotic
*299
drugs.
14
This question has both substantive and procedural aspects. See
As a practical matter both the substantive and procedural issues are intertwined with questions of state law. In theory a court might be able to define the scope of a patient’s federally protected liberty interest without reference to state law.
16
Having done so, it then might proceed to adjudicate the procedural protection required by the Due Process Clause for the federal interest alone. Cf.
Vitek
v.
Jones,
445
*300
U. S. 480, 491-494 (1980). For purposes of determining actual rights and obligations, however, questions of state law cannot be avoided. Within our federal system the substantive rights provided by the Federal Constitution define only a minimum. State law may recognize liberty interests more extensive than those independently protected by the Federal Constitution. See
Greenholtz
v.
Nebraska Penal Inmates,
Where a State creates liberty interests broader than those protected directly by the Federal Constitution, the procedures mandated to protect the federal substantive interests also might fail to determine the actual procedural rights and duties of persons within the State. Because state-created liberty interests are entitled to the protection of the federal Due Process Clause, see, e. g., Vitek v. Jones, supra, at 488; Greenholtz v. Nebraska Penal Inmates, supra, at 7, the full scope of a patient’s due process rights may depend in part on the substantive liberty interests created by state as well as federal law. Moreover, a State may confer procedural protections of liberty interests that extend beyond those minimally required by the Constitution of the United States. If a State does so, the minimal requirements of the Federal Constitution would not be controlling, and would not need to be identified in order to determine the legal rights and duties of persons within that State.
B
Roughly five months after the Court of Appeals decided this case, and shortly after this Court granted certiorari, the Supreme Judicial Court of Massachusetts announced its deci
*301
sion in
Guardianship of Roe,
C
The Massachusetts Supreme Court stated that its decision was limited to cases involving
noninstitutionalized
mental patients. See
id.,
at 417, 441, 452-453,
Especially in the wake of
Roe,
it is distinctly possible that Massachusetts recognizes liberty interests of persons adjudged incompetent that are broader than those protected directly by the Constitution of the United States. Compare
Roe, supra,
at 434,
Procedurally, it also is quite possible that a Massachusetts court, as a matter of state law, would require greater protection of relevant liberty interests than the minimum adequate to survive scrutiny under the Due Process Clause. Compare
Roe, supra,
at 434,
Finally, even if state procedural law itself remains unchanged by
Roe,
the federally mandated procedures will depend on the nature and weight of the
state
interests, as well as the individual interests, that are asserted. To identify the nature and scope of state interests that are to be balanced against an individual’s liberty interests, this Court may look to state law. See,
e. g., Roe
v.
Wade,
D
It is unclear on the record presented whether respondents, in the District Court, did or did not argue the existence of “substantive” state-law liberty interests as a basis for their *305 claim to procedural protection under the federal Due Process Clause, or whether they may have claimed state-law procedural protections for substantive federal interests. 25 In their brief in this Court, however, respondents clearly assert state-law arguments as alternative grounds for affirming both the “substantive” and “procedural” decisions of the Court of Appeals. See Brief for Respondents, especially at 61, 71-72, 92-95.
Until certain questions have been answered, we think it would be inappropriate for us to attempt to weigh or even to identify relevant liberty interests that might be derived directly from the Constitution, independently of state law. It is this Court’s settled policy to avoid unnecessary decisions of constitutional issues. See,
e. g., City of Mesquite
v.
Aladdin’s Castle, Inc.,
*306 In applying this policy of restraint, we are uncertain here which if any constitutional issues now must be decided to resolve the controversy between the parties. In the wake of Roe, we cannot say with confidence that adjudication based solely on identification of federal constitutional interests would determine the actual rights and duties of the parties before us. And, as an additional cause for hesitation, our reading of the opinion of the Court of Appeals has left us in doubt as to the extent to which state issues were argued below and the degree to which the court’s holdings may rest on subsequently altered state-law foundations.
Because of its greater familiarity both with the record and with Massachusetts law, the Court of Appeals is better situated than we to determine how
Roe
may have changed the law of Massachusetts and how any changes may affect this case. Accordingly, we think it appropriate for the Court of Appeals to determine in the first instance whether
Roe
requires revision of its holdings or whether it may call for the certification of potentially dispositive state-law questions to the Supreme Judicial Court of Massachusetts, see
Bellotti
v.
Baird,
The judgment of the Court of Appeals is therefore vacated, and the case is remanded for further proceedings consistent with this opinion.
So ordered.
Notes
As used in this litigation, the term “antipsychotic drugs” refers to medications such as Thorazine, Mellaril, Prolixin, and Haldol that are used in treating psychoses, especially schizophrenia. See
Rogers
v.
Okin,
The respondents also presented constitutional and statutory challenges to a hospital policy of secluding patients against their will.
The District Court characterized liberty to make “the intimate decision as to whether to accept or refuse [antipsychotic] medication” as “basic to any right of privacy” and therefore protected by the Constitution. See id., at 1366. The court did not derive this right from any particular constitutional provision, although it did observe that the “concept of a right of privacy . . . embodies First Amendment concerns.” Ibid. In relying on the First Amendment the court reasoned that “the power to produce ideas is fundamental to our cherished right to communicate and is entitled to comparable constitutional protection.” Id., at 1367.
Under the common law of torts, the right to refuse any medical treatment emerged from the doctrines of trespass and battery, which were applied to unauthorized touchings by a physician. See,
e. g., Superintendent of Belchertown State School
v.
Saikewicz,
The District Court defined an emergency as a situation in which failure to medicate “would result in a substantial likelihood of physical harm to th[e] patient, other patients, orto staffmembers of the institution.” Id., at 1365.
The Court of Appeals termed it “intuitively obvious” that “a person has a constitutionally protected interest in being left free by the state to decide for himself whether to submit to the serious and potentially harmful medical treatment that is represented by the administration of antipsychotic drugs.”
The Court of Appeals held that the District Court had erred in requiring what it construed as an overly simplistic mathematical calculation of the “quantitative” likelihood of harm. See id., at 656.
It asserted, apparently as a minimum, that “the determination that medication is necessary must be made by a qualified physician as to each individual patient to be medicated.” Ibid.
A number of other States also distinguish between the standards governing involuntary commitment and those applying to determinations of incompetency to make treatment decisions. For a survey as of December 1, 1977, see Plotkin, Limiting the Therapeutic Orgy: Mental Patients’ Right to Refuse Treatment, 72 Nw. U. L. Rev. 461, 504-525 (1977). The Court of Appeals for the Second Circuit has held that civil commitment does not raise even a presumption of incompetence. See
Winters
v.
Miller,
In imposing this “substituted judgment” standard the Court of Appeals appears to have viewed its holding as mandated by the Federal Constitution. See
The Court of Appeals appears to have agreed with the District Court that this determination, under Massachusetts law, would require a decision by the probate court under Mass. Gen. Laws Ann., ch. 123, §25 (West Supp. 1982-1983); see ch. 201, §§ 1, 6,12 (West Supp. 1982-1983) (appointment and powers of guardians). It suggested, however, that nonjudicial procedures would satisfy the federal constitutional requirements of due process. See
The Court of Appeals again instructed the District Court to develop procedural safeguards adequate to protect the patient’s substantive interests. See id., at 661.
Constitutional questions involving the rights of committed mental pa.tients to refuse antipsychotic drugs have been presented in other recent cases, including
Rennie
v.
Klein,
Pet. for Cert. 1.
In this Court petitioners appear to concede that involuntarily committed mental patients have a constitutional interest in freedom from bodily invasion, see Brief for Petitioners 43-47, but they deny that this interest is “fundamental.” They also assert that it is outweighed in an appropriate balancing test by compelling state interests in administering antipsychotic drugs. Id., at 54-68.
As do the parties, we assume for purposes of this discussion that involuntarily committed mental patients do retain liberty interests protected directly by the Constitution, cf.
O’Connor
v.
Donaldson,
See
Although the Massachusetts court quoted this formulation from the decision of the Court of Appeals in
Rogers
v.
Okin,
See
id.,
at 435,
“The determination of what the incompetent individual would do if competent will probe the incompetent individual’s values and preferences, and such an inquiry, in a case involving antipsychotic drugs [and a noninstitu-tionalized but incompetent patient], is best made in courts of competent jurisdiction.”
Having held that a “ward possesses but is incapable of exercising personally” the right to refuse antipsychotic drugs, the Massachusetts Supreme Court viewed the “primary dispute” as over “who ought to exercise this right on behalf of the ward.” Id., at 433,421 N. E. 2d, at 51 . The Supreme Judicial Court in Roe identified six “relevant” but “not exclusive” factors that should guide the decisions of the lower courts: “(1) the ward’s expressed preferences regarding treatment; (2) his religious beliefs; (3) the impact upon the ward’s family; (4) the probability of adverse side effects; (5) the consequences if treatment is refused; and (6) the prognosis with treatment.” Id., at 444,421 N. E. 2d, at 57 . It emphasized that the determination “must ‘give the fullest possible expression to the character and circumstances’ ” of the individual patient and that “this is a subjective rather than an objective determination.” Id., at 444,421 N. E. 2d, at 56 (citation and footnote omitted).
See
id.,
at 440-441,
But cf.
id.,
at 432,
Respondents first presented this argument in a motion to dismiss or in the alternative to certify certain questions to the Supreme Judicial Court of Massachusetts, filed in this Court on October 1,1981. In their brief on the merits, respondents argue that Roe provides an alternative basis on which this Court could affirm the judgment of the Court of Appeals.
Even prior to
Roe,
the Court of Appeals concluded that Massachusetts state law, which it construed as requiring
judicial
determinations of incompetency separate from involuntary commitment proceedings, see
In
Roe
the Massachusetts court explicitly considered the implicated state interests, see
Although relying primarily on federal constitutional grounds, the respondents’ original complaint in the District Court could be construed as raising state-law guarantees either as alternative or as interrelated bases for relief. See Complaint in No. 75-1610-T (D. Mass.) (filed Apr. 27, 1975). In their briefs in the Court of Appeals, respondents relied unambiguously on state law in support of both the “substantive” and “procedural” rights that they now claim in this Court. See Brief for Plaintiff-Appellants in No. 79-1649, p. 44 (“Massachusetts law created a legal entitlement to' be free from forced medications except in emergencies . . .”); Brief for Plaintiff-Appellees in No. 79-1648, p. 54 (“[T]he lower court’s requirement that a guardian must decide whether an incompetent patient will receive psychotropic medication in a non-emergency was the correct application of state law and was not based upon constitutional authority”) (emphasis omitted).
A certification procedure is provided by Mass. Rules of Court, Sup. Jud. Ct. Rule 1:03.
